Eh E h a d F u e l D is p e n s e r s
Maintenance Manual & Operation | Maintenance Handbook Contents MAINTENANCE MANUAL
PREFACE INFORMATION INFORMATION FOR USERS SAFETY ICONS 1. BRIE BRIEFF INTRO INTRODU DUCT CTIO ION N 2. MAIN MAIN TECHNI TECHNICAL CAL PARA PARAMET METERS ERS 3. CONSTR CONSTRUCT UCTION ION & WORKING WORKING PRINC PRINCIPL IPLEE 4. GEAR PUMP COMBINA COMBINATION TION PUMP PUMP & PRINCIPLE PRINCIPLE 5. FLOW FLOW METE METER R & PRINCI PRINCIPLE PLE 6. ELECTR ELECTRONI ONICC CONT CONTROL ROL UNIT UNIT 7. INSTALLA INSTALLATION TION OF FUELLING FUELLING DISPENSER DISPENSERSS 8. INSTALLA INSTALLATION TION OF ELECTRICAL ELECTRICAL EQUIPME EQUIPMENT NT 9. MAIN MAINTE TENA NANC NCEE 10.FAILURE & SOLUTION 11.SKETCH FOR INSTALLATION VANE PUMP 12.SKETCH FOR INSTALLATION GEAR PUMP 13.SKETCH FOR INSTALLA INSTALLATION TION SUBMERSIBLE PUMP ACCESSORIES FREE SPARE PARTS (LCF-90 GEAR PUMP AND LFM-85 FLOW METER) FREE SPARE PARTS (LFYP-50 VANE PUMP AND LMF-65 FLOW METER)
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OPERATION | MAINTENANCE HANDBOOK
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1. 2. 3. 4.
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MAINTE MAINTENAN NANCE CE OF THE FUEL FUEL DISPEN DISPENSER SER POINTS TO NOTE NOTE FOR FOR MAINTENA MAINTENANCE NCE PERSONN PERSONNEL EL INSTALLA INSTALLATION, TION, TESTING TESTING & ADJUSTMEN ADJUSTMENTT OF FUEL DISPENSER DISPENSER CONSTRUCTI CONSTRUCTION ON & WORKING WORKING PRINCIPLE PRINCIPLESS OF FUEL DISPEN DISPENSER SER SECTION 1: CONSTRUCTION OF FUEL DISPENSER SECTION 2: WORKING PRINCIPLES OF FUEL DISPENSER 5. CONSTRUCTI CONSTRUCTION ON & PRINCIPLES PRINCIPLES OF GEAR PUMP & VANE VANE PUMP PUMP SECTION 1: CONSTRUCTION OF PUMP SECTION 2: OPERATION & MAINTENANCE OF OIL PUMP SECTION 3: FAULT ANALYSIS FOR OIL PUMP 1
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Maintenance Manual & Operation | Maintenance Handbook Contents continued...
5. CONSTRUCTION CONSTRUCTION & PRINCIPLES PRINCIPLES OF GEAR GEAR PUMP PUMP & VANE VANE PUMP PUMP SECTION 4: THINGS TO NOTE DURING DISMANTLING & ASSEMBLY OF OIL PUMPS 6. STRUCTURES STRUCTURES & WORKING WORKING THEORY THEORY OF FLOW FLOW METER METER SECTION 1: STRUCTURES & WORKING THEORY OF FLOW METER SECTION 2: FAULTS FAULTS & MAINTENANCE OF FLOW METER 7. CONSTRUCTION CONSTRUCTION & WORKING WORKING PRINCIPLE PRINCIPLE OF AUTOMA AUTOMATIC TIC NOZZLE NOZZLE & SOLENOID VALVE VALVE SECTION 1. CONSTRUCTION & WORKING PRINCIPLE OF AUTOMATIC AUTOMATIC NOZZLE SECTION 2: STRUCTURE & PRINCIPLE OF WORK OF A SOLENOID VAL VALVE VE 8. ELECTRONIC ELECTRONIC PARTS PARTS OF OF EHAD EHAD DISPENS DISPENSER ER 9. FUEL DISPENSER DISPENSER – DETECTIN DETECTING G MALFUNC MALFUNCTION TION 10.DESIGN OF A PETROL STATION STATION SECTION 1: BUILDING REQUIREMENT OF PETROL STA STATION SECTION 2: STORAGE TANK AND PIPELINE SECTION 3: BRIEF INTRODUCTION ON THE KNOWLEDGE OF EXPLOSION PROOF SECTION 4: PRINCIPLES OF SELECTING EXPLOSION PROOF EQUIPMENT
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Maintenance Manual & Operation | Maintenance Handbook Contents continued...
5. CONSTRUCTION CONSTRUCTION & PRINCIPLES PRINCIPLES OF GEAR GEAR PUMP PUMP & VANE VANE PUMP PUMP SECTION 4: THINGS TO NOTE DURING DISMANTLING & ASSEMBLY OF OIL PUMPS 6. STRUCTURES STRUCTURES & WORKING WORKING THEORY THEORY OF FLOW FLOW METER METER SECTION 1: STRUCTURES & WORKING THEORY OF FLOW METER SECTION 2: FAULTS FAULTS & MAINTENANCE OF FLOW METER 7. CONSTRUCTION CONSTRUCTION & WORKING WORKING PRINCIPLE PRINCIPLE OF AUTOMA AUTOMATIC TIC NOZZLE NOZZLE & SOLENOID VALVE VALVE SECTION 1. CONSTRUCTION & WORKING PRINCIPLE OF AUTOMATIC AUTOMATIC NOZZLE SECTION 2: STRUCTURE & PRINCIPLE OF WORK OF A SOLENOID VAL VALVE VE 8. ELECTRONIC ELECTRONIC PARTS PARTS OF OF EHAD EHAD DISPENS DISPENSER ER 9. FUEL DISPENSER DISPENSER – DETECTIN DETECTING G MALFUNC MALFUNCTION TION 10.DESIGN OF A PETROL STATION STATION SECTION 1: BUILDING REQUIREMENT OF PETROL STA STATION SECTION 2: STORAGE TANK AND PIPELINE SECTION 3: BRIEF INTRODUCTION ON THE KNOWLEDGE OF EXPLOSION PROOF SECTION 4: PRINCIPLES OF SELECTING EXPLOSION PROOF EQUIPMENT
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Maintenance Manual
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PREFACE Thank you for choosing EHAD fuel dispensers. manufactured by LANFENG MACHINE CO. LTD. Our fuel dispensers are designed to fuel motor vehicles and are equipped to measure the volume and cost of the fuel being dispensed. We are continuously making improvements to our machinery to enhance the performance and reliability of each and every part. This manual, therefore is revised periodically, however the content will stay consistent with the product. This manual is a detailed presentation of the methods and procedures for operation of the product machinery. Please read the manual carefully before installation and operation of fuel dispenser. Notice
Avoid any repairs or changes that may impair the performance of the fuel dispenser. The structure and appearance of the fuel dispenser is certified by the National Anti-Explosive Administration. The metric performance of the fuel dispenser is approved by the General Administration of Quality Supervision, Inspection and Quarantine of PRC. Please contact the sales and service department if you have any questions about this manual. Headquarters: No 8 Gaoyi Rood, Hi-Tech Park, Wenzhou Economin Development Zone, Wenzhou, Zhejiang Office Tel: (+86-577) 86581398, 86581399 Service Tel: (+86-577) 86581391 Sales Tel: (+86-577_ 86585888, 86587777 Fax: (+86-577) 86581392 Website: www.chinalanfeng.com Email:
[email protected] Zip Code: 325011
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INFORMATION FOR USERS The Zhejiang Lanfeng Machine Co., Ltd., Series JDK50 fuel dispensers, are manufactured under strict quality controls and the metric test is measured against the national metric standard. Users should always examine the metric accuracy. If any errors are found, please apply to the metric administration for examining. Zhejiang Lanfeng Machine Co., Ltd., and its agents have an obligation to cooperate with users and metric administrations to examine the metric accuracy. However, they do not pay the following fees: cost of examination, any penalty to users, and any costs caused by the metric errors. Please take the original object as standard if any modification to the specification, model or installation of Lanfeng Products has been made.
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SAFETY ICONS DANGER No Smoking Stop running the engine when fueling
WARNING Check the variety of fuel before refueling
The wrong fuel could cause the vehicle to stop suddenly when driving resulting in an accident
Don’t open nozzle when refueling
The fuel will gush out if the lever of the nozzle is unintentionally touched
WARNING Nozzle spout must be safely inserted into the tank inlet
If the spout is not inserted safely into the tank inlet it would cause static resulting in a fire It would easily start a fire if the spout fell from the tank inlet during refuelling
WARNING Do not leave the gas station when refueling Avoid overflow due to a malfunction of the dispenser
Turn the lever of the nozzle off and stop the pump if an overflow occurs
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WARNING Please refuel in the appointed container
In order to avoid a fire caused by static, do not pump gasoline into a polythene container
Please replace the nozzle when fueling is completed Avoid fuel gushing out when refuelling next time
Please replace the vehicles inlet tank cover tightly when fuelling is complete Avoid fuel overflowing and causing a fire.
WARNING If gasoline leaks ...
Please lead person to a safe place
Scatter sand on the leaking fuel
Ensure that you are equipped with a Fire Extinguisher
Prohibit the entrance of people and vehicles
If a fuel fire occurs ...
Lead person to a safe place
Contact the fire department immediately
Extinguish the fire as soon as possible
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1. BRIEF INTRODUCTION The series JDK50 Lanfeng fuel dispensers are designed and manufactured strictly according to laws, statutes, codes and standards, of The National Standard of Fuel Dispenser for Motor Vehicles (GB/T91/1-2001), the Examining Regulations for Fuel dispensers (JJG443-98), and The Outline for the Figuration of Fuel Dispensers (JJF1060-1999). All units have passed these tests and examinations implemented by the national administration for measurement, quality and safety. The series JDK50 Lanfeng fuel dispensers are characterised by a unique design and novel appearance. It has high metric accuracy, and high flow velocity. The computer adopts advanced technology and high quality electronic elements and has reliability, high accuracy, full function, easy operation, and convenient maintenance. Lanfeng fuel dispensers and all electronic elements are all anti-explosive and have been awarded all the national anti-explosive certificates. This manual is used for the following types of fuel dispensers: JDK50C1111 JDK50C2221 JDK50D1111 JDK50
(1) Common pump (2) Submarine pump
JDK50D1112 JDK50D2121 JDK50D2122
No of Flow Meter
JDK50D2221 JDK50D2222 JDK50D4241
Number of products
JDK50D4242 JDK50D6361 JDK50D6362
Number of Nozzles Series, for example C, D
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2. MAIN TECHNICAL PARAMETERS Metric Accuracy
± 0.3%
Range of Flow
5-50 L/min, 9-90 L/min
Measurable Minimum
5L
Noise
¡Ü 80dB(A)
Vacuum of Input
¡Ý 0.060Mpa
Range of Single Count
0.00-9,800.00 L or Sale
Range of Accumulative Count
0.00-9999999,999.99 L or Sale
Range of Price
0.01 – 99.99 Price/L
Diameter of Input Pipe
38mm (1.5 inch)
Oil Pipe
Diameter 19mm and Static Wire Diameter 25mm and Static Wire
Power Supply
AC380V ± 20% 50 Hz ± 1 AC220V ± 20% 50 Hz ± 1
Rating Power
0.75 LW
Ambient Humidity
45% - 85%
Ambient Temperature
-40ºC – +60ºC
Anti-explosive ID
Exd II AT3 Exdm[ib]ib II At3
Anti-explosive Certificate Number
CE001014 CE011154 CE011155 CE011156 Ce011157
License of Manufacturing Metric Instrument
9
00000625
3. CONSTRUCTION & WORKING PRINCIPLE JDK50C1111 One Product One Nozzle Fuelling Dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
Key Board Nozzle Holder Nozzle Fuel Indicator Hose Nameplate Electronic Control Unit Solenoid Valve Impulse Sensor LFM-65 Flow Meter LFYP-50 Vane Pump Power Box Ex-Motor Flexible Pipe and Flange Plate Body
JDK50C2221 Two Products Two Nozzles Fuelling Dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
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Key Board Nozzle Holder Nozzle Fuel Indicator Hose Nameplate Electronic Control Unit Solenoid Valve Impulse Sensor LFM-65 Flow Meter LFYP-50 Vane Pump Power Box Ex-Motor Flexible Pipe and Flange Plate Body
JDK50D1111 One Product One Nozzle Fuelling Dispenser
The Main Framework “Lan Feng” JDK50D1111, single nozzle, single product, fuelling dispenser, consists of an antiexplosive motor, gear pump, meter, anti-explosive sensor, automobile shut-off nozzle, and computer installation (keyboard, display board, and electronic control unit). 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.
Electronic control Unit Key Board Impulse Sensor LFM-85 flow Meter Frame LFCP-90 Gear Pump EX-Power Box EX-Motor Flexible Pipe and Flange Solenoid Valve Nozzle Nozzle Holder Hose Breakaway Fuel Indicator Elbow Nameplate
JDK50D2221 Two Products Two Nozzles Fuelling Dispenser
The Main Framework “Lan Feng” JDK50D2221, two nozzles, two products, fuelling dispenser, consists of an antiexplosive motor, gear pump, meter, anti-explosive sensor, automobile shut-off nozzle, and computer installation (keyboard, display board, and electronic control unit). 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 11
Electronic control Unit Key Board Frame Impulse Sensor LFM-85 flow Meter Solenoid Valve LFCP-90 Gear Pump EX-Power Box Flexible Pipe EX-Motor Nameplate Nozzle Nozzle Holder Hose Breakaway Fuel Indicator Elbow
JDK50D2121 One Product Two Nozzles Fuelling Dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
Electronic Control Unit Key Board Solenoid Valve Impulse Sensor LFM-85 Flow Meter LFCP-90 Gear Pump Ex-Power Box EX-Motor Nameplate Wavy Pipe and Flexible Flange Nozzle Holder Nozzle
JDK50D4241 Two Products Four Nozzles Fuelling Dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
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Electronic Control Unit Key Board Solenoid Valve Impulse Sensor LFM-85 Flow Meter LFCP-90 Gear Pump Ex-Power Box EX-Motor Nameplate Wavy Pipe and Flexible Flange Nozzle Holder Nozzle
JDK50D6361 Three Products Six Nozzles Fuelling Dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
Electronic Control Unit Key Board Solenoid Valve Impulse Sensor LFM-85 Flow Meter LFCP-90 Gear Pump Ex-Power Box EX-Motor Nameplate Wavy Pipe and Flexible Flange Nozzle Holder Nozzle
JDK50D1112 One Product One Nozzle Submersible Pump Fuelling dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
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Top Cover Fuel Indicator Electronic Control Unit Key Board Solenoid Valve Impulse Sensor EX-Power Box Filter LFM-85 Flow Meter Fuel Inlet Nameplate Nozzle Holder Nozzle
JDK50D2222 Two Products Two Nozzles Submersible Pump Fuelling dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
Top Cover Fuel Indicator Electronic Control Unit Key Board Solenoid Valve Impulse Sensor EX-Power Box Filter LFM-85 Flow Meter Fuel Inlet Nameplate Nozzle Holder Nozzle
JDK50D6362 Three Products Six Nozzles Submersible Pump Fuelling dispenser
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
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Top Cover Fuel Indicator Electronic Control Unit Key Board Solenoid Valve Impulse Sensor EX-Power Box Filter LFM-85 Flow Meter Fuel Inlet Nameplate Nozzle Holder Nozzle
Principle
Starting the motor, and the motor drives a pump to pump fuel from a tank through pipe and flexible pipe into the filter of the pump. After filtering, the fuel is compressed and then pumped into the air separator, built into the pump, which separates gas from the fuel, and the gas is discharged outside at the same time. The compressed fuel moves the four pistons. When the four pistons have completed a cycle, a specific amount of fuel is transmitted, and simultaneously the shaft drives the impulse to rotate, encode and output the digital pulse. The electronic control unit receives the digital pulse, accounts, stores, and displays all the data involved. The fuel goes through the fuel indicator, the nozzle, and into the tank of a vehicle.
Principle Diagram of JDK50 Fuelling Dispenser
Power Supply
Display Board
Key Board
Ex-Power Box
Electronic Control Unit
SSR Relay
Ex-Impulser
Ex-Motor
Flow Meter
Solenoid Valve
Pump
Tank
Nozzle
Discharger Gas
Direction of Current Signal & Mechanical Movement....... Direction of Fuel..........................................................
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Fuel Container
4. GEAR PUMP CONSTRUCTION & PRINCIPLE LFCP-90 Gear Pump
CONSTRUCTION The gear pump is composed of a gear wheel, an air separator, and other parts. It is made of aluminium alloy, so it is small, light, and has good performance. 1. 2. 3. 4. 5. 6. 7. 8. 9.
Inlet Filter Air Separator Outlet Valve Bypass Valve Inner Gear Outer Gear Cover Outlet Filter Body
Principle
The inner gear revolving in clockwise direction in high revolution results in a low-pressure space and a high-pressure space to complete the process of sucking and pumping fuel. The bypass valve consists of a valve seat, a valve core, a spring and an adjustment bolt. When the pump runs in normal operation, the low-pressure space and the high-pressure space are isolated. When the nozzle is shut off, or the fuel cannot be discharged, high rising oil pressure pushes the valve core to move to the right. This leads the fuel discharged, from the highpressure space to the low-pressure space, therefore the fuel cycles within the pump and the oil pressure reduces. The work pressure can be adjusted by adjusting the spring of the bypass valve. There are two filters in the pump, inlet filter and outlet filter (marked STRAINER), which should be cleaned periodically.
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LFYP-50 Vane Pump
CONSTRUCTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.
Body Oil Filter Vane Pump Conducting Flake Connecting Pipe Top Cover Vent Hole Connecting Plate Separate valve Floater Lever Return Valve Discharge Valve Bypass Valve
Principle
The LFYP-50 Vane Pump is a combination of a Vane Pump with an air separator cast in aluminium alloy which is small and light. The pump is a vane pump with a locating ring. There is no high-pressure space in the air separator and there is a returning floater system in the normal pressure space. The vent pipe also has a centrifugal effect. The high-pressure connecting pipe, the discharge valve, and the bypass valve are all in one shell. Under pressure the oil in the pump flows through the high-pressure connecting pipe. The discharge valve enters the metric exchanger, pushes four pistons to reciprocate and discharge oil in a fixed volume. At the same time, air vents through the vent hole and a small amount of oil accumulates in the normal pressure space. When the level of the oil reaches a certain height, the returning floater will rise and some of the oil will return to the low-pressure space in the pump. The operating pressure of the pump can be adjusted by changing the tension of the spring on the bypass valve. When the nozzle is closed, the oil will circulate automatically in the pump. The air separator uses a centrifugal venting system so that it can eliminate the air effectively. Great–volume normal pressure space can hold some oil to avoid being full or empty.
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LFTP-80 Gear Pump
CONSTRUCTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.
Bottom cover Outer gear Inner Gear Pump cover Oil filter Shell Top Cover Air outlet Floater Oil cup Bolt of Oil hole Oil felt Oil felt push cover Wheel Half circle V type oil seal Sheath of front shaft Sheath of rear shaft
Principle
The LFTP-80 Gear pump mainly consists of internal and external gear pump, outlet and inlet of oil valve, oil filter, relief valve, air hole and oil floater. When the motor drives the external gear to rotate, the internal and external gear will mesh so there will be zones of low pressure and high pressure to finish the process of oil suction and compression. Relief valve keeps constant pressure and pressure relief. Normally the system pressure does not exceed working pressure, then start to fuel. When the nozzle is blocked or fuelling is stopped, the system pressure exceeds the working pressure and the relief valve opens in order to remove oil from the high pressure zone to the low pressure zone to control the oil pressure and to keep oil circulating in the pump. The air separator hole is used for oil and gas separation to drive high pressure gas oil into the constant pressure antrum. When the liquid reaches a specific level the dobber floats and oil flows back to the low pressure antrum. Attention: Oil filters require regular cleaning.
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5. FLOW METER CONSTRUCTION & PRINCIPLE LFM-85 Flow Meter
CONSTRUCTION The flow meter is composed of an aluminium alloy body, connecting lever, distributing valve and a shaft. It is highly accurate and has a long life span. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.
Bottom Cover Steel Ball Sleeve of Crank Crank Assembly Bottom Cover Seal Body Side Cover Seal Side Cover Rear Cover Assembly Sleeve Connecting Lever Hexangular Bolt Crank Gasket Distributor Valve Seat Top Cover Seat Bolt Gasket Screw Gasket of Distributor Valve Distributor Valve Spring Top Cover Impulse Sensor
Principle
The main parts are made from stainless steel and advanced industrial plastic. They are anticorrosive, highly wearable and sealed. The Driving Shaft is a “push and pull” drive constituted by a connecting lever and a crank. It has no intermission, no concussion, and no abnormal voice. When the driving shaft runs, it drives the shaft of the sensor producing an impulse which is then input into the computer. The hand wheel, for accuracy, can be adjusted according to errors. When it is turned to the right, the delivery capacity will be reduced; when turned to the left the delivery capacity will be increased. It is easy, accurate and stable. The meter can be adjusted one hole at a time and can also be adjusted by a half a hole. One hole is about 0.05%. After adjustment, insert the pin and seal with lead. When the high-pressure fuel comes into the meter, it drives four pistons to complete an operating cycle. When the crank turns around, the volume of the fuel ejected by an operating cycle is 0.5L.
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LFM-65 Flow Meter Construction
The flow meter shown in Fig 9 is composed of an aluminium alloy body, a connecting lever, a distributing valve, and a shaft. It has a high accuracy and long life. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.
Bottom Cover Steel Ball Sleeve of Crank Crank Assembly Bottom Cover Seal Body Side Cover Seal Side Cover Rear Cover Assembly Sleeve Connecting Lever Hexangular Bolt Crank Gasket Distributor Valve Top Cover Seat Bolt Valve Gasket Screw Gasket of Distributor Valve Seat Distributor Valve Spring Top Cover
Principle
The main parts are made from stainless steel and advanced industrial plastic. They are anticorrosive, highly wearable and sealed. The Driving Shaft is a “push and pull” drive constituted by a connecting lever and a crank. It has no intermission, no concussion, and no abnormal voice. When the driving shaft runs, it drives the shaft of the sensor producing an impulse which is then input into the computer. The hand wheel, for accuracy, can be adjusted according to errors. When it is turned to the right, the delivery capacity will be reduced; when turned to the left the delivery capacity will be increased. It is easy, accurate and stable. The meter can be adjusted one hole at a time and can also be adjusted by a half a hole. One hole is about 0.05%. After adjustment, insert the pin and seal with lead. When the high-pressure fuel comes into the meter, it drives four pistons to complete an operating cycle. When the crank turns around, the volume of the fuel ejected by an operating cycle is 0.5L.
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LFM-70 Flow Meter
CONSTRUCTION The Meter comprises a shell of cast iron, active plate, piston rod, distribution valves, shafts and other parts. The international standard performance has a high accuracy measurement, large flow rate range, long life, etc. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.
Top Cover Active plate Ceramic ball Support Distributable valve Top pad Shell Bottom pad Bottom cover Piston Rod Pad Steel ball Tri-claw support Gasket
Principle
The key components are made of stainless steel, ceramics and advanced engineering materials with corrosion resistance, friction-proof and good dynamic sealing performance. The shaft is driven by a type of tension-compression structure comprising the piston rod, active tri-claw support, and gear with non-stop, no impact, no abnormal noise. A convenient hand wheel provides several levels of accurate and stable adjustments of 0.1% each; Clockwise to increase and counter-clockwise to decrease. The pin and seal must be inserted as soon as the adjustment has been completed. Fuel, under high pressure from the pump, passes through the meter to drive the three pistons thus completing a work cycle. The fuel is discharged at a rate of 0.5 litres per cycle.
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6. ELECTRONIC CONTROL UNIT Layout of JDK 50C & JDK 50D Key Board
Layout of Display Board LITER SALE
PRICE
KEY
DESCRIPTION
Clear the number inputted; Clear the shift amount or cash after displaying when the switch is set “Setting” Input the decimal point Change the unit price when the switch Power on and fuel, when the switch
is set “Setting” is set “Fuelling”
Stop motor after fuelling Display the shift amount and the total amount and clear the shift amount Switch between Litre and Sale; Set LNF – The litre number not fuelled when chief solenoid valve is switched off When power off, press this key to display the last amount Fuel, when the switch is set “Operating”; Change unit price and/or clear or query shift amount and total amount, when the switch is set “Setting” 00.00
Digital input from Right to Left
OPERATING GUIDE 1. Power On
Set Unit Price
Set the switch on “Operating”, pull out the key, turn on the power. The keyboard will display “88888” and the display board will display “96” fully, the electronic control unit will reset automatically. This means the dispenser is ready to work.
1. Set the switch on “Setting” and press the key then the Keyboard displays former unit price. Press the key to clear it. 2. Press the digital key to input new unit price. The last two digits are decimal - DO NOT input the decimal point. Press the key to clear it when inputting a wrong number. 3. Set the switch on “Operating” and pull out the key. 22
OPERATING GUIDE 1. Press the key until Keyboard displays “P O” 2. Press the digital keys to input the preset sale. The keyboard displays the number. The sale number inputted CANNOT be less than the unit price and the decimal part CANNOT be more than two digits. 3. Press the key or take up the nozzle for fuelling. The pump will stop when the sale meets the preset sale number. A. The sale is invalid when price is zero. Fueling Preset B. The preset sale number must be less than 9999. Sale C. The preset sale number is valid only once. The preset sale number automatically returns to zero when the preset sale number is met or at end of fuelling. D. The Display Board displays zero and then begins counting when the nozzle is taken up or the key is pressed. E. The motor automatically stops when the preset sale number is met. 1. Press the key until the panel displays “L O” 2. Press the digital keys to input the litre. The keyboard displays the litre Fueling Preset number. The litre number inputted must be more than 1L and less than Litre 99L. 3. Press the key or take up the nozzle to fuel. The pump will stop when the litre number meets the preset one. Fueling NonPreset Number
Displaying Shift or Total Amount & Clearing Shift Amount
Display Current Litre or Cash Number Display After Power Failure
1. 2.
Press the key or take up the nozzle to start fuelling. After fuelling, put the nozzle on the bracket or press the key to stop the pump, at the same time sale and litre number are shown on the Display Board.
1. Set the switch on “Operating” and press the key, then the keyboard displays the litre number (L) or the sale number (P) of the shift amount. If the number is more than 9999, the keyboard will display the number on two screens. 2. Set the switch on “Setting” and press the key, then press the key. The Display Board displays the litre number (L) or the sale number (P) of the total amount. If the number is greater than 999999, the Display Board will display the number on two screens. Set the switch on “Operating” and press the key then the keyboard displays “C” and the shift amount at Litre or Yuan. Now set the switch on “Setting” and press the key to clear the shift amount. 1.
After fuelling, press the key sale number.
1.
If Power goes off when fuelling, press the key amount or litre and sale.
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and
to display the current litre or to display fuelled
OPERATING GUIDE 1. Change LNF
Set the switch on “Setting” and press the key, then the keyboard displays “D” and the former Cut-off Valve at. Press the key to clear old one. 2. Input the new Cut-off Valve at, which should be between 0.00 and 0.99. After inputting, set the switch on “Operating” and the new Cut-off Valve at is in operation automatically.
7. INSTALLATION OF FUELLING DISPENSERS 1.
The fuel dispenser is designed to be installed and used outdoors. The design of service stations should be in accordance with GB50156-92 “The design criteria of small oil storerooms and service stations for automobiles” and GBJ16-87 “The fire provision of architectural design”. The waterproof shed should be constructed to cover, in any season, and the height should be not less than 4.5 metres. The fuelling region should be 0.2 meters higher than the ground.
2.
The design of oil tanks and oil pipelines should be consigned to a local design department and should be approved by the local fire department. The consumer should not design it personally, to ensure that the system is safe.
3.
The base of the fuel pump should be installed in the concrete floor. Settle the fuel pump with bolts. The size and position of the input holes are displayed as figure F-12. The center of the output hole of the underground pipeline and the input hole should be aligned because the valve pipe connecting the two hole has a very small displacement margin to avoid the valve pipe being broken off.
4.
The underground oil pipe should be a seamless galvanized steel pipe with a diameter of 38mm. The connection of the oil pipe should be sealed with polyethylene and the oil pipe should be tested under 0.2Mpa.
5.
All of the lines, such as the power line, signal line, and the down-lead line, should be buried in the concrete floor. The tunnel should be filled with loess.
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8. INSTALLATION OF ELECTRICAL EQUIPMENT 1.
The fuel pump operates in explosive and dangerous surroundings. According to Clause 2.5.11 in GB50058-92, the wire for power and lights must be copper line over 2.5mm² in diameter. We recommend that the wire should be in accordance with RVV 3x1.5+1x1.5 300/500 (GB50023.3). The switchboard should have reclosers for emergency.
2.
The diameter of the wire entering into the anti-explosive junction box should be consistent with the diameter of the inner hole of the rubber seal. The diameter is about 9mm. After connecting the wire, tighten the bolts to clamp the wire. The metal gasket used with the sealed washer works to press the sealed washer, so it cannot be lost or omitted.
3.
The user connects the power wires through the hole in the anti-explosive switchboard and the three wires should be connected to A, B, and C respectively. If the motor turns in the wrong direction, exchange any two of the three wires. (If the power voltage is 220V, the two wires should be connected to C and N respectively.)
AC380V Three Phase Power Cable Enter JDK50C1111, JDK50C2221 EX-Power Box
AC380V Three Phase Power Cable Enter JDK50D EX-Power Box
AC220V Single Phase Power Cable Enter
After installing the fuel pump, ensure that the power wires are connected correctly, all connections in oil pipes are reliable, and the oil pipe is clean before first supplying power. It is forbidden to examine the fuel pump with water instead of oil.
25
9. MAINTENANCE 1.
The appearance of the fuel dispenser should be orderly and clean, and it should always be waxed. Eliminate the vapour to avoid rusting. In cold regions, the inner parts should be dismantled to clean them and protect them with covers before the winter. All the running parts should be lubricated regularly to ensure that they work well.
2.
The filter mesh of the gear pump should be dismantled and cleaned periodically (each week). It should be replaced if it is damaged. Wash the mesh sheath with gasoline and remove the dirt in the inlet to the pump.
3.
The oil tank should be cleaned periodically (about once a year) to keep the oil pure.
4.
The adjusting screw in the bypass valve of the pump is used to adjust the pressure of the pump and the discharge of the fuel pump can also be adjusted. The screw has already been adjusted before leaving the factory. If the discharge decreases after a long time, adjust the screw to increase the pressure in the pump. However, the pressure must not be too high to avoid destroying the pump or making a loud noise.
5.
Frequently check the pipe line connections, seals, O rings, and sealed gaskets to ensure that there are no leaks. Ensure that the oil-watcher has no bubble, the discharge pipe does not emit oil, the power wire is firmly connected, and the ground wire works well otherwise they should be prepared in time. (Suggested wording – please check) Any problems must be corrected as soon as possible.
6.
The user should personally examine the metric accuracy on schedule. If a metric error occurs, contact the local metric department as soon as possible to adjust it.
7.
There is wire in the hose to conduct the static. Each end is connected to the joint of the hose. Always examine the conductivity of the wire between the nozzle and the fuel pump to avoid the wire being destroyed. If the hose is replaced, draw the wire out of the hose, clean it, and ensure that the wire is connected properly to the nozzle and the fuel pump to ensure that they are working normally.
26
10. FAILURE & SOLUTIONS ELECTRONICS FAILURE
Fuelling without accounting
Motor not working
Not stopping No display on both keyboard and display board No display but keyboard and fuelling work No redisplay after power off
POSSIBLE REASON
1. 2. 1. 2. 3. 4. 1. 2. 1. 2. 3. 1. 3. 1. 2. 3.
Impulser failed Main Board failed SSR relay failed Motor failed Power Board failed No output signal from Electronic Control Unit SSR relay failed Main Board failed Fuse failed Main Board failed Power Board failed Main Board failed Power Board failed Redisplay Key failed Main Board failed Battery not recharged
SOLUTION
Replace with new parts
Replace with new parts
Replace with new parts Replace with new parts Replace with new parts Replace with new parts
MECHANICS FAILURE
Not fuelling on small flow but power is on
POSSIBLE REASON
SOLUTION
1. Great suction; long horizontal pipe; too many knee joints; great leakage; or dirty ventilating nut. 2. The filter is jammed; the ventilating valve is blocked; the solenoid valve does not work; the resistance of flow is great; the returning valve cannot close; or the oil returns to lowpressure space. 3. The pump turns in the wrong direction, or is worn out so that there is little or no vacuum. 4. The sealed gasket of the returning floater is destroyed.
Adjust the location of the tank and examine the pipe; Clean the ventilating nut and prepare or replace the filter and valve; Change the turning direction of the motor, adjust the pressure of the belt, and examine the pump.
27
MECHANICS FAILURE
POSSIBLE REASON
SOLUTION
Metric Error
1. The turning parts of the Adjust the ventilating flow meter are worn, or assembly the piston's Overhaul the fuel dispenser displacement or Examine the ventilating discharging volume valve, the returning valve, increases. the cover of the filter and 2. The distributing valve or the pipe. the piston seal does not work. 3. The seal of the vent valve does not work, or the seal of the suction pipe, the filter cover and the returning valve does not work; so the input of air is so great that the air separator cannot manage it.
The Ventilating pipe spouts oil or ejects oil
1. The returning valve is blocked so the normal pressure space has too much oil. 2. The seal of the returning valve does not work; air is mixed with oil, causing it to foam in the pump and in the normal pressure space. 3. The surface of the oil in the tank is higher than the surface of the oil in the air separator.
Clean and examine the bypass valve
1. The preset pressure of the spring in the bypass valve is too great. 2. The filter is blocked, the suction pipe is too long or the vacuum is too great. 3. The suction pipe leaks or the low-pressure space is too drafty.
Decrease the preset pressure Clean the filter and examine the pipe
The noise is abnormal or too high
28
Clean and examine the returning valve Plug up the vent hole.
11. VANE PUMP INSTALLATION DIAGRAM
JDK50C1111 JDK50C2121
JDK50C2221
29
12. GEAR PUMP INSTALLATION DIAGRAM
JDK50D1111 JDK50D2121
JDK50D2221 JDK50D4241
JDK50D6361
30
13. SUBMERSIBLE PUMP INSTALLATION DIAGRAM
JDK50D1112 JDK50D2122
JDK50D2222 JDK50D4242
JDK50D6362
31
ACCESSORIES ITEM
QTY.
LOCATION
Triangle Flange
1 Pce
Fuel Inlet
Seal
1 Pce
Fuel Inlet
3 Pcs
Fuel Inlet
3 Pcs
Fuel Inlet
3 Pcs
Fuel Inlet
3 Pcs
Fuel Inlet
Bolt Nut Gasket Gasket Spring
SPEC.
GB5781-86 M10 X 50 GB41-86 M10 X 50 GB95-85 10 40Hv GB93-87 10 65Mn
REMARKS
FREE SPARE PARTS (LCF-90 GEAR PUMP & LFM-85 FLOW METER) ITEM
O-Ring O-Ring
SPEC.
GB3452.1-92 30 X 3.55 GB3452.1-92 22 X 3.55 GB3452.1-92 38 X 3.55 GB3452.1-92 68 X 3.55 GB3452.1-92 55 X 3.55 GB3452.1-92 56 X 3.55
1 PRODUCT
2 PRODUCTS
LOCATION
2
4
Joint
2
4
Aluminium Pipe
2
4
2
4
1
2
1
2
Square
92 X 3.5
1
2
Square
105 X 3.5
1
2
Joint of inlet and outlet of Flow Cover of inlet and outlet filler Outlet of gear pump Filter of inlet gear pump Cover of Flow Meter Cover of Flow Meter
Soft Wood
1
2
Wavy Pipe
Fuse
2
4
Electronic Control Unit
O-Ring O-Ring O-Ring O-Ring
32
FREE SPARE PARTS (LFYP-50 VANE PUMP & LMF-65 FLOW METER) ITEM
SPEC.
1 PRODUCT
2 PRODUCTS
LOCATION
Seal
19 X 35 X 10
1
2
Shaft of Pump
O-Ring
1
2
LFYP-50 Pump
O-Ring
GB3452.1-92 84 X 3.55 GB3452.1-92 80 X 3.55
1
2
Cover of Filter
O-Ring
65 X 3.55
1
2
O-Ring
65 X 3.55
1
2
O-Ring
38 X 3.55
2
4
O-Ring
30 X 3.55
2
4
Joint
O-Ring
22 X 3.55
4
8
Aluminium Pipe
Square
92 X 3.5
1
2
Square
105 X 3.5
1
2
Fuse
2
4
Cover of Flow Meter Cover of Flow Meter Electronic Control Unit
Vane
6
12
LFYP-50 Pump
Soft Wood
1
2
Wavy Pipe
Soft Wood
1
2
Filter Holder
33
Cover of By-pass Valve Cover of Out-put Valve Inlet and Outlet of Flow Meter
Eh a d Fu e l Dis pe n s e r s
Operation & Maintenance Handbook
34
1. MAINTENANCE OF FUEL DISPENSER A.
The appearance of the fuel dispenser should be orderly and clean, and it should always be waxed. Eliminate the vapour to avoid rusting. In cold regions, the inner parts should be dismantled to clean and protect them with covers before the winter.
B.
All the running parts should be lubricated frequently to ensure that they work well.
C.
The oil tank should be cleaned periodically (about once a year) to keep the oil pure. The filter mesh of the gear pump should be dismantled and cleaned periodically (weekly). It should be replaced if it is damaged. Wash the mesh sheath with gasoline and remove the dirt in the inlet and outlet holes of the pump.
D.
The user should personally examine the metric accuracy on schedule. If a metric error occurs, contact the local metric department as soon as possible to adjust it.
E.
There is a wire in the hose to conduct the static. Each end is connected to the joint of the hose. Always examine the conductivity of the wire between the nozzle and the fuel pump to check if the wire is damaged. If the hose is replaced, draw the wire out of the hose, clean it, and ensure that it is properly connected to the new nozzle and the fuel pump to ensure that they operate normally.
35
2. POINTS TO NOT FOR MAINTENANCE PERSONNEL A.
When checking and maintaining the dispenser, maintenance personnel must not wear chemical fibre clothing and shoes with metal studs. In order to prevent fires in the petrol station, there should be no naked flames, no smoking is allowed, no using of steel or metal tools, or strong magnetic field products (such as mobile phones). The petrol station's safety instructor must be strictly obeyed when carrying out maintenance work.
B.
When checking and maintaining the dispenser, especially the electrical parts, all power sources must be shut off. No repair work should be done while the power is still on.
C.
When checking and maintaining the mechanical parts of the dispenser, and there is a need to drain off fuel, a container must be used to prevent fuel spillage.
D.
When checking and maintaining the dispenser, be careful not to scratch or damage the surface of any spare parts, tightly sealed parts, or sealed chamber surfaces so as to prevent leakage. Before assembly, make sure that all parts are clean and properly washed to prevent damage.
E.
When maintaining the electrical parts, if any wiring needs to be detached, take note of how these were connected in order to prevent new faults occurring after assembly due to incorrect wiring. (This will be discussed in a later chapter.)
F.
Before repairing the dispenser, the cause of the malfunction must be fully understood and analysed and no parts should be changed until a conclusion has been made.
G.
If after replacement of any parts that may affect the metric accuracy, an accuracy test must be carried out.
36
3. INSTALLATION & ADJUSTMENT OF FUELING DISPENSER Installation and adjustment of the dispenser is part of the petrol station's operation. It directly affects the proper business operation, safety of the petrol station, and the prevention of accidents. A.
Inspection and acceptance upon receiving the dispenser.
1.
Check that all the attached parts and components are in accordance with the manual handbook.
2.
Inspect the inner structure components and parts for any damage or loosening caused during transportation.
B.
Positioning of the Dispenser.
1.
The dispenser should be installed outdoors under shelter. The shelter will prevent the dispenser from direct rainfall and sunlight during all seasons. There must be enough distance between the dispensers and surrounding buildings to ensure smooth entry for big trucks or container trailers.
2.
The dispenser should be installed on a concrete foot-base, to prevent any vehicle hitting the dispenser. When the dispenser is above ground level it also helps to improve the anti-explosion safety features.
3.
To help reduce vibration of the dispenser during fuelling operation and to prolong the lifespan of the machine, the body of the dispenser should be positioned and installed perpendicular to the ground. The base of the machine should be level. Position the dispenser on a concrete base and tighten with bolts and nuts. The concrete base should have holes for the access of oil piping, earth wire, communication wire, and power supply.
C.
Installation of Oil Pipe and Oil Tank.
1.
The dispenser usually uses a 1.5 inch (38mm) galvanized seamless steel pipe. The conducting wire should connect evenly across both ends of the pipe with a flange. Fuel storage tanks and piping must have a good earth connection. The oil pipe should be tested at 0.2Mpa pressure.
2.
Keep the pipe line bends to as few as possible and the level between the dispenser and oil tank must not exceed 60 meters. The distance between the bottom of the oil tank and the perpendicular dispenser's oil inlet hole must not exceed 4 metres as this would weaken the suction. The connections on the oil pipe must be sealed with polyethylene.
3.
The inlet pipe at the bottom of the oil tank must be installed with a 1.5 inch (38mm) one-way valve (double door brass bottom valve). The distance between the valve and the bottom of the tank should be about 10cm. Before installation, the tank and valve should be thoroughly cleaned. Test the bottom valve with oil to ensure a tight seal and to prevent blockage or leakage during oil fuelling operations.
37
4.
If more dispensers are to be installed at one petrol station, each dispenser should have an individual pipeline connection. In situations where two dispensers share the same pipeline, a reverse valve should be installed between them to prevent any interference between the two machines.
5.
If the dispenser is using an above ground tank or high rack tank storage (the bottom of the tank is lower than the height of the dispenser's pump, and the top of the tank is higher than the dispenser's pump) the air vent hole of the combination pump should be blocked off to prevent oil flowing out from the air vent nozzle.
D.
Installation of Electrical Equipment.
1.
The main power supply should be located indoors. Each dispenser must have a separate control switch. One control switch must not be used for two dispensers or other machines.
2.
Wiring must be 3 core (4 core) good oil proved; acid proved multi-cored double layer copper wiring cable. The use of single core or aluminium wire core is strictly forbidden.
3.
The wiring between the power room and dispensers should be concealed in piping. This will prevent vehicles from damaging or exposing the wires. At the bottom of the dispenser where the wire cable connects, an oil proved elbow bending connector should be installed to prevent any fuel oil entering the wire tubing and corroding the wiring. There should be no additional connectors between the power cable and wire connection box to prevent sparking and endangering the petrol station.
4.
User's power supply cable should be connected to the anti-explosive connection box. Please refer to the various dispenser models for instructions on how the wiring should be connected. Where the cable enters the box, screws should be used to tighten it. The cables should be positioned tightly to ensure the good functioning of the anti-explosive connecting box.
5.
The dispenser must have a good general earth wire. Every dispenser must connect with the earth conductor to prevent damage caused by lightening and/or static electricity. Each dispenser should have an individual earth wire with a resistance not greater than 4 ohms and the nozzle against the earth's resistance should not be greater than 10 ohms. When using single phase electrical motors, the cross section of copper cored insulation wire used must not be less than 2.5 sq.mm or the electric motor may not be able to start and will burn out.
E.
Testing and Adjustment of Dispenser.
1.
The use of water to test the dispenser is strictly forbidden. Actual fuel must be used for testing.
2.
Before the first test, do a general check of the dispenser, tightening all bolts and nuts which might have become loose during transportation. In particular check both ends of the hose for any loose connections to prevent fuel oil leakage which could result in a fire. 38
3.
If the flow rate for the dispenser is too high or too low it can be adjusted by turning the adjusting screw on the overflow valve of the oil pump. If, when a new oil pipe is connected the beginning flow is normal but then reduces, clean and wash the pump's filter repeatedly. If this does not help check for other faults that may be the cause.
4.
When doing an electrical installation or maintenance, first turn off the power supply. An Ex Box should be installed according to the requirements and the cover must be closed tightly before the power supply is turned on. Testing of the dispenser with the cover open is strictly prohibited.
F.
Fault Analysis and Maintenance of Oil Piping.
1.
No oil flow or slow oil flow. -
2.
There is sand and metal slag in the piping. When the pump sucks the fuel oil it blocks the filter net of the separator. This will cause the pump to run noisily or stop the flow. The filter net should be cleaned frequently. Serious air leakage in the piping or when two dispenser pumps share a common pipe line. This causes a large amount of air inflow into the pipe making it impossible to create a negative pressure and causing the flow to stop. The signs are non-stop air exhausting, light pump sound, and no oil flow. Check and repair piping, increase pipe line, or install stop valves. If the one-way valve on the pipe is damaged or jammed it will cause the oil pump to stop flowing. (Signs are: no exhausting of air, pump sound is light, and no oil flow.) To rectify the problem the one-way valve must be repaired or replaced. If the level of the fuel oil inside the tank is too low, below the pump's suction range, or is below the level of the bottom valve the flow to the pump will stop. To correct this just top up the oil tank to raise the fuel oil level. If the breathing tube for the oil tank is too low or the air cap is too dirty, this will cause air in-flow problems resulting in no flow or slow flowing fuel oil. Raising the air breathing tube or cleaning the air cap will solve this problem. An air bubble within the pipeline will also cause the oil flow to stop or slow down.
No fuelling but display is counting during fuelling operation -
-
Under certain pressures the rubber hose will expand. When the hose is too long or not up to the required standards, when the fuelling starts the rubber hose will expand. If it over expands it will prevent the fuel from flowing but the counting will continue as normal. To rectify this problem the rubber hose must be replaced. If either the foot valve or pipelines are leaking, during the interim of refuelling, oil level in the separator and pump drops, pipeline reverse the oil back to oil tank (this can be seen by opening the separator's filter cover and removing the filter), when during the next refuelling, due to large amount of air flow in, exceed the capacity which the separate can separate, a portion of air flow into the flow meter, pushing and rotate the flow meter and count, the characteristic point is, longer the intermission time, value counted will be greater, causing flow rate various during refuelling, inaccurate counting. To rectify, check the foot valve and oil pipeline and top up the oil tank. 39
4. FUEL DISPENSER CONSTRUCTION & WORKING PRINCIPLE Section 1: Construction of Fuel Dispenser
Our series of dispensers have full function, high metric accuracy, easy handling, and convenient maintenance. The dispenser's external framework is made from high quality steel materials. This is characterised by its unique design and novel appearance. Our dispenser mainly consists of an Ex Motor, oil pump, flow meter, ex impulse sensor unit, ex solenoid valve, ex power connecting box, oil indicator, nozzle, and computer units (if using a submersible pump there is no anti-explosive requirement for the electric motor and pump). Functions are as follows:
1.
The Ex Motor is the driving power of the dispenser. Under the control of the computer setup it converts electrical energy into mechanical energy.
2.
The Oil pump (LFYP-50 Vane Pump, LFCP-90 Gear Pump) is driven by the Ex Motor. It will suck the fuel from the oil tank, flow through the pump, and into the flow meter, with a constant pressure and volume. In the meantime it will separate the air from the fuel oil and dispose of it into the atmosphere.
3.
A Flow Meter calculates the volume of the fuel oil flowing through it and converts this volume into the rotating shaft's angular displacement unit.
4.
Ex Impulse Sensor: The flow meter's rotating shaft drives the shaft of the impulse sensor at the same time. It will convert the flow meter's rotating shaft's angular replacement unit into an impulse signal using a photo-electric converter. The impulse signal will be sent to the computer for processing and display.
5.
The Ex Solenoid valve is a device meant for improving accuracy during preset fuelling.
6.
The power source is safely imported to the dispenser via the Ex Power Box.
7.
The Oil Indicator is used to check that there are no air bubbles in the flow of fuel oil. It is a device for the user to check the fuel oil quality.
8.
The Nozzle is meant to guarantee safe fuelling operations.
9.
The Computer Unit is a small system which runs all the dispenser's required programme software applications. It has the ability to process and calculate, display and control. It has a communication function and is the control centre for the entire electronic sector.
40
JDK50C1111 One Product One Nozzle Fuel Dispenser
CONSTRUCTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
JDK50D1111 One Product One Nozzle Fuel Dispenser
CONSTRUCTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
Electronic Control Unit Main Body Solenoid Valve Ex Impulse Sensor LFM-65 Flow Meter LFCP-90 Gear Pump Ex Power Box Flexible Hose and Flange Ex Motor Key Board Nozzle Holder Nozzle Fuel Indicator Name Plate Hose
41
Keyboard Nozzle Holder Nozzle Fuel Indicator Hose Nameplate Display Board Ex Impulse Sensor Solenoid Valve LFM-65 Flow Meter LFYP-50 Vane Pump Ex Power Box Ex Motor Flexible Pipe and Flange Main Body
JDK50D1112 One Product One Nozzle Submersible Pump Fuel Dispenser
CONSTRUCTION 1&2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
Main Body Electronic Control Unit Key Board Solenoid Valve Flow Meter Ex Power Box Filter Flexible Hose Flange Nameplate Nozzle Holder Nozzle
Section 2: Working Principle of Fuel dispenser
Drawing the nozzle or pressing the Fuelling/Unit Price Key, will trigger the computer unit to send out a “start fuelling” command signal. It will activate both the Ex Motor and solenoid valve and will reset the display to zero. Gear pump when driven. The Ex Motor pumps up the fuel from the oil tank. Compress and separate the air from the fuel. Air is vented into the atmosphere and pure fuel oil, under pressure, will flow into the flow meter. Fuel oil flowing through the flow meter pushes the 4 pistons, creating motion and turning the rotating shaft. A large amount of fuel oil passes through the solenoid valve, oil indicator, and hose and into the vehicle's petrol tank. The rotating shaft of the flow meter will cause the cutting notch disk of the impulse sensor to rotate. A photo-electric converter will convert the angular replacement unit of the flow meter's rotating shaft into an impulse signal, which is then sent to the computer for processing and display. Replacing the nozzle into the nozzle holder or pressing the Halt key on the keyboard will trigger the computer unit to send out a “shut-off” command signal to the Ex Motor, thus ending the refuelling process. For preset refuelling, first input the preset amount. When the fuelling nears the preset amount, the computer unit will first shut down the solenoid valve's main valve. The dispenser will continue fuelling at a lesser volume and once the preset amount is reached the computer unit will shut off the solenoid valve's sub-valve and Ex Motor to end the fuelling process. 42
Principle
Starting the motor, and the motor drives a pump to pump fuel from a tank through pipe and flexible pipe into the filter of the pump. After filtering, the fuel is compressed and then pumped into the air separator, built into the pump, which separates gas from the fuel, and the gas is discharged outside at the same time. The compressed fuel moves the four pistons. When the four pistons have completed a cycle, a specific amount of fuel is transmitted, and simultaneously the shaft drives the impulse to rotate, encode and output the digital pulse. The electronic control unit receives the digital pulse, accounts, stores, and displays all the data involved. The fuel goes through the fuel indicator, the nozzle, and into the tank of a vehicle.
Principle Diagram of JDK50 Fuelling Dispenser
Power Supply
Display
Key Board
Ex-Power Box
Electronic Control Unit
SSR Relay
Ex-Impulse Sensor
Ex-Motor
Flow Meter
Solenoid Valve
Oil Pump
Tank
Nozzle
Discharger Gas
Direction of Current Signal & Mechanical Movement....... Direction of Fuel..........................................................
43
Fuel Container
5. GEAR & VANE PUMP CONSTRUCTION & WORKING PRINCIPLE Section1: Construction of Pump
The main section of the fuel dispenser is a hydraulic system. Its mechanical power source is the Ex Motor, which can convert electrical energy into mechanical energy. The fuel pump converts the mechanical energy into hydraulic energy. The Fuel pump's performance directly affects the dispenser's ability to pump and dispense. At present, our pumps consist mainly of a Vane Pump (model LFYP-50), Combination Gear pump (model LFCP-90), and Combination Gear Pump (model LFTP-80 | combination oil pump and air separator). Specific construction structure shown in the diagram below:
Exploded View of LFYP-50 Combination Vane Pump
1. 2. 3. 4. 5. 6. 7. 8. 9.
Pulley Wheel Pump Assembly Oil Seal 19 x 35 x 8 Pump Cover Assembly Rotor Assembly Vane Blade Pressure Adjusting Assembly Overflow Valve Cover O-ring 65 x 3.5
10. Outlet Valve Cover 11. O-ring 65 x 3.5 12. Outlet Valve Spring. 13. Rotary Oil flow Valve Assembly 14. Rotary Oil flow Valve Assembly 15. Connecting Box 16. Seal Gasket 17. Pump Assembly Cover 18. Screws
44
19: Float Assembly 20. Seal Gasket 21. Seal Gasket 22. Pump Body Assembly 23. Oil Filter Assembly 24. Oil Filter Spring 25. O-ring 80 x 3.5 26 Oil Filter Cover
The vane pump components and filter, overflow valve, and discharge valve, which are tightly assembled inside the pump body, are together called the Pump Assembly. The Vane pump component is a combination of stator parts assembly, and rotor parts assembly. The stator parts assembly consists of an eccentric sleeve, shaft sleeve, and covers on both ends. There are two oval-shaped window holes in the middle section of the stator part assembly. The right window connects with the inlet hole, return oil hole of the overflow valve, and return oil hole of the return valve in the normal pressure chamber. We have named this space the low pressure chamber. The left window leads to the oil separator tube; this space is named the high pressure chamber. The Rotor part assembly is made up of the rotor shaft and rotor assembly. There are six equidistant vane grooves along the circumference of the rotor assembly. Vane blades have a forward/back movement within the grooves towards the centre point of the rotor assembly. There is an eccentric distance between the rotor assembly and the centre of the eccentric sleeve, circumference of the rotor assembly, and inner circumference of the stator assembly, inter-cutting at point K (fig 6). The height of the rotor with the vane blade and the inner height of the stator assembly are the same. When the rotor rotates, the vane blade will tightly in contact with the inner wall due to the centrifugal force. It also has a forward/back motion within the grooves toward the centre point of the rotor assembly. The inner chamber of the stator assembly can split into four sectors using the vertical centre point as a guideline. It can divide into upper and lower tightly sealed zones and left and right transition zones. The angle between the two vane blades on the rotor is 60 degrees thus in the two tightly sealed zones there will be one or two vane blades isolating the transition zone and preventing the oil within the two inner ends of the chamber from flowing. However, the oil within the transition zones are linked. When the rotor rotates in a clockwise direction (observed from the direction of the pump cover), it will have an effect on the suction and compression of the oil fluid, helped by the effect of dimensional changes in the two transition zones, as illustrated in Fig. 7. With the centre vertical line as a guideline, the position of blades A & B at the bottom of the rotor is symmetrical. When the rotor rotates clockwise over a distance of 60 degrees, blade B will move from its previous position to where blade A was. Oil fluid between the blades moves from the centre position towards the left chamber. The right chamber now needs to be refilled with oil fluid toward the centre position. The tightly sealed zone now becomes bigger creating a partial vacuum. Under the effect of atmospheric pressure the oil fluid in the oil tank is sucked through the pipeline into the pump's inlet hole. In the meantime the left chamber's sealed zone becomes smaller. Oil fluid is squeezed out through the discharge valve. When the rotor continuously rotates, oil fluid forms a definite pressure and flow rate. Strength of operating pressure depends on the adjustment of the overflow valve and its load resistance. Pressurised oil fluid flows from the high pressure chamber into the air separator tube. Some of the oil fluid flows back to the low pressure chamber through the overflow valve and the rest flows through the discharge valve into the flow meter. When the nozzle is activated, the load resistance will be lower and pressurised oil fluid overcomes the tension of the spring of the outlet valve and flows through the discharge valve into the flow meter. The overflow valve is in the shut-off mode or slightly open. When the nozzle is shut off, the oil pressure increases. The core of the overflow valve overcomes the tension of the spring and moves towards the side of the spring with the aid of the fluid pressure. Pressurised oil fluid in the high pressure chamber flows to the low pressure chamber through the overflow valve, repeating the cycle. Turning the adjusting screw on the overflow valve will change the tension of the spring. This will adjust the pressure of the hydraulic system and the flow rate. Turning the screw clockwise will compress 45
the spring increasing the amount of pressure needed to push the valve open. All of the oil fluid, or the majority of it, will flow through the outlet hole and the outlet flow rate is increased. Turning the screw anti-clockwise will loosen the spring decreasing the amount of pressure needed to open the vale. A portion of the oil fluid will overflow overflow back to the low pressure chamber and the outlet flow rate is reduced.
Pump Zoning Diagram
Working State Diagram
The principle of the air separator is to t o separate the air vapour from the oil fluid and discharge it out from the pump body. body. The pump housing is made of die cast aluminium aluminium together with the oil pump assembly. assembly. Internally it is divided into three chambers. One chamber, chamber, where the filter net is located, is the low pressure chamber. chamber. Below its inlet hole, it connects with the flexible pipe. The chamber with the rotating air separator connection is the high pressure chamber. chamber. One side of the lower part of the rotating air separator tube is linked with the discharging hole and the other side with the discharge discharge hole behind the discharge discharge valve. In between the two is a hole with a 4mm. The floater is is located in the normal pressure chamber, chamber, which is linked to the outside through the vent hole (Fig. 8). When the oil pump discharges pressurised oil fluid through the discharge hole into the rotating air separator tube, the majority of the oil fluid will move along the spiral groove on the tube wall towards the discharge valve. valve. The density of the air vapour inside the oil fluid is lower than the density of the oil o il fluid and will therefore gather in the centre of the tube chamber and discharge out from the 4mm hole on the right side together with a quantity of oil fluid into into the normal pressure chamber. chamber. When the mixture of air vapour and oil fluid enters the normal chamber, chamber, the air vapour will rise and discharge out through the vent hole. The oil fluid remains remains in the chamber. chamber. When it has accumulated to a certain level the float will rise, moving the connecting lever and opening up the return valve. Oil fluid will flow back to the low pressure chamber through the return valve. When the fluid surface drops to a certain height, the gravity effect will lower the float shutting off the return valve and ending the process of returning oil. Combination Vane Pump Operating Principle Diagram:
46
LFCP-90 Combination Gear Pump Components & Structure:
The type of pump shown below is a combination gear pump assembly and air separator assembly, assembly, with compact, light and reliable aluminium alloy housing. 1. Pulley 2. Bearing 3. Bea Bearing ring Gas Gasket ket 4. Busing 5. Slid Slidin ingg Be Bearin aringg 6. Anti Anti-s -ski kidd Bush Bushin ingg 7. Spring 8. Inner Ge Gear 9. Outer Gear 10. O-Ring 11. Pump Cover 12. Cover 13. Seal Gasket 14. Pole 15. Filter Assembly 16. Nut 17. Overflow Valve 18. Seal Gasket 19. Union Joint 20. Seal Gasket 21. Screw 22. Nut 23. Pump Body 24. O-ring
25. O-ring 26, Filter Assembly 27. Upper Cover 28. Valve Assembly 29. Seal Gasket 30. Pipe 31. Seal Gasket
32. Float Seat 33. Float Assembly 34. Seal Gasket 35. O-ring 36. Plug 37. Seal Gasket 38. Seal Gasket
39. Float Seat 40. Float 41. Seal Gasket 42. Vent Joint 43. Vent Nut
Working Principle:
The inner and outer gears rotate in a clockwise direction, forming a low and high pressure chamber inside the chamber, chamber, and completing the process of suction and compression of oil o il fluid.
The overflow valve consists mainly of a valve seat, valve core, spring and adjustable screw. Under normal conditions the high and low pressure chambers are separated. When the nozzle is shut off o ff or the refuelling process is obstructed, pressure in the high pressure chamber rises rises pushing the valve core towards the right. This causes the oil fluid fluid to flow from the high pressure chamber to the low pressure chamber thus controlling the pressure p ressure of the oil fluid and making the oil fluid recycle within the pump. The operating pressure of the oil can be achieved by adjusting the spring of the overflow valve. When the nozzle is shut off o ff,, oil fluid recycles within the pump. There are two filter nets nets in the pump (filter nets are marked with STAINER STAINER marking). These are the inlet and discharge discharge filters. The filters must be cleaned periodically to ensure a good flow. 47
Section 2: Oil Pump Operation & Maintenance
Always check and maintain the oil pump during the operating process. 1.
Regularly check the fluency of the oil pump's rotation. Check if there is any unusual noise. Check the gasket seal of the pump housing and see if there is any leakage of oil fluid. Check the driving belt to see if it slips or vibrates.
2.
During the testing of the dispenser, or when cleaning the oil tanks, do not use the dispenser to pump water or any fluid that contains water. This is to prevent the pump and its assembly parts from becoming rusty or freezing and cracking in low temperatures.
3.
The filter nets inside the pump should always be cleaned (LFCP-90 Gear pump consists of an inlet filter and discharge filter), especially in newly installed machines and pipelines. After a long period of use the dirt within the oil tanks and pipelines will be reduce, duration for cleaning the filter nets can extend suitably but usually not more than a month. It is strictly forbidden to use the dispenser for fuelling or testing when there are no filters in the pump to prevent any debris entering the pump or flow meter, which would cause jamming or scratching of the inner wall of the flow meter reducing the life span of the flow meter.
4.
Due to a long period of usage the drive belt may lose its tension and slip causing inconsistent fuelling or no oil flows at all. It should be suitably adjusted and if the belt is badly damaged, it should be replaced immediately. The belt must also not be too tight as this would increase the load on the Ex Motor shaft and the pump, increase the speed of, or wear out, the Ex Motor's shaft, pump shaft, and oil seal.
5.
The overflow valve spring must not be adjusted too tight. It will increase the pressure of the pump system resulting in loud noise, an increase in the vibration, and speed up the wearing out of the pump shaft.
6.
Check the air vent tube regularly to ensure that there is no oil flowing out of the tube or that it is sucking in air.
7.
Check regularly if there is any leakage on the pump housing or any loosening of any fixed screws.
Section 3: Oil Pump Fault Analysis for Oil Pump
Before any maintenance or repair work is carried out, you must first accurately determine the faults and understand and analyse the phenomenon of the faults. Common faults for pumps are: No oil supply; insufficient supply of oil; leaks; loud noise and abnormal increase in vibration; fluid and air not separated; oil fluid flowing out through air vent, etc. Below is an analysis of these faults and ways to remedy them.
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A.
No oil flow or insufficient oil supply
Other than the pump faults, components and parts such as pipelines, flow meter, impulse sensor, solenoid valve, rubber hose and nozzle can also cause problems of either no flow or insufficient flow. The main reason for this is due to negative pressure that cannot meet the requirements. The degree of vacuum at the inlet hole must not be less than 60kPa, to ensure that the vertical height of the suction path reaches 4 metres and the horizontal level path, 60 metres. If the inlet hole has less than a 40kPa degree a vacuum (insufficient negative pressure), then non-suction of oil fluid will occur. Any leakage in the pump will also cause insufficient negative pressure. If the cutting clearance between the rotor parts and stator parts of the vane pump are too big the clearance between the side of the rotor part and the cover will be too big (for the gear pump this is the clearance between the outer gear and cover) If the overflow valve is not tightly sealed or the valve core is stuck this will also cause large leakage within the pump. Another reason for negative pressure dropping below the level of requirement is if the floater seat was not sealed tightly causing air from outside to enter the oil pump. 1.
No oil flow or insufficient oil supply. Check and rectify as follows (also refer to troubleshooting chart).
First check the external factor. Check if the Ex Motor is turning or not; if it rotates in the wrong direction or the rotating speed is too slow; or the drive belt is slipping. If the rotating speed is too low first check the voltage of the external electric supply source to see if it is normal, also if the Ex Motor or the silicon controlled is damaged. If the above are functioning properly, check the filter assembly cover and the gasket seal connection of the flexible pipe to ensure that there are no leaks. Also check that the filter is not too dirty and for any suction effect on the air vent. If a leakage problem is seen, re-install and tighten the cover, flexible pipe connecting joint, and/or replace the relevant parts. Clean and/or change the oil filter net (there are two – inlet filter and discharge filter in a gear pump), tighten the valve core seat and or replace the float assembly parts. If the fault has still not been found check whether there is a foreign object jamming the overflow valve, that the valve seat is tight, and that the discharge valve is not rusty and unable to open. Clean the necessary parts, and reassemble or replace the relevant parts. If these actions have still not resolved the problem then it can be determined that the vane blade may be severely worn out or damaged. Dismantle the pump and check the degree of wear on the vane blade, rotor and stator parts. If the vane blade is severely damaged or broken, replace it (for the gear pump check if the inner gear and the bushing are badly damaged).
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B.
Leakage
There are two types of leakage; internal and external. An internal leak refers to fluid within the hydraulic system flowing from the high pressure chamber to the low pressure chamber due to differential pressure. A worn vane blade (inner gear of gear pump worn out) will increase the leakage thus reducing the output flow volume. Pump Flow Troubleshooting Chart
No oil flow or insufficient oil supply Ex Motor not turning or turning n the wrong direction.
Yes
Check for electric source fault.
Drive belt slips or Rotors in the vane pump are jammed. (Gears jammed).
Yes
Tighten the driving belt or remove foreign object in the pump and/or replace rotor parts.
Check the filter assembly cover and the connection seal gasket on the flexible pipe to see if there are any leaks, if the filter net is too dirty, or if there is a suction effect on the air vent.
Yes
Tighten or replace relevant parts; clean the filter net; tighten the valve core and valve seat and/or replace the float assembly.
Overflow valve core is jammed and cannot close tightly or the valve seat has loosened.
Yes
Remove foreign object and reassemble.
Discharge valve is jammed and cannot open.
Yes
Clean it or replace it.
Vane blade has worn out or broken. (Gear of gear pump is severely worn).
Yes
Replace vane blade or rotor parts. (Replace the inner/outer gears).
External leakage refers to oil fluid leaking from inside the system to the outside. External leakage not only affects the function of the pump, but also endangers the surrounding environment. If the external root of the protruding shaft leaks externally the oil seal should be replaced. During the installation take note that the oil seal is installed the right way. In addition ascertain why the oil seal failed; has the overflow valve been adjusted too tightly, is the tension of the belt too tight. After prolonged use seals may deteriorate due to normal wear and tear. This must be monitored regularly, as all o-rings and seals must replaced before leakage or damage occurs. 51
C.
Loud noise and unusual vibration
There are many reasons for loud noise and unusual vibration. It could be caused by the dispenser itself or from some other source such as the horizontal level distance between the underground oil tank and the dispenser being too great, or too many angle bends when installing the pipelines. Other causes could be if the pipes were not cleaned on the inside, the opening of the bottom valve is too small, the diameter of the pipelines are too small, or the quality of the fuel oil is bad, etc. All these will cause loud noise and unusual vibration of the dispenser during refuelling operations. When a loud noise and vibration occurs first eliminate all the external reasons and factors and then proceed to check the dispenser itself for the cause. The following can be the reason for the dispenser to be the cause of the fault:
The filter net is too dirty. A dirty filter net will cause insufficient inflow of oil to the oil pump causing loud noise and an increase in vibration. Dismantle and clean the filter nets (Gear pump consists of an inlet filter and discharge filter).
Check the spring on the overflow valve to see that it is not too tightly adjusted or jammed by an object. Clean the overflow valve and remove any obstruction. Do not adjust the spring too tightly, just sufficient for a high flow volume, as this will raise the pressure load on the pump causing an increase in the noise and vibration, and shortening the lifespan of the pump.
If the problem still persists, check whether the cutting clearance between the rotor parts and stator parts is too small (less than 0.02mm) or if there is no clearance at all. Check if the clearance between the side of the rotor shaft and the front cover is too small (less than 0.02mm) and the clearance between the rotor shaft and the cover for the bearing holes on both ends of the shaft is too big (clearance should be 0.035-0.05mm). Check both surfaces of the vane blades (the face which is in contact with the vane grooves) if there is a big difference in their degree of level. Big differences between the degree of level of the vane grooves, a broken vane blade, or if a vane blade has become jammed, will also cause the combination vane pump to produce a loud noise and vibration during the operating process. The solution is to polish he vane blades and groove surface and replace any parts if necessary. In the combination gear pumps consider whether the clearance between the cutting point of the inner and outer gear is too small, or the clearance between the inner and outer gear with the inner face cover is too small, or the inner gear's shaft bush has too much clearance due to serious friction. Also if the screws for the cover are not tightened, this will cause stress on the inner gear and will result in the problem of loud noise and vibration.
A synchronised vibration is also one of the causes of loud noise and vibration. This occurs when the vibration frequency of the Ex Motor, and fuel pump are close to the vibration frequency of the pressurised fuel oil within the oil pipelines and the normal vibration frequency of the dispenser. This cause can be checked whilst the dispenser is in operation by touching the different parts of the dispenser. If there is an obvious reduction of noise or vibration when touching certain parts then it can be assumed that the problem is synchronized vibration. The solution is to add additional shock absorbing rubber sheets between the attachment of the Ex Motor and the frame, as well as
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between the fuel pump and frame. An air bubble in the rubber hose will also cause the dispenser to be noisier and will also cause irregular flow rates.
D.
Certain fuel oil products have a poor lubricating nature. When a new dispenser uses this type of fuel oil product it will create greater friction causing loud noise. This is a normal situation and as the friction reduces over time the noise will diminish. Oil and air cannot be separated.
This is mainly due to a large amount of air bubbles in the fuel oil products inside the indicator and hose. There are a number of reasons why the air vapour cannot be separated from the oil such as the connecting coupling at the flexible pipe, and the pipelines and valves beneath the flexible pipe, are not tightly sealed. These all have the potential for allowing in large amounts of air when the air being sucked in exceeds the limits that the air separator can handle. This causes the problem of oil and air that cannot be separated. How to check:
E.
Check all the pipelines between the storage tanks and dispensers to see if there are any leaks. To check, open the filter cover of the pump. Look for any oil fluid inside the low pressure space. If there is no oil then top up with oil. If the level of the oil fluid is still decent gradually after top up, we can conclude that either the pipelines or valves below are leaking. Check if the low pressure space has an oil leak, if the filter cover is tightly sealed, if the flexible hose joint is properly tightened, and if the return valve is tightly closed (place your finger near the air vent to see if it is sucking air). All these will cause a small amount of air to enter preventing the oil and air from being separated. The solution is to tighten all the necessary connecting seals or to clean the return valve and/or replace the float assembly parts. If the problem persists then check that the high pressure passage pipe inside the vane pump is not faulty. This could be that the flow deflector has shifted out of position causing the wrong output direction of the pump. Alternately the air hole on the pipe may be too small or is blocked. This can be solved by reassembling the flow deflector and/or replacing it. Enlarge the air hole or replace the high pressure passage pipe (in a combination gear pump, this problem will be caused if the air hole on the oil passage is too small or is blocked). If after checking all the above the fault has still not being found, then it is possible that the discharge valve is the cause. If the discharge valve is jammed by a foreign object and cannot close tightly, air will enter through the discharge valve into the flow meter together with the oil fluid resulting in the air and oil not being separated. To resolve this dismantle and clean the discharge valve. Remove all dirt or foreign objects and reinstall. Fuel oil flowing out from air vent
When the level of oil fluid in the storage tank is higher than the height of the air separator it can cause the oil to flow out from the air vent tube. When this happens, first check if the storage tanks used in the petrol station are high-rack or semi-rack (half the tank above ground and half underground) tanks. If they are high-rack and semi-rack tanks the air vent outlet may be blocked. NOTE: if the level of fluid inside the semi-rack tank is lower than the dispenser, the blocking of the air vent outlet may cause the air/oil separation fault. If the storage is 53
underground follow the steps below to check and maintain: Check to see if the return oil floater assembly can float. If the floater assembly is damaged or the lever arm is broken etc it may prevent the return valve from opening.
If the level of fluid in the high-pressure chamber rises it will flow out through the air vent. The solution is to clean the return valve and repair or replace the floater assembly. Check if the air hole on the high-pressure passage pipe is too big. Too big an air hole will cause most of the oil fluid to flow directly into the high pressure chamber where it will be unable to flow back to the lower pressure chamber, through the return valve, in time. This will result in the fluid flowing out through the air vent. Check the high-pressure pipe inside the pump to ensure that the connections are tight and that there are no oil leaks (for the combination gear pump, the floater seat sealing gasket is damaged). This causes large amounts of oil fluid to flood the atmospheric pressure chamber. The return valve has insufficient time to allow the oil fluid to flow back to the low pressure chamber and instead it flows out through the air vent. The solution is to replace the sealing gasket and any other relevant parts.
Section 4: Things to Note during Dismantling and Assembly of Oil Pumps
1.
All electrical supply must be switched off before servicing. Remove the drive belt from the pulley and position the oil container to prevent oil fluid from spilling onto the ground.
2.
Before assembling the oil pump, make sure that all the parts and the body are properly cleaned. There must not be any dirt on any of the parts in order to prevent scratching the oil pump and causing new problems.
3.
During assembly of the oil pump, carefully check every seal gasket and seal ring for damages. Ensure that these are correctly installed to prevent any possible leakage.
4.
During the assembly of the oil pump, when tightening the screws, follow the order of opposite angle tightening at different times. The amount of tightness must be appropriate, especially during the assembly of the gear pump cover. If the cover is tightened too much it will jam the gears. If it is too loose then the degree of vacuum for the pump will not be achieved.
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6. FLOW METER CONSTRUCTION & WORKING THEORY Section 1: Structures and Working Theory of Flow Meter
The function of a flow meter is to measure the volume of the output of oil fluid. The basic and most important guideline for a flow meter is the accuracy of measurement. Flow meters used in dispensers are volume type flow meters. That means whenever a fixed volume of fluid is passed through, the rotating shaft of the flow meter will produce a definite angular displacement, and correspondingly, the impulse sensor will output a definite quantity of pulse signal. Common types of flow meters are a metal piston type, and a leather cup piston type. A.
Structure of a Flow Meter
Presently, the flow meters which the Lanfeng dispenser uses are the leather cup piston type. There are models such as LFM-85, LFM-70, LFM-65, LFM-473, and LFM-220 (vane blade). Construction of flow meters is as per the diagram below. Different flow meters have different discharge fluid volumes per working cycle (LFM-65 and LFM-85 are the same) but the construction and working theory are similar. For your reference our hand book is based on analysing the construction and working theory for flow meter model LFM-65. The flow meter consists of a top cover, body, bottom cover, side cover, piston assembly, connecting rod, crank shaft, distribution valve, valve seat, etc. There are four cylinder chambers with stainless steel bushings within the body. There is a passage below every cylinder chamber. Pressurised oil from the pump flows from this passage into the cylinder chambers and flows out from this passage again after measuring the volume. The piston assembly consists of a piston, piston rod and leather cup assembly. All four piston assemblies are interchangeable. The cross bolt at the bottom end of the rotating shaft is connected to the distribution valve and the top part of the shaft is connected to the impulse sensor with a cross pin. B.
Working Theory of a Flow Meter
Pressurised fluid from the oil pump flows to the flow meter through an inlet hole and reaches the outside hole of the distribution valve. It flows into one of the piston chambers through the passage ways above the piston chambers, pushing the piston inside and starts a piston motion, also by means of connecting rod, it will push the piston motion of the opposite piston chamber thus pushing the oil fluid through the passage above the piston chamber, inside hole of distribution valve and into inner chamber of flow meter. Oil fluid entering the inner chamber will flow through the outlet hole at the side of the bottom cover and discharge out. The piston motion will also cause the crank shaft to rotate. The cross bolt on the crank shaft will drive the distribution valve and the cross pin on top of the crank shaft will drive the impulse sensor. When the distribution valve rotates to a definite angle, the other pair of cylinder chambers will have an inflow and outflow of oil fluid. All four pistons will complete one working cycle due to the pushing of pressurised oil fluid. When the crank shaft completes one rotating cycle it discharges a fixed volume of 0.5 litres of oil fluid. Relatively when the impulse sensor rotates one cycle, it will send out a definite pulse signal
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LFM-65 Flow Meter Diagram
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19, 20. 21. 22. C.
Bottom Cover Steel Ball Sleeve of Crank Crank Assembly Bottom Cover Seal Body Side Cover Seal Side Cover Back Cover Assembly Sleeve Connecting Lever Hexagon bolt Crank Gasket Distributor Valve Seat Top Cover Seal Ring Bolt Gasket Screw Gasket Gasket of Distributor Valve Spring Upper Cover
Accuracy adjustment of a flow meter
All the dispensers are calibrated for accuracy at our factory before delivery. This is sufficient to fulfil the accuracy requirement but when used over a long period, due to machine attrition, there will be a deviation between the actual volume discharged and the theoretically discharged volume. The accuracy of the flow meter will be lower and it will be necessary to adjust and calibrate the flow meter again in order to meet the accuracy requirement. Methods of adjustment and calibration:
First remove the locking pin from the adjusting hand wheel. Turn the wheel clockwise. This will move the adjusting screw inwards and will reduce the discharge volume. Adjusting a one hole distance will adjust the accuracy by 0.1%. Adjustments can be made at one hole or half hole distance. When adjustments are complete replace the locking pin and seal with lead (adjusting operation must be authorised by the relevant local authority). D.
Comparison of leather cup piston type flow meters and metal piston type flow meters.
Leather cup piston type flow meters are smaller in volume and lighter in weight. The four piston assembly and connecting rods of the leather cup piston type flow meter are interchangeable and easy to dismantle and assembly. 56
Rolled stainless steel is used for cylinder bushes as this has a good resistance against corrosion. When using leather cup type piston it has a better protection for the piston chamber and it is easy to replace the pistons.
It is not sensitive to the quality of fuel oil used and will not result in a flow meter jamming due to rusty parts. The adjusting wheel can be used to adjust and calibrate the accuracy of the flow meters and is easy to operate.
Section 2: Faults and Maintenance of Flow Meter A.
No flow or small flow amount
No flow, or small flow amount, is mainly caused by jammed or inconsistent rotation. More often it is due to jamming, e.g. the steel ball on the bottom cover is rusty; the crankshaft is damaged; positioning screws on the pistons have become loose; using of bad quality fuel oil containing dirt and causing the piston to jam. The solution is to dismantle the flow meter, fasten all loose parts and screws, replace damaged parts and reassemble. B.
Deviation of measurement
The cause of a deviation of measurement, other than the flow meter itself, can be due to the impulse sensor and main computer board. First check if the impulse sensor and main board have any errors. This can be done by dismantling the impulse sensor from the flow meter (when the dispenser is in operating mode, the nozzle is shut off). Turn the shaft of the impulse sensor to see if the computer display indicates 0.5 after one full turn (The display value is due to the discharged amount of one working cycle). Try turning more rounds for better results. If the value is less than 0.5L first eliminate faults with any electrical parts (this will be explained in a later chapter). If the value is 0.5L then consider that this is the fault of the flow meter. The procedure for checking and repairing are as follows:
First check that there is no leakage in the flow meter. If a leakage is found, replace the necessary seals. If there is no leakage check the oil indicator to see if there are any air bubbles inside (this was mentioned earlier) If no fault is detected after checking as above, adjust the accuracy by adjusting the hand wheel. A long period of usage will cause attrition of the flow meter resulting in a deviation of accuracy. This can be adjusted by turning the adjusting hand wheel until the accuracy requirement is achieved. During adjustment, do not adjust too many hole distances at one turn as this might cause damage to the flow meter. If the accuracy cannot be set to the requirement, the top and side covers must be opened. Check if the leather cup is damaged and that the surface of the distributor valve is not scratched. Hard particles in the oil fluid might have torn the leather cup or scratched the surface of the distributor valve. All this will increase the inner leakage and reduce the accuracy of measurement. When this situation occurs replace the leather cup and/or sand the surface of the distributor valve. The following situation may occur during refuelling. When the motor is running the 57
nozzle has a small amount of flow but the rotating shaft of the flow meter is not moving and the computer doesn't display the flow amount. This phenomenon is mainly caused by inner leakage of the flow meter. LFM-220 Flow Meter Exploded View 13
12 11 10 9
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
8 7 6 5 4 3 2 1
Oil Seal Cover Po; Sea; 6 x 19 x 6 Screw M6 x 16 Front Cover O-Ring 124 x 3.1 Washer Spring Gasket Ring Bearing 6901 Vane Blade Rotor Assembly Push rod Body Back Cover
Components structure:
Main parts are made from low-pressure moulded aluminium alloy, and have a good stable nature. The rotor assembly rotates directly without other shaft. Working theory LFM-220 Flow Meter:
Model LFM-220 is a flow meter with a large discharge volume. The electric motor drives the oil pump. Under the effect of the pump pressure, the rotor with the vane blades turns discharging a definite amount of oil fluid and turning the drive shaft. Working Theory for LFM-85 Flow Meter:
The main parts are made from stainless steel and advanced industrial plastic material, and are anti-corrosive, highly wearable and sealed. The drive shaft is a “push and pull” drive made up of a connecting lever and a crank. It has no intermission, no concussion and no abnormal sound. When the drive shaft rotates, it also drives the sensor shaft producing the impulse signal that is transmitted to the computer. 58
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50.
Retaining Ring External Transmitting Bushing Gasket Gasket Transmitting Shaft Dowel Pin Bolt Spring Washer Gasket Seal Rink Lip Seal Seal Cover Gasket Chamfer Head Screw Spring Sasher Retaining Pin Spring Distribution Valve Nut Bolt Spring Washer Gasket Distribution Valve Base Gasket Bushing Pin Gasket Gasket Crank shaft Retaining Ring External Gasket Rolling Wheel Steel Ball Bushing Seal Ring Press Cover End Cover Seal ring Housing Pin Adjustment Wheel Positioning Pin Nut Piston Plate Leather Bowl Press Board Gasket Connecting rod Upper Cover Md-212 Sensor
LFM-85 Flow Meter Exploded View
59
An adjustment hand wheel can be used to correct the accuracy when necessary. When turning clockwise, the delivery capacity will be reduced; when turning anti-clockwise, the delivery capacity will be increased. It is easy, accurate and stable. The meter can be adjusted one hole at a time. It can also be adjusted a half-hole distance. A one hole distance is about 0.05%. After adjustment, insert the lock pin and seal with lead (adjusting operation must be authorised by the relevant local authority). When the high pressure fuel flows through the meter, it drives the four pistons to complete an operating cycle. When the crankshaft turns on full rotation the volume of fuel discharged by an operating cycle is 0.5L (See Fig.13). Working Theory for LFM-473 Flow Meter:
The main parts are made from stainless steel and advanced industrial plastic material, and are anti-corrosive, highly wearable and sealed. The drive shaft is a “push and pull” drive made up of a connecting lever and a crank. It has no intermission, no concussion and no abnormal sound. When the high-pressure fuel comes into the meter it drives the four pistons to complete an operating cycle. The volume of fuel discharged by an operating cycle is 0.473L. An adjustment hand wheel can be used to correct the accuracy when necessary. When turning clockwise, the delivery capacity will be reduced; when turning anti-clockwise, the delivery capacity will be increased. It is easy, accurate and stable. The meter can be adjusted one hole at a time. It can also be adjusted a half-hole distance. A one hole distance is about 0.10%. After adjustment, insert the lock pin and seal with lead (adjusting operation must be authorised by the relevant local authority). (See Fig. 14-1).
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LFM-473 Flow Meter Exploded View
1. Retaining Ring External 2. Pin 3 x 16 3. Bolt M5 x 12 4. Shaft Cover 5. Gasket 6. Oil Seal 7. Upper Housing 8. Bolt M8 x 22 9. Big Seal Ring 10. O-Ring 38.7 x 3.55 11. Spring Base 12. Spring
13. Valve Cover 14. Transmitting Shaft 15. Distribution Valve 16. Tightening Nut 17. Bolt M5 x 12 18. Valve Base 19. Gasket 20. Housing Assembly 21. Upper Adjusting Liner 22. Plug 23. Key 24. Cam Shaft 61
25. Bottom Adjusting Liner 26. Upper Connecting Rod 27. Roller Wheel Assembly 28. Leather Bowl 29.. Press Board 30. Bolt M5 x 16 31. Seal Gasket 32. Adjustment Cover Assembly 33. Bolt M8 x 22 34. End Cover 35. Bottom Connecting Rod
LFM-70 Flow Meter
1. Gasket 2. Circlip 3. Sort shaft 4. Main Gear 5. Circlip 6. Open pin 1.2 x 8 7. Sub gear 8. Pin 9. T-sleeve 10. Cover 11. Elastic Cylindrical pin 12. Big Gear 13. Pin shaft 14. Nut M8 15. Adjustment plate 1 16. Adjustment plate 2 17. Spring 18. Elastic Cylindrical pin 19. Pinion 20. 20 Slotted screw 21. External connecting plate 22. Locking nut 23. Vice-drive bevel gear 24. Gasket 25. Adjustment shaft 26. O-Ring 27. Gasket 28. Elastic Cylindrical pin 29. Main drive bevel gear 30. Plug 31. Hexagon bolt 32. Spring pad 33. Upper pad 34. Active compressed sleeve 35. Copper sleeve 36. PTFE gasket 37. Plate 38. Active plate 39. Locking Circlip 40. Slave gear 41. Ceramic Ball ?16 42. Active nut 43. Pin 44. Locking nut 45. Bracket 46. Three-jaw frame
47. Cylindrical pin 48. Cross-slot screw 49. Gasket 50. Steel Ball Bowl 51. Active push-pull rod 52. Pistons 53. Compressed Block 54. Piston bowl 55. Valve 56. Piston Plate 57. Screw 58. Cover 59. Shell 60. Bottom pad 61. Bottom cover 62. Sleeve 63. Adjustment shaft 64. Screw 65. Circlip 66. Bevel gear drive spindle 67. Sleeve 68. 90-degree angle block 69. Bevel gear drive Vice shaft 70. Copper sleeve 71. Gasket 72. Oil seal 73. Shaft 74. Pin 75. Spring slice 76. Nut 77. Steel Ball 78. Vice-gear adjustment 79. Limited cone pin 80. Bracket boot 81. Hexagon bolt 82. Self-locking slice 6 83. Circlip 84. Pin 85. Gasket 86. Active Rotor 87. Slotted screw 88. Spring pad 89. Pin 90. Hexagon screw 91. Allocation seat 92. Pin 62
7. AUTOMATIC NOZZLE & SOLENOID VALVE Section 1. Construction and Working principle of Automatic Nozzle
The nozzle is the terminal station of the hydraulic system in the dispenser. It is a tool used to dispense fuel into a vehicle's petrol tank. Use of a nozzle is convenient during the fuelling operation. It must be able to adjust the flow rate and be safe and reliable during usage. Nozzles commonly come in two types, the automatic nozzle and the manual operation nozzle. Manual nozzles are seldom used in the market and will therefore not be discussed in this handbook. All our dispensers use the automatic nozzle. It can be guaranteed that during fuelling the nozzle will shut off automatically when the petrol tank is full. Fuel oil will not overflow maintaining cleanliness and ensuring the safety of the petrol station. A. Construction of Automatic Nozzle
As shown in Fig. 15, the Automatic nozzle mainly consists of a nozzle body, main valve, top shaft, membrane switch valve, automatic shaft, self-shut shaft, secondary valve core, and nozzle. The nozzle is constructed as follows:
There are holes along the circumference of the secondary valve seat connecting with the upper chamber of the membrane switch through an angular hole inside the nozzle body. Air flowing through the breathing nozzle and tube passes through an angular hole on the spout connector into the upper chamber of the membrane switch. The lower chamber of the membrane switch is connected with the outside environment through gaps between the body and the automatic shaft.
There are three steel balls inside the hole above the automatic valve. When the nozzle control lever is pressed the three steel balls will clamp onto the automatic shaft due to the sloping face of the body and prevent the automatic shaft from moving downwards. When the self-shut shaft moves upwards, the steel balls will move towards the centre of the automatic shaft, allowing the shaft to move downwards. The control lever will loosen the supporting point and cause the main valve to shut off.
There is a preset lever on the control lever. When used together with the grade level plate the fuelling flow rate can be set to three different levels. The main valve opens at three different levels, resulting in different flow rates.
There is a spring which coils around the nozzle spout. During refuelling it prevents the nozzle from slipping out of the vehicle's petrol tank.
B. Working Principle of Nozzle
During refuelling, the main valve opens and pressurised fuel oil flows into the nozzles main chamber. Gaps in between the secondary valves overcome the tension of the spring opening secondary valve allowing the fuel to flow out through the nozzle spout (see Fig. 15). The function of the secondary valve is to prevent the oil fluid, between the main and secondary chambers, flowing out through the spout when the main valve is shut off. During preset fuelling when the refuelling is completed, if the main valve has not shut off, the secondary valve can prevent the oil fluid inside the nozzle and hose from flowing out through the spout. When fuel oil flows through the secondary valve it causes the pressure in the upper chamber of 63
the membrane switch to drop. However the upper chamber is linked to the outside atmosphere via an angular hole on the spout, an air inlet tube, and the breathing nozzle at the tip of the spout. This allows external air to keep flowing into the upper chamber thereby balancing the pressure between upper and lower chambers (atmospheric pressure). When the fuel oil fluid floods the spout, the upper chamber is isolated from the atmosphere causing a negative pressure. However the lower chamber remains at the atmospheric pressure forming a pressure difference ? p between the upper and lower chambers. When ?p reaches a certain limit, the membrane switch on the fixed automatic shaft will move up overcoming the tension of the spring on the upper chamber allowing the steel balls to drop into the automatic shaft. The automatic shaft will move downwards due to the pulling force caused by the control lever. The top shaft of the main valve will move downwards because of the control lever loosening the supporting point. This shuts off the main valve and the fuelling operation is ended. C. Failure and Solution for Automatic nozzle.
If the nozzle cannot be shut off, or if when it is shut off there is still an amount of oil leaking out, the cause could be a foreign object between the main valve and valve seats. Alternately the fault could be with the spring of the secondary valve. To correct this problem, clean the main valve and lengthen or replace the spring.
If the nozzle cannot be sealed tight the upper cover and the membrane may not be tightly sealed or the screws are not properly tightened. The O-rings on the spout connector or secondary valve could also be damaged leading to the upper and lower cavity not forming a pressure difference. The solution is to tighten the screws on the plastic pressure cover and replace damaged O-rings. Another problem occurs when the nozzle is not tightly sealed and allows a small amount of flow leakage. This is due to a low volume flow, weak air suction, and a small pressure difference between the upper and lower cavity of the membrane which is unable to overcome the tension of the spring to move the shaft upwards and seal off the flow. The solution would be to reduce the tension of the spring.
If the nozzle frequently shuts off without any flow, the flow-tube in the spout may be jammed with dirt causing an inconsistent inflow of air. Another reason could be that the tension of the spring in the upper cavity of the membrane is too weak which could cause frequent shut off's. The solution is to clean the dirt inside the breathing tube in order to maintain a good airflow and to suitably adjust the tension of the spring.
During fuelling if there is little or no flow the filter in the nozzle may be blocked or the membrane may be malfunctioning.
The nozzle leaks. Most leaks take place between the joints of the nozzle and the hose, the joints of the nozzle and the spout, the top cover of the main nozzle valve, or the O-shaped seal ring at the top of the main valve may not be pressed tight or is damaged.
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Automatic Nozzle Diagram
1. 2. 3. 4. 5. 6. 7. 8.
Nozzle body Press Nut Top shaft O-Seal Ring Spring Pressure Cover Main Valve Upper Cover
9. Membrane Switch 10. Self-shut Shaft 11. Steel Ball 12. Secondary Valve Seat 13. Spout Connector 14. Breathing Nozzle 15. Breathing Tube 16. Spring
17. Nozzle Spout 18. O-Seal Ring 19. Spring 20. Secondary Valve Core 21. Automatic Shaft 22. Pre-set Level Lever 23. Level Plate 24. Control Lever
D. Ways to use and maintenance of nozzles.
When using the nozzle it should be handled gently. The shaft of the main valve should be oiled regularly to ensure flexibility and reliability.
Keep the inner path of the oil stream and air stream free from blockages. Prevent any objects for becoming stuck inside the oil or air streams in order to prevent a malfunction of self-shut function.
When using the level lever during fuelling, even though the nozzle has an automatic shut off function, ensure that the level lever is off the level plate when fuelling is completed. This will prevent a mishap caused by petrol blowing out from the spout when the next fuelling commences.
When fuelling, air will flow continuously into the breathing tube. This can cause a lot of bubbles, which, if they cover the mouth of the spout, even though the tank is not full, will trigger the automatic shut off function. This is one disadvantage of this kind of nozzle.
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E. Rubber hose
During installation of the rubber hose, ensure that the conducting wire within the hose is properly connected to the connectors at both ends. This will prevent static electricity, produced by the liquid oil flowing through the hose, from accumulating and ensuring the safe use of the dispenser machine. A multi-purpose tester can be used to test the resistance of the spout. The resistance should be less than 10 Ohm.
During installation of hoses, do not leave any rubber debris inside the hose causing blockage or affecting the main valve. The O-ring inside the nozzle swivel will leak due to friction caused over a period of time. When this occurs replace the O-ring.
When using the hose prevent any bending and/or compression (such as allowing a vehicle to roll over the hose). The length of the hose should not increase unnecessarily and must definitely not be replaced with any ordinary type of hose. The reason for this is that, when under great oil pressure, using a hose which is too long, or using an ordinary hose, will cause the inner volume of the hose to expand too much. This will affect the dispenser when fuelling starts, causing the meter to jump and affecting the accuracy of the meter reading. An ordinary hose will also not have static wiring installed with the result that when fuelling static electricity will accumulate when in contact with the vehicle's oil tank and can cause sparks that will endanger the safety of the petrol station.
Section2: Structure and principle of work of a Solenoid Valve A. The usage of a solenoid valve is an additional installation to increase the accuracy of the dispenser when using a preset fuelling setting.
When the preset fuelling (such as 10 L) is complete, the electric motor should stop rotating immediately. But in actual fact during the instantaneous of the motor stopping, due to the flow speed of the nozzle are different, electric motor's load are different, therefore the motor will occur different level of over rotating due to the nature habit of the lubricant oil in the compressor cannot immediately change from a motion stage to a halt stage. Therefore the actually fuelling will be more than the preset amount by about 0.01 – 0.4L. The computer digital display will no doubt show 10L but the actual amount of oil dispensed is 10.01 – 10.04L which is a very big discrepancy. We use the term “over flowing quantity” for this discrepancy of 0.1 - 0.04L. The greater or lesser the discrepancy of the “over flowing quantity” is proportional to the flowing rate of oil fluid in the nozzle before the pump stops. The faster the flow, the greater the discrepancy. When the flow rate is slow we can ignore the discrepancy. The function of the solenoid Valve is that during the preset filling, the solenoid valve powers on and when 0.3L remains (this is the solenoid valve's shut-off limit. This limit can be adjusted and preset) the computer will send out a signal to shut off the main valve. The main valve of the solenoid valve will then shut down and the small valve remains open until the filling reaches the preset amount. Then the computer will send out a signal to shut down the small valve. This will greatly cut down on the discrepancy of the dispenser, and increase the accuracy of the machine
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Solenoid Valve Diagram
Oil Screw Cap
Coil Group
Connector Parts Valve Cover Membrane Spring Membrane Parts Valve Body
B. Connecting and adjusting of solenoid Valve
The solenoid valves used, run on AC220V and instructions for wiring can be found on the Electric Circuit Board Connecting Chart. The preset shut-off limit is usually set at 0.2 – 0.4L. If the limit is too high it will increase the fuelling time; too low and it will result in an overflow situation. To adjust please refer to the Lanfeng Dispenser Instruction Manual – Computer Operation – Parameter Setting. C. Common faults and solutions a) No oil flow or the oil flow is too small.
When checking, first ensure that there are no foreign objects in the mechanical part of the solenoid valve. If none, proceed to check as follows: When the machine starts use your hand to feel the outer body of the valve to feel if there is any impact or if it has a “ping” sound. If there is, then there is no fault with the solenoid valve. If there is no impact and sound, check if the power supply source is working properly. Use a multi meter to check all the wiring connections on the main valve, the small valve common wire, and that the voltage is 220V when the power is on. If it is then it is most probably the coil that has been damaged. Replacing the coil will solve the problem. 67
When the flow is too small the fault is most probably that the main valve of the solenoid valve could not open. Check if the EMI Relay is damaged. The way to check this is by using a multi meter when the power is on. Check the wiring between the main valve and the common wire. If the voltage is 220V then the coil is damaged but if it is not at 220V it means that the condenser which controls the main valve is damaged. When fuelling approaches the preset amount and there is no flow, or the flow is too small, it is most likely that the solenoid valve's small valve cannot open. Check as per the above. b) During the preset filling there is no reduced flow at the end of the fuelling.
First check the shut-off limit of the parameter setting. If it is set as “0.00” then it just needs to be reset If after doing this the fault still exists check if the EMI Relay unit on the electrical board has been damaged causing the condenser to remain in the “On” position. This will cause the main valve of the solenoid to stay open. Check as per the above. D. Points to take note of
1. When checking the solenoid valve, do not work near any naked flame. Cannot forcefully dismantle the wire coil, so as to prevent any sparks as it may cause serious accident. 2. Any parts that are missing or damaged should always be replaced using original parts. This will eliminate frequent malfunctioning of the machines. 3. If the coil is damaged, disconnect the coil wire from the electrical board immediately to prevent it from affecting the transformer or other components.
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8. ELECTRONIC PARTS Following the advancement of computers, computer technology has entered into the oil dispenser domain. This makes the function of the dispenser more vibrant and complete. The fuelling operation is safer and more convenient. Fuelling operators and maintenance personnel who lack computer knowledge may have some problems. In order to help most of the operating and maintenance personnel to have a better understanding of the computer parts in our products we hereby briefly explain the theory and function, those frequent faults and solutions. A. Introduction of dispenser's electronic parts
Lanfeng dispenser's electronic parts consist mainly of EMI filter, Transformer, Power Board, Electronic Control Unit, Display Unit, Keyboard, Impulse Sensor Transmitter, and Solid-state Relay. Externally connected power passes through the filter to the transformer to step down the voltage. The power board will convert and filter the current, stabilising and exporting DC current of 5V, 8V, and 12V to the computer's Electronic Control Unit. Under the command of either the keyboard or by drawing the nozzle, a signal is sent to the electronic Control Unit. When the Electronic Control Unit receives the signal, the CPU will process and send out the command signal to operate the dispenser. The operating procedure is as follows: 1. External power source enters into the distribution board through power switches and from there into the ex connecting box and into the power board's input connection. It will go through the stages of filtration and step down voltage. Low voltage AC current will pass through stages of converting from AC to DC current, filtration, stabilizing, expand and export DC 5V. 8V, 12V current to the computer main board. At this stage, all the electronic boards are in standby mode. The Electronic Control Unit will then scan and wait for any signal coming from the keyboard and the digital display unit will also display the relevant data. 2. Drawing the nozzle or pressing the filling/unit price key on the keyboard, will send an activation signal to the Electronic control Unit. When the Electronic Control Unit receives this activation signal, it will command the display board to reset to clear the screen and, at the same time, it will also command the control units to activate the electric motor, as well as the solenoid valve, putting the dispenser on standby for fuelling. 3. When the nozzle is pressed fuel flows through the dispenser's pump, flow meter, solenoid valve, oil indicator, and nozzle, and enters the fuelling tank. When the fuel flows through the flow meter, it pushes through the piston inside the flow meter and creates a reciprocal motion, flows out at a fixed volume, passes a series of transmissions, and rotates the rotating shaft of the impulse sensor unit. The rotating shaft will then drive the disc, combining the double beam sensor and the cutting notch on the disc. This will produce a pulse signal. The signal will then be sent to the Electronic Control Unit. The CPU will process this signal by re-arranging, calculating, store and display. If the CPU receives a signal without an impulse, it will recognise it an as error signal and the dispenser will remain in the shut-off stage. 4. When the nozzle is put back into the holder or the STOP key is pressed, the filling signal is shut-off. The Electronic Control Unit will send out a shut-off signal but the display unit will still display the amount of fuel that has been dispensed until the next filling starts and clears this display. 69
5. The above is for non-preset filling. If doing a preset filling, the preset value must first be keyed in. When the filling quantity reaches the preset value the electronic Control Unit will send a shut-off signal to the controlling units and the preset filling process will end. 6. Because different countries use different voltages and frequencies, the computer's transformer, ways to control the electric motor various. Please refer to various different model of dispenser. B. Operational principle of electric circuit board 1. Operational principle
The external power source, after being filtered by the EMI filter, is stepped down by the transformer into three groups of weak current, viz. AC/13V (7V), AC15V, AC17V, and through the process of conversion stabilising, expands and outputs a current of DC5V, DC8V DC12V supply to the computer's Electronic Control Unit. At the same time, connecting with the connector on the electric circuit board is relatively controlling the electric motor and solenoid valve. 1. Power Board Wiring Chart
In the circuit board (1), (2) and (3) are three phase wiring, 380V, (5) neutral wiring, 220V, (3) machine earth wiring, (6) controlling solenoid valve – small valve (blue), (7) controlling solenoid valve – main valve (brown) solenoid valve – common wiring. In the circuit board, (1) and (2) are connected to an external power supply; (3) earth wiring for the whole machine; (4), and (5) is for the transformer's secondary output wiring providing supply to the solenoid valve; (5) neutral wiring; (6) controlling wire for the solenoid valve – small valve; (7) wiring for solenoid valve – main valve, common wiring of the solenoid valve is connected to (5), earth wiring connected to (3). (8) And (9) are connected separately to the “+,-“pole of the solid-state relay. When the machine is in standby mode the electric current is at DC5V. Socket (1) is the fuse for the electrical supply. Socket (2) is for output from (1), (2), and (3) three connecting poles. 70
Connect to EMI Filter F ilter,, socket (3) is output of secondary low voltage AC current from the transformer, transformer, for (4,), (5) these two sockets are of stable low voltage DC current supplied from a secondary stage of the transformer after the low voltage AC current has been converted, filtered, stabilised. Socket (5) is also supply providing for background light for the display board. Socket DC12V provides power po wer supply to the nozzle noz zle as well as the central control unit's power supply. supply. DC5V provides power supply to the impulse sensor, sensor, computer main board and display board and DC8V provides power supply to the computer Electronic Control Unit and display board. 3. Electric Circuit Circuit Board's Board's frequent frequent faults and failure, failure, and and maintenance maintenance methods methods
When checking the circuit board for faults, first ensure that all power socket plugs are tightly plugged in. This is to prevent the socket socket plug loosening when the dispenser vibrates. A power supply failure can be due to a circuit board failure or external supply connection failure. Always Always check the external supply first first for any problems. Having eliminated any faults from that source proceed proceed to check the circuit board. Common circuit board faults are: No power supply to the dispenser, dispenser, power supply failure from time to time, computer Electronic Control Unit hanged. Below are methods for rectifying these faults. a) No power power suppl supplyy to the dispe dispense nserr at all: all: 1. It may be the fault fault of the externa externall connecting connecting socket, socket, causing causing a failure failure in supply supply of AC current to the dispenser. dispenser. Use a multi meter to check the connecting socket socket between (1) and (2) to see if the voltage in between is normal (the dispensers usually require 380V voltage; between (1) and (2) connecting poles po les the voltage is 380V). 2. Check the the socket socket on (1) to see if the the fuse is is burned out. out. If so, replace replace the the fuse. fuse. 3. Check the the output voltage voltage for for EMI filter filter as well as as the input input voltage for for the transfo transformer rmer.. See that it is working well (the value tested should be the same as between (1) and (2) of the connecting pole). If the value value is abnormal, then the fault fault is with the filter. filter. If the value value is normal then proceed to the next step. 4. Check the the secondary secondary socket socket of the transfo transformer rmer (3) to see see if there there are two groups groups of AC7V AC7V (AC13V), one group AC18V, AC18V, one group AC17V, AC17V, one group AC15V current. If there is not it means that the transformer transformer is damaged. If there is, proceed to the next step 5. Check if the DC current current of 12V 12V, 5V and 8V on socket (4) is normal. normal. This This can be checked checked using a multi meter. meter. Put the black test pen on the earth wire wire (yellow), the red pen on both 5V and 8V, 8V, and when testing the 12V, 12V, put the test pen on two points poin ts of the 12V. 12V. If the reading is normal, this means that there is a fault with the computer's Electronic Control Unit. If the reading reading is abnormal, then the fault is with the electrical circuit board. The two groups of direct current for the socket are to provide power to light up the background of the display board; yellow wire is for earth. When empty, empty, load is 8V (13V during the filling. Oxidation of the plug pin on the socket (3) and (5), will affect the conductivity causing the background light on the display board not to work.
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b) Failure Failure to have have power power supply supply on and off, off, or slow in startin startingg up A problem on both the electrical circuit board and the Electronic Control Unit can cause frequent power failures failures thus preventing the machine from starting. A mechanical problem problem can also be the cause of difficulty in starting the electric motor. motor. In this section however, however, we will only discuss faults on the electrical circuit board. b oard. 1. Check the the external external power connect connection ion to see if the the power network network voltage voltage is too too low or unstable, or if the self provide provide power generator's voltage is too low or unstable. Both will cause the problem. 2. Check the electric electrical al supply circui circuitt board to see if the output voltage voltage to the Electronic Electronic Control Control Unit is too low or is unstable. If it is, the fault will will be on the electrical circuit circuit board. If not, it may be a fault on the computer's main board. 3. When the dispenser's power is off, off, use a multi meter (DC20V) to test the EMI relay's relay's DC5V. DC5V. See if the voltage is normal. If abnormal, it means that the electrical board board has a fault. Conduct a further test with the relay relay when the power is on. Test between each wiring connection from the relay to see if the voltage is normal. If a relay fault fault is the cause of the failure to start the electric motor mot or,, or slow rotation, this should be avoid to prevent damaging the electric motor. c) Failu ailure re to to star start. t. 1. First check check the source source of the external external power supply supply to eliminate eliminate the external external factor factor.. 2. When the dispens dispenser's er's power power is on, test test the EMI solid solid state relay' relay'ss DC5V to see ifif the voltage voltage is normal. This can also be seen from from the control indicator's light on the relay relay.. If there is no indicator light, then check the electric circuit board's 5V wiring between (8) and (9) when the power is on to see if the voltage voltage is normal. If it is normal it means that the relay relay is faulty. faulty. If the test shows no voltage or very low voltage, check the on/off indicator indicator signal on the main board. If there is no indicator signal signal it means that the computer main board has has a problem. If there is an indicator signal, please check the plug connection or the power supply main board. 3. A damaged damaged EMI relay relay or electri electricc motor could could also lead lead to failur failuree to start. start. d) Dispen Dispenser ser fails fails to shutshut-off off With the dispenser's power off, check the control indicator light on the relay to see if it is off or at 0V. 0V. If it is, it means that there is a fault with the relay. relay. If not, then the problem is with the Electronic Control Unit. In the next chapter chapter we will introduce keyboard malfunctions as well as problems with the nozzle noz zle on/off switch. e) Soleno Solenoid id valv valvee will will not not open open If this situation occurs, first check whether the fault is with the solenoid valve or the t he power circuit controlling the solenoid valve. This can be tested during the split second between on/off. on/off. Use the hand hold on the body of the solenoid valve, valve, when switching the dispenser 72
“on” or “off” to see if the solenoid valve makes a noise or vibrates when starting or shutting off. off. If there is a noise or vibration, there is no problem with the solenoid valve; valve; if not, you should check the power supply controlling the solenoid valve. Use a multi meter to check on the connection between the main, small valve valve and the common wire. The voltage during power “on” should be 220V. 220V. If it is, it means that the solenoid valve is faulty and needs to be replaced. If not, assume that the fault fault is with the power supply circuit circuit of the Electronic Control Unit. f) Solenoid Solenoid valve valve cannot cannot be be shut shut down or or there there is no no reduced reduced flow. flow. The reason for this is that during d uring the shut-off stage the Electronic Control Unit cannot send a command signal to shut off the main and small valve due to damage of the relay on the power supply board. When there is no reduction reduction in flow it usually means that either either the connections of the main and small wire have been reversed or that the relay controlling the main solenoid valve valve is damaged. Replacing the relay will solve the problem C. Function Function of the the computer computer Electron Electronic ic Control Control Unit Unit 1. Descri Descripti ption on of the fun functi ction on
The LANFENG dispenser's Electronic Control Unit consists mainly of a CPU processor and memory device, with various various connections. The CPU processor processor is the control control centre of the dispenser, dispenser, controlling all the functions of the dispenser. dispenser. During refuelling it receives the signal from the impulse sensor which which it then processes. At the same time it can accurately accurately detect if the impulse sensor is connected correctly to the electric circuit or if the impulse sensor is in working order. order. If the CPU detects that the impulse sensor is not properly connected to the electric circuit, or that it is not in working order, order, it will shut off the t he electric motor and the solenoid valve. The memory device has perfect the protection function function during a blackout. blackout. During sudden blackout, it will will guarantee safe storage of the dispensing data. It also has the ability to prevent any interference when under such as high temperature, tem perature, low temperature, dense, sand storm, dust, fuel vapour contamination, strong magnetic interference, strong radioactive condition, and it will still be able to work as in a normal situation to store and read data. 2. Work Workin ing g theo theory ry
When sources of direct current, DC5V, DC5V, DC8V (13V), DC12V coming from power supply board supplying to computer's Electronic Control Unit, dispenser is now on standby stage. Upon receiving the “Start” signal from the on/off switch or keyboard the Electronic Control unit will give the command to start the electric motor and the solenoid valve. valve. The display screen will reset to zero. The nozzle is on during the filling and and the impulse sensor sends a pulse signal, equivalent to the amount of oil filled, to the Electronic Electronic Control Unit. The CPU will then process process and check the signal, display, display, and store.
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Electronic Control Unit Chart
Plug (1) is the mechanical counter attachment; the LANFENG dispenser can preset the mechanical counter at the user's request. Plug (2) is the on/off connection for the nozzle. At the side there is a red indicator light L1. When the switch is “on” the indicator lights up and the signal is sent to the CPU. When the light is off, meaning the signal is terminated, refilling is stopped. Plug (3) is the central control connection. When connected to the computer it can exchange data. Plug (4) is the DC12V voltage source from the electric power board which provides power to the central control's communication voltage as well as the nozzle on/off voltage. It has a red indicator light L2 at the side that indicates whether the communication signal is sent through (on), or not (off). Plug (5) is the back-up battery connection that supplies power to the Electronic Control Unit during a power failure. The voltage is normally 6.5V which is sufficient to store and display all the filling transaction data during a power failure. If a short loss of display occurs pressing the “Power Failure Reading” key will restore the display of the last amount filled. Plug (6) is the power connection from the electrical board to the Electronic Control Unit. It consists of DC5V, DC8V, DC8V (13), and an earth wire. Plugs (7) and (8) separately (suggestion) respectively provide a power supply and communication connection for both front and back display units. Plug (9) is the connection between the electric motor and the solenoid valve controlling wire. When the two green indicator lights L6 and L7, light up it means “ON”; lights off means “OFF” Plug (10) is the impulse sensor connection, with DC5V voltage providing for light sensor functions. Two indicator lights L4 and L5 at the side indicate whether the sensor is sending out a pulse signal. Plug (11) is the command signal connection between the keyboard and the Electronic Control Unit, and is Corresponding control. 3. Common faults of Electronic Control Unit.
Under normal conditions, first eliminate all other faults before considering that the dispenser's Electronic Control Unit or Keyboard is at fault. 74
a) The Dispenser won't start. First check that the data keyed in is valid and is as per the filling procedure requirement.
Check the “Filling/Unit Price” key to see if it is working properly. Also check that the electronic switch is set at “Operating” position and is in working condition and check the Electronic Control Unit to see if the plug connection for the Nozzle's on/off wiring and keyboard wiring are intact. To check this, unplug the socket for the nozzle on/off and use a screwdriver or other tool to short-circuit the KS and VSS. If the dispenser starts it means that the fault is with the keyboard. If it does not start then the fault is with the Electronic Control Unit's main board.
If the above are all in working condition and you have yet to solve the problem, check that plug (9) is not loose. Also observe the indicator lights L6 and L7 when the power is “on”. If they do not light up then the fault is with the controlling unit. If the lights are on then proceed to the next step, or check it with a multi meter, set at DC20V. Put one end of the test pin on the Electronic Control Unit's earth wire and with the other end separately check the reading on the plugs two wires. With the power “on” the reading is at low voltage of approximately 0V and when the power is “off” at approximately 5V.
If the Impulse sensor's cross pin is missing or broken there are two places to check. One is to see if the indicator lights L4 and L5 beside the impulse sensor, light up. If they do not light up the fault could be with the impulse sensor or the indicator lights are damaged. If the indicator lights up, we may consider that the fault is with the CPU or other electronic components.
b) The Dispenser won't shut off First check that the nozzle's on/off connection is not damaged. The methods for checking this will be explained in the following chapters. Also check that the “Halt” key is not faulty.
Check the relay which controls the Ex Motor when the power is “off” to see that it still has a power supply to drive the motor. If there is a power supply then check the relay's control signal to see if there is a direct current of 5V. If there is then the fault is on the Electronic Control Unit's main board. If there is no 5V current it means that the relay is damaged.
c) Dispenser's power is “on” but the display board is blank or the display is distorted. First check the impulse sensor to see if there is a signal. To check this, see if there is a voltage of 5V and if the G1 and G2 pins are in working condition. At the same time try turning the disc on the impulse sensor transmitter and observe if the indicator light on plug (10) blinks. If there is no signal then the fault is with the impulse sensor board. If there is a signal, then it is an Electronic Control Unit fault.
If the cross pin of the impulse sensor is damaged or the screws are loose, causing nonrotation of the disc, no impulse signal will be sent to the Electronic Control Unit resulting in no display.
A distorted display is mostly caused by a fault on the display unit or the connection plug
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being loose. If the Chip on the Electronic Control Unit, which controls the display, is burned out, it can also lead to a distorted display. (d) When there is a power failure, data shown on the display screen is lost and even pressing the “Power Failure Reading” key will not restore the last display amount. Check the keyboard unit and Electronic Control Unit's main board to see if the connection between the two is intact
Check that the “Power Failure Reading” key is in working condition.
Check that the back-up battery power is adequate or if the plug is loose. Us a multi meter (DC20V) to check if the voltage is at 6.5V. If it is, then the fault is with the Electronic Control Unit's main board. If not, then replace the back-up battery.
e) When using preset filling, the dispenser will not stop filling when the preset amount is reached. There is a fault on the Electronic Control Unit's main board
The preset figure is incorrect. E.g. litre and amount are mixed up.
(f) Solenoid valve will not operate or shut-off. If after eliminating some external factors (external power source, electric main board, solenoid valve, keyboard and wiring connection) the problem still exists it means that the fault is with the Electronic Control Unit's circuit board. This can be ascertained from the “on” or “off” of the indicator light L7. D. Keyboard and Display Board
The keyboard is the input unit of the dispenser. It consists of a series of keys and switches, operating personal input data, addresses or commands to the Electronic Control Unit using the keys and electronic lock on the keyboard. The LANFENG dispenser's “Fuelling” and “Halt” keys together with the nozzle switch can both be operated generally or concurrently. A keyboard fault is commonly due to a key pad defect, electronic lock missed position or abnormal position, or the keyboard wiring has become loose. The Dispenser's LCD display board has a 5V, 11V back light. In theory its job is to convert binary data to the more familiar decimal based data and to display it. The display board is made out of an LCD plate, back light plate, circuit address distributor, and encoder circuit. A common fault of the Display Board is that the LCD displays distorted numeric figures with some strokes missing or displaying a figure which is not clear, or blurred, and the back light won't light up. Numeric figures with missing strokes, or blurred figures, are usually the result of damage to the LCD caused by things such as poor soldering, loose pins, broken pins, etc. Re-soldering or replacing the LCD will fix this. The other problems are caused by loose wire connections or damage to the circuit or components of the display board 76
E. Nozzle Switch and Anti-Explosive Impulse Sensor Unit
a) The Nozzle Switch consists mainly of a magnet, breaker tube (magnet and breaker tube are glued separately inside a plastic square), steel bracket, baffle plate, spring, and shaft. During filling, when the nozzle is drawn out of the holder, the magnet, which is attached to the rotating shaft, will swing to line up with the steel bracket switch due to the weight of the baffle plate as well as the tension of the spring. The contact spring within the breaker tube, which is fixed on to the steel bracket, will then contact due to the attraction of the magnet, transmitting through two wires and short circuiting the KG and VSS points on the main circuit board. This sends out an operating signal and when the nozzle is replaced in the holder, the magnet swings off the steel bracket switch, the contact spring inside the tube breaks away due to the lost magnetic attraction, triggering the shut-off signal. Common problems with the nozzle switch are: When drawing the nozzle, the dispenser won't start or when the nozzle is placed back into the holder the dispenser won't shut off, and the switch won't operate. After eliminating all other factors, check on the magnet to see if it is damaged or if the magnetic force has weakened. Check that the contact spring within the glass tube works well under the influence of the magnetic field (use a multi meter to test its resistance). Replace whichever is damaged or faulty. b) Anti explosive Impulse sensor The Impulse sensor is a unit which sends a signal to the Electronic Control Unit. It comprises a dividing disc with a cutting notch, and double beam circuit. During operation, while the flow meter is discharging a fixed amount of oil fluid, it drives and rotates the dividing disc of the impulse sensor unit. The double beam light above the disc shines through the cutting notch while the disc is rotating sending out an impulse signal. Common problems of the Impulse sensor are: Not counting during filling or inaccurate amount shown during filling. First check that the rotating shaft is rotating, and the cross pin for damage. The binding screw for the dividing disc may also be loose or may have fallen out preventing the disc from rotating and resulting in no impulse signal. This can be observed from the main board's indicator light L4, L5. If w/o signal then the double beam light circuit is damaged. If there is a signal then the problem is with the main board of the Electronic Control Unit. In the case of inaccurate counting, first eliminate external factors (fair wear and tear of parts of the flow meter) before considering the following impulse sensor is faults: the Dividing Disc is tilted or loose or the rotating speed varies. Dirt in the notch groove may also affect the output of the impulse signal, causing inaccurate counting. Adjusting the dividing disc, tightening the binding screw, or cleaning the notch groove or double beam light should resolve the problem.
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9. FUEL DISPENSER MALFUNCTION In the previous chapters, we introduced the common faults of every part of the fuel dispenser as well as ways to rectify them. (This manual emphasizes more for the suction pump fuel dispenser). In the actual maintenance and repair process, it is difficult to judge which parts have faults and their cause. Because the dispenser is a combination of all kinds of mechanical parts and electronic components, the same fault may be caused by a number of things and can also lead to a number of malfunctions. The dispenser cannot operate by itself. It must combine effort with exterior equipment (such as power supply connection, oil tank, oil pipes, and so on) to operate. A fault in one of the external components can also cause the dispenser to malfunction. Therefore, in order to do a fast and accurate assessment of the cause and location of the malfunction, one must have a general theoretical knowledge and experience to support and understand the relationships between the cause and the incident. Here below, we introduce ways to judge and rectify malfunctions of the dispenser. The rectification for those malfunctions that have already been discussed in previous chapters will not be repeated here. A. Not fuelling
1. The Ex Motor's wiring is connected in reverse or the driving belt is loose or broken. To rectify, check the sequence of the wiring; adjust the tension of the driving belt or replace it. 2. Malfunction of Oil Tank, Oil Piping and Foot Valve. Lack of oil or no oil in the oil tank (refuel).
Oil piping connection between oil tanks and fuel dispensers has a large gas leak. (reinstall or try sealing it tightly)
Foot valve is blocked, jammed or damaged due to rust. (Clean or replace the foot valve).
Improper pipeline design, e.g. Pipeline between two fuel dispensers does not have any valve or the valve cannot be tightly shut, the pipeline is too long and narrow, or the pipeline may have too many bends. (Redesign and re-run the piping).
Oil tank's ventilation pipe is obstructed or blocked. (Clear the ventilation valve or replace it).
3. Malfunction of the pump. Pump cannot rotate. (Replace or repair)
Pump severely worn out. (For LFYP-50 vane pump, replace the inner and outer copper ring cover of the main shaft. For LFCP-90 gear pump, replace the inner or outer gear wheel)
Overflow valve's valve core and valve body have clearance, or is blocked by a foreign object, or damaged, leading to internal leakage. (Clear or replace).
Pump filter is severely jammed. (Clear filter net or replace).
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Return valve in the pump cannot be tightly closed so no vacuum is formed. (Clean out the dirt inside the return valve, or check the floater in the valve).
Discharge valve is rusty. (Clear or replace).
Using improper product such as oil with moisture, causing inner components and parts of the pump to freeze during low temperatures. (Replace lubricant oil or repair pump).
4. Malfunction of Flow Meter Flow meter jammed. (Check for a foreign object or damaged parts).
After a repair service the distribution valve was incorrectly installed. (Re-install)
5. Malfunction of Solenoid Valve. Default of the control circuit leading to solenoid valve cannot be open. (Check and repair control circuit unit).
Due to a fault with the solenoid valve's coil, or blockage of the valve membrane passage, leading to solenoid valve not opening or not having proper oil flow. (Repair or change the solenoid valve).
6. Malfunction of Nozzle Nozzle's filter net or connector is blocked.
Nozzle's main or sub-valve cannot open.
Nozzle remains in shut off stage. (Check the air tube to see if it is blocked and that the selfseal spring is in good condition).
7. Malfunction of Anti-Explosive Impulse Sensor. The impulse sensor's usual default is caused by a jamming of the rotating shaft. (Dismantle and repair. Ensure good rotation). B. Dispenser having small flow.
1. Drive belt too loose causing slipping action. 2. Oil tank, oil piping and foot valve. Oil tanks don't have proper air inlet flow.
Piping connection between the oil tank and dispenser has air leak. This can be seen from the oil indicator. At the same time air can be seen belching out from the vent tube of the pump.
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Opening of the foot valve is too narrow.
3. Malfunction of oil pump Filter of pump is too dirty or blocked.
Tension of the adjustable spring inside the pump overflow valve is too weak. (Adjust the screw sufficiently, by turning it clockwise, or add or replace gasket).
The pump's vane blades are worn out. (As for the gear pump there is the inner and outer gear 1 worn out) This will cause a loss of vacuum or a lower vacuum than required. (Replace the vane blade or gear wheel to ensure smooth movement within the pump.
Overflow valve is jammed (cannot seal tight) or malfunctioning.
Returning valve in the pump cannot be closed tightly causing air flow into the low pressure chamber, reducing the vacuum.
Discharge valve's valve core and valve seat cannot operate effectively.
4. Fault with the flow meter; usually due to the drive shaft not turning smoothly and causing a reduction in oil flow. 5. Fault with the Impulse sensor; usually due to the rotating shaft not turning smoothly. 6. Fault with the solenoid valve; usually because the main valve cannot open (check if the solenoid valve's control circuit is faulty or if the solenoid valve itself is faulty). 7. Fault with the nozzle. C. Dispenser makes a loud noise and strong vibration during fuelling operations
1. Open end of the bottom valve inside the oil storage tank is too small, pipeline is too long, and pipe diameter is too small with too many bends, increasing the workload on the pump and producing loud noise. 2. Fault with the oil pump. Filter net in the pump is blocked causing insufficient oil supply resulting in loud noise.
Overflow valve in the pump cannot open or the adjusting screw is too tight. (Adjust the screw sufficiently, by turning it anti-clockwise, or replace the screw).
Vane blades are jammed (gears are jammed), discharging oil's beat frequency increase, causing the dispenser to make a loud noise and to vibrate.
3. When the discharge oil's beat frequency is the same as the beat frequency of the dispenser, it will also cause the dispenser to make a loud noise and increase the vibration. (Adjust the flow rate). 80
4. Some of the dispenser's component parts have become loose causing a resonance vibration. 5. When using 3-phase Ex Motor, when no phase or if voltage is too low, causing the Ex Motor to revolve abnormally and vibrate making a loud noise. D. Fuel oil flowing out from the air vent
1. When using high rack or semi rack storage tank (Block off the air vent hole). 2. Floater cannot float or float back to the designated position. 3. The air disperse pipe within the pump cannot vent properly or the sealing parts are damaged. This causes fuel fluid to fill the atmospheric pressure chamber and not be able to return to the low pressure chamber in time. 4. If too often when fuelling operation starts but no fuelling, will also cause fuel oil to flow out from the air vent. E. Air and fuel not clearly separated
1. There is an air leak in the pipeline or inside the low pressure chamber of the oil pump. 2. The return valve is open and linked with the atmospheric pressure. 3. The discharge valve of the pump is open causing a large amount of air flow into the flow meter together with fuel oil. (Dismantle the discharge valve and clean. Ensure that the valve core has an unrestricted movement). F. Inconsistent fuel flow during fuelling
1. The filter net in the oil pump is too dirty. 2. Oil pipelines have a “•¿ ¡±shape bend causing air to be become trapped within the higher end of the pipe and resulting in inconsistent fuel flow during fuelling. 3. The air vent of the oil storage tank has an obstruction, especially for petrol. (Increase the height of the air vent to not less than 4 metres or clean the air vent nozzle for a clear air passage). G. Accuracy of measurement is extremely poor
1. The dividing disc on the Impulse sensor is loose or the double beam is damaged. 2. There is a bad leak in the flow meter resulting in poor accuracy. 3. Poor air and fuel separation, causing fuelling oil to contain air vapours. 4. Computer's main board is damaged or a replaced board is not compatible with the flow meter. 81
H. Difficulty in starting the ex-motor or heating up effect.
1. Ex-motor is damaged. 2. Ex Motor is overloaded, mainly due to the oil pump jamming. 3. Solid state relay is damaged causing difficulty in starting the Ex Motor or heating up effect. 4. External wiring problem such as no phase, wiring distance too far, diameter of wire too small, or voltage too low, may cause the Ex Motor to rotate slowly or heat up. I. During refuelling, fuel flow is normal but there is no counting on computer display
1. Axle pin on the drive shaft of the flow meter is broken. (Replace) 2. Axle pin of the impulse sensor is broken or the screw for the dividing disc is loose. (Repair or tighten) 3. Wire connection board for the impulse sensor is loose or the double beam light circuit is damaged. (Replace connection board) 4. Computer main board is damaged. (Replace main board) 5. Wiring connection between display unit and main board is loose or the display board is damaged. (re-plug in the wiring socket or replace display board) 6. No counting for low volume flow but counting for high volume flow, is mostly due to the flow meter's distributor valve which has been scratched. (Repair or replace) J. Dispenser will not start up
1. External power source without phase or no power source. (Check supply source) 2. Nozzle switch or “Fuelling/Unit Price” key is damaged. (Replace) 3. The electronic key on the keypad is pointing to the “Fuelling/Unit Price” position or the electronic key is damaged. (Correct or replace) 4. Preset figure is not in accordance with the computer requirement. (Key in preset value again) 5. Connection between the keypad and the computer is loose (Plug in again) 6. Circuit on the computer main board, which controls the Ex Motor and solenoid valve, is faulty. (Replace) 7. Solid state relay is faulty. (Replace) 82
8. Ex Motor is damaged. (Repair or replace) 9. Power board supplying unstable voltage to the computer main board. (Change the power board) 10.Impulse sensor plug is loose. K. Dispenser cannot shut down
1. Nozzle holder switch is damaged. 2. “HALT” key on the keypad is faulty. 3. Circuit on the main board, which controls the Ex Motor and solenoid valve, is faulty. 4. Solid state relay is faulty. 5. During preset fuelling, if the machine won't stop when the preset value is reached, there is usually a fault with the main board. L. Ex Motor often stops during refuelling
1. External power supply source is not stable. 2. Power board supplying unstable voltage to the computer main board. 3. Circuit on the main board, which controls the Ex Motor and solenoid valve, is faulty. 4. Solid state relay is faulty. M. Display of dispenser has a phenomenon of jumping numbers
1. The underground pipeline has a leak or the bottom valve is not tightly closed and air entering the flow meter is starting the count. 2. The rubber hose is old or too long and is not according to the requirements, producing changes in inner volume and causing the numbers to jump. 3. The rotating shaft of the impulse sensor is too agile. 4. Spring tension on the discharge valve in the pump is too weak. When the fuelling stops fluid in the flow meter flows backwards, driving the impulse sensor in reverse causing the numbers to jump. N. Fuelling process is normal but display board (on one or both sides) does not display fuelling data
1. The connection between the display board and the main board is loose. 83
2. The display board is damaged. 3. The main board is damaged. O. Solenoid valve cannot open or no reduced flow during preset fuelling
1. The circuit controlling the solenoid valve is faulty. 2. There is a fault with the solenoid valve. 3. The connecting wires for the big and small valve are connected wrongly preventing a low volume flow during preset fuelling. 4. The setting for the advance shut off is too small preventing low volume flow during preset shut off. 5. There is a fault with the main board 6. Dirt inside the solenoid valve stops the valve from closing. (Clean out the dirt) P. Dispenser has an external leak
1. A damaged gasket, seal bush and O-ring will cause leaking. 2. Damaged components and parts. Q. Dispenser has an electric leakage.
1. Insulation on the coil wire of the Ex Motor is damaged causing leakage. (Replace the Ex Motor) 2. Surrounding environmental dampness or the insulation capacity of the wire connecting the board is reduced. 3. External connecting wire has torn insulation and is making contact with the metal structure of the dispenser. 4. The electric circuit within the dispenser is faulty. 5. There is no reliable earth for the dispenser and no proper leakage protection circuit. 6. When the dispenser has an electric leakage it can easily cause a fire and/or personal injury. If a leakage is detected the power supply must immediately be shut off and the dispenser must not be used until the problem has been resolved.
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10. PETROL STATION DESIGN Section 1: Building requirement of Petrol Station A. Station control room
It is more suitable to build the station control room at ground level with the indoor floor lever about 20cm higher than the ground. The building height must not be less than 3.5 metres. Flooring should be of non-combustible material. The door should open outwards and the window must be wide and transparent providing good observation. When constructing the station control room, office, rest room, and power supply room, the station control room should be positioned in the centre facing the dispensers for ease of observing the traffic flow in the station. The distance from the dispensers to the control room must not be less than 5 metres. B. Power supply room
(Distance for dispenser, oil storage tank, surrounding buildings and traffic line of a petrol station.) Safety Guide Diagram
Station Class
Grade 1
Item of Storage
Item Naked Fire or Possible Fire Hazardous Public Building Public Fire Buildings and Resistance Other Rating Buildings
1st & 2nd Grade 3rd Grade 4th Grade
Main Roads Overhead Communication Cable
National 1st & 2nd Grade General
Grade 2
Grade 3
Above Underground Above Underground Underground ground ground Storage Tank Storage Tank Storage Tank Storage Tank Storage Tank 30 50
30 50
25 50
25 50
17.5 50
12
15
6
12
5
15 20
20 25
12 14
15 20
10 14
10
15
5
10
No Restriction
1.5 Time pole height. Must not cross over the station.
Overhead Power Supply Cable
1.5 Time pole height.
Must not cross over the station.
The walls between the power supply room and the other neighbouring explosion hazard areas must be solid and non-combustible. There should be no process pipeline passing through the room. All the holes for windows and walls must be tightly filled with non-combustible material. Doors and windows for the power supply room must open outwards, facing the non-explosion hazard area. A low voltage switchboard can be positioned inside the control room. The distance between the room doors and windows where the switchboard is, and the dispenser, air vent of the storage tanks, and the tightly sealed storage tank filling inlet, must not be less than 5 metres. 85
C.
Fuelling island
The fuelling island should be 20cm higher than the ground and the width must not be less than 1.2 metres. The covering shelter should be a concrete structure with a height of not less than 4.5 metres. The shelter must be able to cover all the dispensers and the surrounding operating area to protect them from sun and rain. D.
Parking lot and drive way
The driveway and parking lot in a station should be constructed with concrete material with a thickness based on a load-bearing calculation. Tar-paved road surfacing must not be used. The entrance and exit of a station must be separate. The slope of the entrance or exit must not be greater than 6 degrees. The width of the driveway must not be less than 5 metres and the radius for turning bend not less than 12 metres. Section 2: Storage Tank and Pipeline
The storage tank commonly used in petrol stations is a horizontal round metal drum type. Here we call storage tank. Installation of the storage tank can be above or below ground. The above ground storage tank is installed above ground level and is exposed to the air. This type of installation is convenient for maintenance and repair of the tank's external wall. Visual inspection for leaks is easy. However, this type of storage is greatly affected by atmospheric temperatures, fuel oil vaporisation wastage is very high, and operational safety is lower. Advantages of the underground tank are that it is less affected by atmospheric temperatures, vaporisation wastage is small and fuel vapour will not gather around the tank. It is safer and will not occupy the space on the ground. Ground will look roomy. Disadvantages of the underground storage tank are that you cannot inspect and check the tank directly for any leakage problem. It is not convenient for maintenance or repairing of the storage tank's external wall. After a comparison of the merits and faults of the above ground and underground storage tanks it is appropriate to make the under round storage tank your first choice. GB50156-92 Small scale petroleum storage and Petrol station design specification states that “Fuel storage tank and diesel storage tank for petrol stations must be buried directly underground. It is prohibited to install the tank in a building structure or underground basement. When a petrol station is situated in a suburban area, if there is a problem burying the storage tank, then it may be installed above ground.” Underground Storage tank must meet the following requirements: 1.
The external surface of the tank must be coated with a corrosion protective coating not lower than the approved grade (refer to chart 2).
2.
When burying the tank, there must be a 30cm thick layer of fine soil or sand surrounding the tank wall. To prevent damaging the corrosion protective coating on the tank wall 86
there must be no stones or rocks in the soil or sand. 3.
The level of the concrete flooring where the tank is buried should be 15cm higher than the surrounding floor level. The walls to be built around the storage tank are to prevent ground water from entering into the storage tank area and causing the tank to float when it is empty.
4.
The inlet of the storage tank must design with operation well, for a convenient operation. The inlet pipe, discharge pipe, measuring hole, and air vent pipe should all be positioned at the inlet cover. The inlet pipe should be installed 20cm above the bottom of the tank.
5.
The diameter of the air vent pipe must not be smaller than 50mm and the inlet opening should be 4 meters or more above the ground level. If the air vent pipe is laid upwards along a building wall, then the inlet opening must be 1 metre higher than the building and the distance to any doors and windows must not be less than 3.5 Metres.
Dispensers and storage tanks are connected by pipelines. The layout of the pipeline is rational or not is concern to the capital cost of petrol station, safety operation and proper business. Specific requirements for a pipeline layout are: Anti-Corrosion Chart (Coating, Grade and Structure for
Anti-Corrosion Coating Grade
Petroleum Asphalt) Thickness of Asphalt Layers
Total Thickness of Coating
Normal Anti-Corrosion Asphalt Primer-Asphalt-Glass Cloth-AsphaltGlass Cloth-Asphalt-PVC Industry Film
1.5
4.0
Strengthened Anti- Asphalt Primer-Asphalt-Glass Cloth-AsphaltCorrosion Glass Cloth-Asphalt-PVC Industry Film
1.5
5.5
Extra Strength Anti- Asphalt Primer-Asphalt-Glass Cloth-AsphaltCorrosion Glass Cloth-Asphalt-PVC Industry Film
1.5
7.0
Structure of Anti-Corrosion Coating
The fuel delivery pipeline must adopt be a seamless steel pipe. Buried pipeline joints are to be welded, and the outer face of the pipeline must be coated with a corrosion protective coating not lower than the approved grade to prevent the pipeline becoming corroded and causing fuel vapour to leak out from pipeline and gathered. The suction pipeline for the dispenser must have a slope of not less than 2 degrees, sloping towards the storage tank. When one storage tank is supplying more than one dispenser, each dispenser must have its own inlet pipe to prevent interaction during fuelling operations. When one dispenser uses fuel from two storage tanks, there should be a valve on each delivery pipeline to prevent the influence between the two tanks. When using fuel from one tank, the valve of the other tank's pipeline should be closed. 87
The oil discharging pipe should extend to 20cm above the bottom of the tank. It should have a slope of 2 degree sloping towards the tank. When the tank truck is discharging fuel oil into the storage tank, the enclosed type discharge method must be adopted. One end of discharging pipe connecting with the tank truck must installed a quick connector, also installed with a discharging well. All the discharge pipeline connectors should be arranged at the same well so that the tank truck can discharge different fuel products from one fixed position. Select the diameter of the inlet pipe for dispenser rationally. If the diameter is too big, it will increase the capital cost of laying the pipeline, when under definite vacuum condition. Too big a diameter will cause suction problems. If the diameter of the pipeline is too small, pressure loss within the pipeline will be too great and will also lead to nonsuction of fuel oil. The common size used is 38mm ?.
Section3: Brief introduction on the knowledge of explosion proof
The power system load for petrol stations is 3rd grade. The power source adopts a 380/220V low voltage external power source. When the low voltage power source is too far away the voltage drop is greater and cannot fulfil the starting requirement. You can also use a high voltage power supply with a step-down transformer and use this as a low voltage power supply source. To ensure the safety of the petrol station, the transformer should be placed on its own in a safe place away from fuel vapour. A low voltage switchboard can be positioned in the station control room. The doors and windows of the room where the switchboard is situated must be at least 5 meters away from the dispensers, storage tank air vent hole, and the enclosed discharge well hole. In some areas where there is a power shortage problem, a small internal combustible generator unit can be set up. The exhaust pipe of the generator must be installed with an exhaust flame arrester. The horizontal level distance between the exhaust outlet hole with each vapour release source, should be: 15 metres if the exhaust outlet hole is lower than 4.5 metres, 7.5 metres if the exhaust outlet hole is higher than 4.5 metres. Most of the area within the station is an explosion hazardous zone. For this reason all the electrical fixtures used are Ex proof. The selection of electrical fixtures depends on the explosion hazardous grade of the location. 1.
Classification of explosion hazardous location
The location which can form an explosive air mixture or places where an explosive air mixture can intrude are called explosion hazardous locations and are classified under three grades: Zone 0, Zone 1, and Zone 2.
Zone 0: Area in which an explosive gas-air mixture is continuously present, or present for long periods Zone 1: Combustible or conductive dusts are present. Area in which an explosive gasair mixture is likely to occur for short periods during normal operations. 88
Zone 2: Area in which an explosive gas-air mixture is not likely to occur, and if it occurs, will only exist for a very short time due to abnormal conditions.
Zonings for explosion hazardous zone
Space above the non-inert gas liquid level of the internal storage tank is Zone 0. Inside the discharge valve well, surrounding spherical space of 1.5 metre radius with the air vent outlet hole at its centre, and also with the enclosed discharge hole as a centre point, the surrounding spherical space of 0.5 metres, all these spaces are Zone 1. Cylindrical space of 1.5 metre from the outskirts of the valve well and a height of 1 metre from ground level, spherical space of 3 metre radius with the air vent hole as centre, spherical space of 1.5 metre radius with enclosed discharge hole as centre, all these spaces are Zone 2 (see Diagram below).
Zonings for outdoor dispenser explosion hazardous zone:
Internal space of the dispenser, the spherical space of 0.5 metre radius with the hole or drain below the ground level within the hazardous zone, and with the nozzle as centre point, is Zone 1. The cylindrical space with the centre of the dispenser as centre, top radius 3 metre, bottom radius 4.5 metre, height from ground level and extended to 0.15 metre from the top of the dispenser, is Zone 2 (see Diagram on next page). 89
2. Classification, types and grouping of explosive gas mixture.
Explosive substance can be divided into three groups: Group I – Methane mine; Group II – Explosive gas and steam; Group III – Explosive dust fibre. Based on the Maximum experiment safety gap, Minimum ignition current ratio and ignition temperature to classify the type and group of explosive gas mixtures. Example of Classification of Explosive Gas Mixtures
Class
Maximum Experiment Safety Gap MESG (mm)
Minimum Ignition Current Ratio MICR
Ignition Temperature (Celcius) and Group T1 T>450
T2 450 | T>300
Ethane Propane Butane Hexane IIA 0.9
3.
0.5
Domestic Gas Cyclopropane
Butadiene Ethane
T3 300 | T>20 Hexane Heptanes Benzene Kerosene Dim Ethyl
Way to identify the type and symbol of Ex proof electric equipment.
Ex proof electric equipment comes in two types. Type I is for use in coal mining and type II is for use in factories. Electric equipment used in dispensers is generally type II. Each piece of electric equipment, based on their fixture characteristic, can fall into the increased safety type, flameproof enclosure type, oil immersion type, powder-filled type, flange protected enclosure type, intrinsic safety type, and special type. 90
Explosion Protection/Prevention Symbols
Flame Flange Increased Oil Type of Proof Powder Protected Safety Immersion Protection Enclosure Filled Type Enclosure Type Type Type Type Symbol
e
d
o
q
p
Intrinsic Safety Type
Special Type
ia, ib
s
Characteristics of different types of Ex proof electric equipment: Increased safety type (e): When operating under normal conditions, it will not produce arc, sparks or overheating, which will ignite explosive gas mixtures. It also adopts a structure measure to increase the degree of safety.
Flameproof enclosure type (d): Electric equipment with an explosion proof external shell. It can conceal ignited explosive gas mixture within the shell. The shell can contain the explosion pressure of the explosive gas mixture, and can prevent the blast from spreading to the surrounding explosive mixture.
Intrinsic safety type (ia, ib): Electric circuit and equipment, when under standard experimental conditions, spark and thermal effect produced under normal circumstances will not ignite the explosive mixture. Explosion proof electric equipment has a protruding “Ex” symbol on a distinctive place of the shell.
Section 4: Principle of selecting Ex proof equipment
At the explosion hazardous zone, selection of Ex proof electric equipment must be based on the consideration of the grades of the location, classification, grades and groups of explosion hazardous substances. At the Zone 0 location, electric equipment would not normally be installed, but if it is really necessary, you will only be allowed to install the intrinsic safety type equipment. At Zone 1 location, Ex proof equipment commonly used should be of intrinsic safety type and flameproof enclosure type. Zone 2 location's Ex proof equipment most commonly used is of the intrinsic safety type, flameproof enclosure type and increased safety type. In all the locations, it is not appropriate to use oil immersion type and powder-filled type equipment. The classification, grade and group of equipment being selected must not be lower than the grade and group of the explosive mixture at the location. When there are two types of explosive mixture in the same location, select equipment that uses a higher danger classification grade and group.
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