mechanical seal document describing types and how sealing action taking place in mechanical seal.
Mechanical seal practice
Full description
Selos Mecanicos
Understanding of Mechanical Seal in a pump
Improving Mechanical Seal Life
Deskripsi lengkap
investigate on properties of materials in m seals
Describes how to replace pump mechanical seal
problemas con sellos
API 571 Part 1Full description
Selection guidelines for double mechanical seals for pumps
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page Page 1 of 11 11
• Home • Contact Us Enter search keyword
Mechanical Engineering 4 UOnline Club For Mechanical Engineers
• • • • • • •
Auto AutoMo Mobi bile le Design Latest Latest Techno Technolog logy y Materi Material al Scienc Sciencee Stud Studen entt Res Resou ourc rces es » Techni Technical cal Stuff Stuff Videos
Categorized | Technical Stuff
API Mechanical Mechanical Seal Flushing Flushing Plan Plan – Part 1 Posted on 12 June 2011. Tags: API Mechanical Seal Flushing Plans, API plans, flushing plans, seal flushing 0
Ads by Google
Mechanical Seal
Pump Seal
Hand Water Pump
Heat Pump Costs
Why flushing is required? In mechanical seal heat is generated between the rotating and stationary seal face. If more amount of heat is generated between the faces cause the mechanical seal failure. In order to avoid the seal failure flushing fluid is injected between the seal face. There are different types of flushing plans used depend upon the conditions. These are following condition for selecting suitable mechanical seal flushing plan for both the supplier and vendor. • • • •
Nature of working working fluid (pumping (pumping fluid)such fluid)such as toxic, toxic, corrosiveness, corrosiveness, hazards chemicals. chemicals. Suspended solid particles particles in in the pumping fluid. Temperatu Temperature re of pumping pumping fluid fluid Vapour Vapour pressur pressuree of pumpin pumping g fluid fluid
API Plans: They are various types of flushing plans used in most of the industrial pumps. Now we see the API standard plans in detail. detail.
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page 2 of 11
API PLAN 02
In this mechanical seal plan the dead-ended seal chamber with no flush line arrangement. In which the pumping fluid pass through the back of impeller and fill the seal chamber. There by the seal faces were cooled. The pressure in the seal chamber is controlled by the expeller at the back of the impeller. In the case of moderate temperature services large bore open throat seal chamber is used. On the other hand for high temperature services cooling jacket seal chamber is used. Process fluid must have adequate boiling point margin to avoid vaporization between the seal faces. Often used in combination with steam quench Plan 62.
API Flushing Plan 02 Advantages: • Simple no environmental controls • Economic design of pump Disadvantages: • The plan only used for clean fluids • Pump back clearance is very important because change in back clearance cause change in seal chamber pressure. • Increase in throttle bush clearance also cause change in seal chamber pressure. API PLAN 11
Seal flush is taken from the pump discharge through an orifice. The function of orifice is to regulate the flow rate of flushing fluid to the seal chamber. In this plan use an orifice with a minimum 3 mm diameter based on the calculate flow rates to size orifice to adequate seal chamber flow. The flush fluid is injected directly over the seal faces with piping at 12 O clock position. In multistage pumps we get the flushing from the most convenient pump area.
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page 3 of 11
API Flushing Plan 11 Advantages: • Flushing fluid taken from the discharge, hence increase seal chamber pressure and allow the fluid with less vapour margin Disadvantage: • Used for clean fluid • Typical failure mode is a clogged orifice – check temperatures at pipe ends API PLAN 13
In this mechanical seal plan the flushing fluid enter the seal chamber from the back of the impeller. In which the seal chamber pressure is normally 1 to 1.5 times greater than the suction pressure. Hence it is re-circulating the flushing back to the pump suction. This type of flushing plan is mostly used in vertical pumps and continuous seal chamber venting is also provided. There by seal chamber heat is removal. In the case of moderate temperature fluids with moderate solids vent piping loop prior to starting vertical pumps. The size of orifice is determined by calculating the flow rates of fluid to the seal chamber normally the size of an orifice with a minimum 3 mm diameter is used in most of the industrial pumps.
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page 4 of 11
API Flushing Plan 13 If the seal chamber pressure is very high then it indicates that to select the proper orifice and throat bushing sizing. Typical failure mode is a clogged orifice – check temperatures at pipe ends Advantages: • Used for fluid which contain moderate solid particles Disadvantage: • Due to the presence of solid particles, orifice clogging is takes place this leads to seal failure. • Only used for vertical pumps API PLAN 14
In this mechanical seal flushing plan the fluid from discharge and recirculation back to the pump suction with orifices. This type of flushing plan is the combination of Plan 11 and 13 there by the seal chamber heat is removed. Increase seal chamber pressure and fluid flow rate is determined by the seal chamber inlet and outlet orifice. This type of seal plan is used on vertical pumps and Clean fluids at moderate temperatures. Increase boiling point margin of flushing fluid with proper orifice and throat bushing sizing. Flush should be directed over seal faces, Vent piping loop prior to starting vertical pumps
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page 5 of 11
API Flushing Plan 14 API PLAN 21
This type of mechanical seal plan is used for the flushing fluid with high temperature. This plan is similar to API plan 02 but it consisting of circulation ring for circulates the flushing fluid to the heat exchanger to reduce the temperature of the flushing before it reach the seal face. This type of flushing plan is used for high temperature service typically less than 177 oC. If reduce fluid temperature to increase vapour margin.
API Flushing Plan 21
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page 6 of 11
If the flushing fluid is over 80 oC, Seal cooler and piping must have air vents at highest elevation. Venting the seal chamber before starting the pump is very important because to avoid the dry run of mechanical seal. Calculate the flow rates to size an orifice for adequate seal chamber flow Increase boiling point margin with proper orifice and throat bushing sizing. Regularly monitor device inlet and outlet temperatures for signs of clogging or fouling API PLAN 23 This mechanical Seal flush plan is similar to API plan 11 the only difference is the fluid from the pump discharge is cooled by a cooler before the seal chamber as shown in the figure. This is the standard flush plan for hot water services such as used in boiler feed water pump. Efficient seal cooling with low cooler duty increase fluid vapour margin. This plan is used for high temperature service, hot hydrocarbons and Boiler feed water and hot water over 80 oC.
API Flushing Plan 23 Seal cooler and piping must have air vents at highest elevation. The piping arrangement is shown below.
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Page 7 of 11
Piping System of Plan 23
Seal chamber requires close clearance throat bushing to isolate hot process fluid from the cold seal chamber flushing fluid. Regularly monitor cooler inlet and outlet temperatures for signs of plugging or fouling. API PLAN 31
In this type mechanical seal flush plan is used for the pumping fluid consisting of solid particles. The flushing fluid from pump discharge is passing through a cyclone separator for separating the suspended solids from the pumping fluid. Centrifuged solid particles are returned to pump suction from the cyclone separator. Seal chamber heat is flushed by the fluid from the cyclone separator. This type of flushing plan is used for dirty or contaminated fluids, water with sand or pipe slug etc.., Cyclone separator works best on solids with a specific gravity twice the process fluid. Seal chamber pressure must be nearly equal to suction pressure for proper flows. The piping should not include an orifice and is not expected to vent the seal chamber.
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
API Flushing Plan 31 Disadvantage: • The solid particles density must at least twice the pumping fluid density. • Very close throttle bush clearance to be maintained.
Enter Your Mail Address
.
• Post to Facebook 3 3 Send
Like
3 people like this.
Page 8 of 11
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
You Like This
Characteristic Curve Of Centrifugal Compressor
API Mechanical Seal Flushing Plan-Part 2
Mechanical Seal Failure and Preventing Methods - Part 1
Basic Principle Of Deaerator and Deaeration Anti-Lock Braking System (ABS) in Bikes API Mechanical Seal Flushing Plan-Part 2 ←
→
Leave a Reply Name (required) Mail (will not be published) (required) Website
Submit Comment
Basic Of Anti-Friction Bearings Fit
Page 9 of 11
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Follow Or Fan Us Mechanical Engineering 4u on Facebook Like
1,081 people like Mechanical Engineering 4u.
Saleem
Ashish
Faheem fi az Prabhansh u
Genesis
Vaghela
Ku nal
S urendar
Sanket
Somu
Subscribe Us @
Recent Posts • • • • • • • • • •
Basic Of Galvanic Corrosion What is electrodes coating Basic Principle Of Deaerator and Deaeration What is Austenitic Stainless Steel – Part 1 Carbon Base Nano-materials and Device Conference Video of Crude oil Exploration to petrol production How Differential Gear Mechanism working in Automobile-Video Engine Emission Control System in Automobile Soot Blowers for Soot cleaning in Boilers European Solar Thermal Energy Conference
Page 10 of 11
API Mechanical Seal Flushing Plans-Part 1 | Mechanical Engineering 4 U
Login/Register Username: Password: Remember me Login »
