PIPING AND T PIPING ANKAGE ANK AGE TANKAGE DESIGN
PIPING AND TANKAGE DESIGN-GENERAL SESSION-I TANKAGES-DESIGN ASPECT
SESSION-II PIPING-DESIGN ASPECT
SESSION-III TANK FARM INSTRUMENTATION AND FIRE PROTECTION
SESSION-IV TANKAGES-OPERATION & SAFETY
SESSION-I
TANKAGES-DESIGN ASPECT
STORAGE PHILOSOPHY DEVELOP STORAGE PHILOSOPHY FOR
- FEED STORAGE - INTERMEDIATE FEED STORAGE - FINISHED PRODUCT STORAGE FEED STORAGE - RECEIVING MODE SHIPMENT PIPELINE ANY OTHER MODE - OPERATIONAL AND MAINTENANCE REQUIREMENT - NO. OF TANK AND CAPACITY OF EACH TANK
STORAGE PHILOSOPHY
INTERMEDIATE STORAGE - OPERATING PHILOSOPHY PHILOSOPHY & FLEXIBILITY - EMERGENCY SHUTDOWN -
TURN AROUND REQUIREMENT
FINISH PRODUCT STORAGE - OPERATIONAL REQUIREMENT - MODE OF DISPATCH
-
SHUTDOWN REQUIREMENT OPTIMIZATION/PREMIUM OPTIMIZATIO N/PREMIUM GRADE INTERMEDIATE STORAGE
DESIGN BASIS
TYPE OF TANK USED FOR STORAGE IS BASED BASED ON ON PROPERTIES LIKE -
FLASH POINT AND VAPOUR PRESSURE POUR POINT
-
REACTIVITY AND CONTAMINA CONTAMINATION TION CONTAMINAT ION
STORAGE TANKS ARE CLASSIFIED AS ATMOSPHERIC ATMOSPHERIC TANK (API-650) -
LOW PRESSURE TANK (API-620) HIGH PRESSURE STORAGE (ASME, BS)
-
REFRIGERATED STORAGE
DESIGN BASIS
ATMOSPHERIC TANK DESIGN PRESSURE UP TO 150MM OF H2O VAPOUR PRESSURE LESS THAN – 10 PSIA LOW PRESSURE TANK NORMALLY PRESSURE ABOVE 10 PSIA BUT LOWER THAN 15 PSIG (30 PSIA) AT MAX. OPERATING TEMP. THESE ARE NORMALLY BLANKETED TANKS HIGH PRESSURE STORAGE. VAPOUR PRESSURE ABOVE IS PSIG AT AVERAGE AMBIENT TEMP. THESE COMES UNDER PRESSURE VESSEL. TYPICALLY OVER GROUND PRESSURE VESSEL ARE BULLET, MOUNDED BULLET, HORTON SPHERES.
DESIGN BASIS
REFRIGERATED STORAGE -
-
THESE ARE LOW TEMPERATURE STORAGE TO STORE LIGHT HYDROCARBON.
STORAGE TEMP MAINTAINED TO KEEP VAPOUR PRESSURE AT ATMOSPHERIC PRESSURE / LOWER THAN ATMOSPHERIC.
DESIGN CRITERIA DESIGN GUIDELINE MINIMUM THREE OR FOUR TANK (EXCEPT INTERMEDIATE FEED STORAGE) STORAGE) FIXED UP CAPACITY OF EACH TANK. IN MARKETING TERMINAL RECEIPT MODE IS IMPORTANT FOR DECIDING TANK CAPACITY. - STORAGE OF EACH PRODUCT 7 TO 15 DAYS BASED ON REQUIREMENT. - OPERATION TO BE SUSTAINED WHILE ONE OF THE TANK IS OUT FOR MAINTENANCE. -
DESIGN CRITERIA
TYPE OF TANK FOR DIFFERENT PRODUCT ARE SELECTED TO MINIMISE LOSSES TO MEET ENVIRONMENTAL REGULATION SAFETY QUALITY OPERABILITY
ATMOSPHERIC TANKS FLOATING ROOF CONE ROOF/ N2 BLANKETED CONE ROOF -
CONE CUM FLOATING ROOF
DESIGN CRITERIA
FLOATING ROOF TANK -
TANKS ARE DESIGNED AS PER API-CODE-650 USED FOR LIGHT / MIDDLE DISTILLATE.
NOMINAL CAPACITY, STORED CAPACITY, NET CAPACITY CAPACITY REQUIREMENT. REQUIREMENT. DESIGN PRESSURE -
VENTING OUT/BREEDING IN DURING PUMPING IN/ OUT, CHANGE IN AMBIENT CONDITIONS EMERGENCY VENTING REQUIREMENT
DESIGN CRITERIA -
CORROSION ALLOWANCE. ROOF SUPPORT. ROOF DESIGN. MANHOLES AND CLEAN OUT DOORS. SEALING ARRANGEMENT BETWEEN PERIPHERY OF ROOF AND TANK SHALL.
DESIGN CRITERIA -
-
ROOF DRAINS / EMERGENCY ROOF DRAINS ROOF TO SHALL BONDING TO AVOID CHARGE ACCUMULATION. CENTERING AND ANT ROTATION GUIDES ARE PROVIDED TO COUNTER LATERAL FORCES (LADDER, WIND, RAIN WATER).
DESIGN CRITERIA
CONE ROOF TANK/ CONE CUM FLOATING ROOF TANK
- OPEN VENT OR N2/INERT GAS BLANKETED TANKS DESIGNED UNDER API-650. - NORMALLY OPEN VENT CONE ROOF TANKS ARE USED FOR HEAVY HYDROCARBON PRODUCT. FUEL OIL, VR, HEAVY Y GAS OIL, BITUMEN, ETC. STORED IN OPEN VENT TANK. N2 BLANKETED TANKS ARE USED FOR INTERMEDIATE FEED STORAGE WHERE DEGRADATION OF PRODUCT CAN CAUSE PROBLEM IN DOWN STREAM UNIT TANKS STORING TOXIC MATERIALS LIKE BENZENE SOUR WATER ETC.
DESIGN CRITERIA -
OPEN VENT CONE ROOF TANKS ARE USUALLY DESIGNED FOR FULL OF LIQ. OR WATER.
-
N2 BLANKETED TANK ARE DESIGNED FOR A MAX. PRESSURE OF 150MM OF WATER. COLUMN. IN POSITIVE SIDE AND 50 MM IN THE VACUUM SIDE.
-
THESE TANKS ARE DESIGNED WITH NORMAL VENT AS WELL AS EMERGENCY VENT.
DESIGN CRITERIA
FOR N2 BLANKETED TANKS PVRV IS PROVIDED IN PLACE OF NORMAL VENTING.
SET PRESSURES OF PVRV. EMERGENCY VENT SHELL BE WITHIN THE DESIGN LIMIT.
DESIGN CRITERIA
N2 BLANKETED SYSTEM
DESIGN CRITERIA
CONE CUM FLOATING ROOF TANK -
THESE TANKS ARE USED FOR STORING TOXIC PRODUCT AND PRODUCT WITH STRINGENT QUALITY (E.G. BENZENE, ATF)
-
NITROGEN OR INERT GAS BLANKETING MAY BE PROVIDED IN CASE OF REQUIREMENT REQUIREMENT
TANKS WITHOUT NITROGEN/ INERT GAS BLANKETING BLANKETING ARE PROVIDED WITH CIRCULATING VENT JUST BELOW THE CONE ROOF
DESIGN CRITERIA TANKS WITH ELEVATED TEMPERATURE USED FOR CONGEALING SERVICES. -
POUR POINT, VISCOSITY, AUTO IGNITION TEMP. OF MATERIAL DECIDES STORAGE TEMPERATURE PRINCIPLE OF DESIGNING HEATING ARRANGEMENT IS TO ARGUMENT HEAT LOSS. -
THESE TANKS ARE INSULATED TO MINIMISE THE HEAT LOSS.
DESIGN CRITERIA -
STEAM COILS ARE USED TO SUPPLY HEAT.
-
NORMALLY STEAM PRESSURE 3 TO 5 USED.
-
KG/CM2G IS
CRUDE/BENZENE TANKS ARE ALSO SOMETIMES CRUDE/BENZENE PROVIDED WITH HEATING COIL. BUT NOT INSULATED TEMPERATURE NORMALLY MAINTAINED ABOUT 10° ABOVE POUR POINT.
DESIGN CRITERIA
LOW PRESSURE TANKS
LOW PRESSURE TANK DESIGN GUIDELINES ARE PROVIDED IN API-620.
THESE TANKS ARE NORMALLY N2/ INERT GAS GAS BLANKETED.
MAX DESIGN PRESSURE IS 1 KG/CM2G KG/CM2G AND AND VACUUM VACUUM UP UP TO 50 MM OF WATER
ALL OPERATING REQUIREMENT REQUIREMENT IS SIMILAR TO N2 BLANKETED ATM. STORAGE TANKS.
DESIGN CRITERIA HIGH PRESSURE STORAGE
HIGH PRESSURE STORAGE ARE PRESSURE VESSELS DESIGN GUIDELINES ARE AVAILABLE IN ASME, API, BS ETC. NORMALLY LPG, PROPANE, PROPYLENE, BUTANE ETC. REQUIRES PRESSURE VESSEL. SPHERES, BULLET OR MOUNDED BULLETS ARE TYPICAL STORAGES. MAJOR HAZARDS FROM THESE STORAGES ARE FLASH FIRE, VAPOUR CLOUD EXPLOSION AND FIRE BALL OR BLEVE.
DESIGN CRITERIA
CHANCES OF FIRE BALL OR BLEVE IS ELIMINATED USING MOUNDED STORAGE SPECIAL REQUIREMENT ARE : SAFETY RELIEF VALVE. AUTOMATIC WATER SPRINKLER ACTUATE BY GAS FIRE DETECTORS. REMOTE OPERATED ISOLATION VALVES (FIRE RESISTANT). MINIMISING NO OF LIQUID NOZZLES / FLANGES. OVERFILLING PROTECTION
OR
DESIGN CRITERIA MOUNDED STORAGE -
-
-
OVER GROUND STORAGE COVERED WITH MOUND OF EARTH. MOUND SHALL BE ACCESSIBLE TO FIRE TENDER. TENDER. DESIGN GUIDELINES BY ASME SEC VIII OR BS-5500. SINGLE CODE TO BE ADOPTED FOR DESIGN, FABRICATION, INSPECTION, TESTING AND INSTALLATION. SURFACE COATING CATHODIC PROTECTION TO BE PROVIDED.
DESIGN CRITERIA -
-
-
-
PROVISION TO DRAIN OUT COMPLETELY. MOUNDED BULLET CAN HAVE EITHER INTANK PUMP FOR EXTERNAL PUMP. A SINGLE NOZZLE PROVIDED FOR USING EXTERNAL PUMP. ROV (FIRE SAFE TYPE) FOR LIQUID LINE/ VAPOUR BALANCE LINE. TWO PSV OF 30% EACH (MINIMUM) FOR FIRE CASE. FIRE WATER SPRAY IN EXPOSED AREA HYDRANT AND MONITOR COVERAGE.
SESSION-II
PIPING-DESIGN ASPECT
OFFSITE PIPING DESIGN BASIC DATA REQUIRED
OVERALL PLOT PLAN SHOWING - LOCATION OF TANKS. - PUMP HOUSE LOCATION. - LOCATION OF PROCESS UNIT. - AREA TOPOGRAPHY. - BATTERY LIMIT CONDITIONS. - PROPERTIES OF INDIVIDUAL STREAMS. - ESTIMATION OF EQUIVALENT PIPE LENGTH. - PRESSURE REQUIRED AT DESTINATION.
OFFSITE PIPING DESIGN
-
LINE SIZING CRITERIA ACCEPTABLE VELOCITY RANGE
ACCEPTABLE PRESSURE DROP PER KM OF EQUIVALENT LINE LENGTH. ACCEPTABLE VELOCITY RANG E FOR WATER, LIGHT HYDROCARBON, HEAVY HYDROCARBON, STEAM, VAPOURS ETC. ARE AVAILABLE FROM DIFFERENT SOURCES.
RECOMMENDED VELOCITY AND PRESSURE DROP FOR CS LIQUID LINE
PRESS. GENERAL RECOM. LAMINAR FLOW PUMP SUCTION BOILING LIQUID NON-BOILING LIQUID
RECOM. VELOCITY
MAX ALLOW
1.5-4.5 1.2-1.5
8.8
0.6-1.8 1.2-2.5
1-1 2-2
RECOMMENDED VELOCITY AND PRESSURE DROP FOR CS LIQUID LINES RECOM. VELOCITY
MAX ALLOW
PRESS. PUMP DISCHARGE FLOW, M3/HR 0-55 55-160
1.8-2.5 2.5-3.0
13.2 8.8
MORE THAN 160
3.0-4.5
4.4
GRAVITY RUN LINES
0.3-2.5
0.88
RECOMMENDED VELOCITY AND PRESSURE DROP FOR CS VAPOUR LINES
RECOM. VELOCITY
MAX. ALLOWABLE PRES. DROP
ABOVE 35 14-35
V= (3 TO 24)/ d 1/3 d=DENSITY
4.4 3.3
10-14 3.5-10
KG/M3
1.32 0.66
0-3.5 SUB-ATM. (VACUUM) (VACUUM)
0.33 0.22
RECOMMENDED VELOCITY AND PRESSURE DROP FOR CS STEAM SERVICES RECOM. MAX VELOCITY GENERAL RECOMMENDATION MAXIMUM SATURATED 60.0 SUPERHEATED 75.0 STEAM PRESSURE KG/CM2G 0-3.5 0.55 3.5-10 1.1 10-20 2.2 ABOVE 20 3.3
ALLOW
PRESS.
RECOMMENDED VELOCITY AND PRESSURE DROP FOR STEAM SERVICES RECOM. VELOCITY
MAX ALLOW
PRESS. HIGH PRESSURE STEAM LINES SHORT (LENGTH LESS THAN 180 M) LONG LENGTH (MORE THAN 180 M) SHORT LEADS
2.2 1.1 5.5
OFFSITE PIPING DESIGN SPECIAL CONSIDERATION
FOR SIZING PUMP SUCTION LINE VELOCITY RANGE OF 0.8 TO 1.5 M/S IS TAKEN FOR ALL HYDROCARBON/WATER.
PRESSURE DROP ESTIMATION FOR CONTROL VALVES, FLOW METERS, STRAINERS ETC.
SPECIAL REQUIREMENT REQUIREMENT FOR PUMP SUCTION LINE, TANKAGE MANIFOLD VALVING & PUMP MINIMUM FLOW CIRCULATION CIRCULATION
OFFSITE PIPING DESIGN TYPICAL INPUT FOR SIZING OF LIQUID LINE
INPUT DATA REQUIRED NORMAL/RATED FLOW REQUIREMENT -
B/L CONDITION CONDITIONS, S, (PRESSURE, TEMPERATURE) TEMPERATURE) AT SUPPLY AND DESTINATION FLUID PROPERTIES NAMELY, DENSITY & VISCOSITY. ESTIMATE REQUIREMENT LENGTH OF PIPE BASED ON PLOT PLAN. SELECT A PIPE LINE SIZE BASED ON RATED FLOW WHICH MEETS THE VELOCITY CRITERIA (START WITH MINIMUM PIPE SIZE WHICH MEETS THE VISCOSITY CRITERIA).
OFFSITE PIPING DESIGN
CALCULATE Re NO. USING Re = 3.54 X 10E4Q/ µD WHERE,
Q = RATED FLOW M3/HR D=ID OF THE PIPE IN CM
µ = VISCOSITY IN CS ESTIMATE FRICTION FACTOR USING GRAPH
OFFSITE PIPING DESIGN
CALCULATE PRESSURE DROP USING ∆
P = (63.7 X100) Q2 f d --------
D5 WHERE d = SPECIFIC GRAVITY WITH RESPECT TO WATER ∆ P = PRESSURE DROP/KM OF PIPE LENGTH f= FRICTION FACTOR
PRODUCT BLENDING -
-
-
-
ESTABLISH PRODUCT SPEC. AS PER REQUIREMENT FOR DIESEL; 5%, DENSITY FLASH POINT, POUR POINT. STREAM THAT ARE REQUIRED TO BE BLENDED ITS PROPERTIES. DESIGN, OPERATING PARAMETER AND ALTERNATE DESTINATION OF EACH STREAM. DEVELOP BLENDING SCHEME
PRODUCT BLENDING
BLENDING SCHEMATIC
SOME OF OPERATIONAL ASPECTS CONSIDERED IN PIPING DESIGN FROM OFFSITES 1)
2)
3)
4)
PIPING DESIGN TEMPERATURE, 65°C FOR WHILE OIL/LIGHT HYDROCARBONS AND 150°C AND ABOVE FOR HEAVY OIL. DO NOT PROVIDE VALVES IN OFFSITE PIPE RACK EXCEPT CLOSE TO PUMP HOUSE AND TANKAGE MANIFOLD. ANY FACILITIES REQUIRE CONSTANT MONITORING TO BE LOCATED CLOSE TO PUMP HOUSE (DOSING SYSTEM HEATERS ETC.). PROVIDE SEPARATION DISTANCE TO SEGREGATE PUMPS OF PRESSURIZED LIQUID, WHITE OIL AND BLACK OIL.
SOME OF OPERATIONAL ASPECTS CONSIDERED IN PIPING DESIGN FROM OFFSITES 5)
6)
7)
8)
REMOTE OPERATED (FIRE SAFE) VALVES ARE PROVIDED TO ISOLATE GANTRY IN CASE OF EMERGENCY. ADEQUATE EXPANSION PROVISION IS KEPT FOR PIPING DESIGN ABOVE 150°C. OPERATING VALVES FOR TANKAGES ARE KEPT OUTSIDE DYKE AREA. MEANS OF POSITIVE ISOLATION IS KEPT FOR TANKS REQUIRING EXCISE FORMALITIES.
PRODUCT DISPATCH DESIGN GUIDELINES -
-
-
-
DISPATCH BY PIPELINE, RAIL TANKER, ROAD TANKER. PIPELINE MAY BE FOR CRUDE, BLACK OIL, OR WHITE OIL PRODUCTS (MULTIPRODUCT). RAIL GANTRY SHOULD BE SEPARATE FOR WHITE OIL, BLACK OIL AND PRESSURIZED LIQUID (LPG). ESTIMATE ESTIMATE QUANTITY QUANTITY OF OF PRODUCT PRODUCT TO BE DISPATCH BY EACH MODE. EACH PRODUCT WILL HAVE ITS SOON LOADING HEADER, METERING METERING FACILITIES FACILITIES AND LOADING ARM. FOR ROAD LOADING EACH PRODUCT HAVE SEPARATE LOADING BAYS.
PRODUCT DISPATCH DESIGN GUIDELINES -
-
-
-
-
PROVISION TO BE KEPT FOR UNLOADING OF SICK WAGON/TANKER (GRAVITY DRAIN WITH UNDER GROUND VESSELS). ESTIMATE RACK FILLING/ROAD TANKER LOADING LINE INCLUDING PLACEMENT, CONNECTION, DISCONNECTION. ESTIMATE TOTAL LOADING HOURS AVAILABLE IN A SINGLE DAY. (FOR ROAD LOADING) AND NO. OF DAYS AVAILABLE FOR LOADING IN A CALENDAR YEAR. CALCULATE THE HEAD REQUIRED FOR LOADING PUMPS AND FIX UP NO. OF PUMPS POWER REQUIRED USING PROPERTIES OF FLUID. FIXED UP NO. OF ROAD LOADING BAYS REQUIRED.
SESSION-III TANK FARM INSTRUMENTATION & FIRE PROTECTION
TANK LEVEL MEASUREMENT -
-
-
-
MINIMUM TWO LEVEL INST. SERVO TYPE AND RADAR TYPES GENERALLY USED. INSTRUMENTS FOR MEASURING DENSITY AND WATER CUT ARE ALSO SPECIFIED ALONG WITH LEVEL INSTRUMENT MECHANICAL FLOAT TYPE SOMETIMES USED FOR CLEAN SERVICES TO GENERATE GENERATE ALARM. ALARM. DP TYPE ARE USED NORMALLY FOR PRESSURIZED LIQUID E.G. LPG PROPANE/PRO PROPANE/PROPYLENE PYLENE ETC. ALARMS ARE PROVIDED FOR HIGH AS WELL AS LOW LEVELS.
FLOW MEASUREMENT ORIFICE METER PD METER
-
LOW ACCURACY HEAVY OIL
TURBINE METER ULTRA SONIC
-
LIGHT/MED. OIL LIGHT/MID/GAS
PITOT TUBE
-
LOW ACCURACY USED FOR LARGE DIA PIPE
GROUPING OF TANKS AND DYKE AREA
GUIDELINES PROVIDED BY NFPA/OISD -
PREFERABLE TO STORE CLASS-A, CLASS-B AND CLASS-C PRODUCT IN SEPARATE DYKE.
-
MAXIMUM VOL IN A SINGLE DYKE IS 1,20,000 FOR FLOATING ROOF AND 60,000 M3 FOR ROOF TANKS.
M3 CONE
GROUPING OF TANKS AND DYKE AREA
SOME OF CRITICAL REQUIREMENT ARE: -
DYKE VOLUME, DIKE HEIGHT NO. OF ROWS AND ROAD APPROACH
-
FIRE WALL FOR EACH TANK. TANK HEIGHT DETERMINE BY SOIL BEARING CAPACITY. DRAINAGE SYSTEM (RAIN WATER/TANK DRAIN WATER/ ROOF DRAIN WATER). PIPING IN THE DYKE AREA
-
PUMP STATION
-
-
FIRE PROTECTION FACILITIES
FIRE WATER SYSTEM STORAGE, PUMPING, FIRE HYDRANT & DISTRIBUTION NETWORK. DESIGN CRITERIA -
-
ONE MAJOR FIRE 4 HOURS STORAGE, MIN. 2 STORAGE TANKS. 100% DIESEL DRIVEN (6 HOURS CONTINUOUS RUNNING) 50% EXTRA CAPACITY MIN. 7 KG/CM2G PRESSURE AVAILABLE AT HYDRANT POINT
FIRE PROTECTION FACILITIES -
FIRE WATER STORAGE MIN. 30 M AWAY. HYDRANT NETWORK.
-
SPACING OF HYDRANT AND MONITORS AND LOCATE OUTSIDE DYKE AREA.
-
NETWORK NORMALLY KEPT PRESSURIZED. DESIGN WATER FLOW RATE
-
COOLING THE TANK ON FIRE 3 LPM/M2
-
OTHER TANKS AT R+30M WITHIN IN THE DYKE AREA 3 LPM/M2.
FIRE PROTECTION FACILITIES -
R+30M BUT NOT IN SAME DYKE 1 LPM/M2.
-
WATER FLOW REQUIREMENT FOR APPLYING FOAM FOR THE SINGLE LARGEST TANK.
-
ALTERNATE CALCULATION IS OPERATION OF 4 HYDRANTS AND 1 MONITOR SIMULTANEOUSLY.
FOAM SYSTEM
FIXED FOAM SYSTEM CONSIST OF -
WATER SUPPLY FOAM CONCENTRATE TANK
EDUCTOR AND SUITABLE PROPORTIONATING EQUIPMENT FOAM MAKER VAPOUR SEAL BOX. -
FIRE DETECTION SYSTEM TO ACTIVATE THE FOAM SYSTEM.
FOAM SYSTEM
SEMI FIXED FOAM SYSTEM - SUPPLY FOAM SOLUTION THROUGH MOBILE FOAM TENDER AND CONNECTED FIXED FOAM MAKERS CUM VAPOUR SEAL BOX FOR CONE ROOF TANK OR FOAM MAKER AND FOAM POWDER IN CASE OF FLOATING ROOF TANK. MOBILE SYSTEM - SUPPLY THROUGH MONITOR / TOWER USING FOAM TENDER.
FOAM SYSTEM SPECIAL FOAM INJECTION SYSTEMS
CONE ROOF SUBSURFACE FOAM INJECTION THROUGH BACK PRESSURE FOAM SUPPLY SYSTEM.
HIGH
FLOATING ROOF AUTOMATIC ACTUATED (THROUGH LINEAR HEAT DETECTOR) FOAM FLOODING SYSTEM (FLOATAFOAM OR EQUIVALENT). RIM SEAL FOAM POURER
LEAK AND FIRE DETECTION SYSTEM -
GAS DETECTORS PROVIDED WHERE LEAKAGE CAN CAUSE VAPOUR / GAS RELEASE. RELEASE.
-
HYDROCARBON DETECTORS, H2S DETECTOR, CHLORINE DETECTORS USED IN REFINERY.
-
FIRE DETECTORS ARE USED WHERE LEAKAGE OF HOT MATERIALS MATERIALS CAN RESULT AUTO IGNITION.
-
THESE ARE HEAT DETECTORS OR ULTRA VIOLATE RAY DETECTOR.
SESSION-IV
TANKAGES-OPERATION & SAFETY
SAFETY FACTORS CONSIDERED DURING DESIGN SAFETY OF EVERY TANK IS OF UTMOST IMPORTANCE. FAILURE OF ANY TANK WILL LEAD TO PROPERTY LOSS AND MAY AFFECT SMOOTH OPERATION OF UNITS. AT THE EXTREME CASE IT CAN RESULT HAZARDOUS CONSEQUENCES IN CASE OF FIRE. IMPORTANT SAFETY FACTORS CONSIDERED DURING DESIGN; x DESIGN CODE x FINALIZATION OF CAPACITY x SELECTION OF TYPE OF TANKS x PLOT PLAN LOCATION x VENTING x INSTRUMENTATION x FIRE PROTECTION FACILITIES x MISCELLANEOUS SAFETY POINTS
SAFETY FACTORS CONSIDERED DURING DESIGN
SELECTION OF TYPE OF TANKS: TYPE OF TANK TO BE DECIDED CONSIDERING THE FOLLOWING SAFETY POINTS:
VAPOUR LOSS AND HYDROCARBON EMISSION FIRE HAZARD TO MEET STRINGENT WATER SPECIFICATION TO MEET STRINGENT ENVIRONMENT SPECIFICATION PRODUCT CONTAMINATION WITH INGRESS AIR
SAFETY FACTORS CONSIDERED DURING DESIGN
PRODUCT HAVING HIGH VAPOUR PRESSURE AND LOW FLASH POINT ARE GENERALLY STORED IN FLOATING ROOF TANKS OR DOME ROOF TANK TO REDUCE VAPOUR LOSS, HYDROCARBON EMISSION AND FIRE HAZARD. PRODUCT HAVING LOW VAPOUR PRESSURE AND HIGHER FLASH POINT STORED IN CONE ROOF TANKS. TO MEET STRINGENT WATER SPECIFICATION IN THE PRODUCT OR TO MEET STRINGENT ENVIRONMENT SPECIFICATION , PRODUCT STORED IN CONE CUM FLOATING ROOF TANKS . TO AVOID PRODUCT CONTAMINATION WITH INGRESS AIR TO AVOID POLYMERIZATION OF PRODUCT , NITROGEN BLANKETING TANKS IS CONSIDERED CONSIDERED..
SAFETY FACTORS CONSIDERED DURING DESIGN
VENTING : EACH TANK IS PROVIDED WITH SUITABLE VENT. TANK VENT IS TO BE SIZED AS PER API-2000. FOLLOWING PARAMETERS NEED TO BE CONSIDERED WHILE DESIGNING VENT; x x x
x
x
MAXIMUM PUMPING IN RATE OR RECEIPT RECEIPT RATE RATE MAXIMUM PUMPING OUT RATE OR DISPATCH RATE OUT BREATHING FROM THERMAL EXPANSION OF VAPORS CAUSED BY MAXIMUM INCREASE IN AMBIENT TEMPERATURE. IN BREATHING FROM THERMAL THERMAL CONTRACTION CONTRACT ION OF VAPORS CONTRACTION CAUSED BY MAXIMUM DECREASE IN AMBIENT TEMPERATURE. OUT BREATHING RESULTING FROM FIRE EXPOSURE
SAFETY FACTORS CONSIDERED DURING DESIGN HOWEVER , IN ADDITION TO THE ABOVE , SOME SPECIFIC CASES , WHICH CAN CAUSE OVERPRESSURE OR VACUUM IN TANKS , ARE ALSO TO BE CONSIDERED DURING VENT DESIGN. SOME OF THESE ARE EXPLAINED BELOW: x
x
x
FOR INERT GAS BLANKETED TANKS, THERE IS POSSIBILITY OF FAILURE OF PRESSURE CONTROLLER , RESULTING IN THE OVERPRESSURE. CHANGE IN TEMPERATURE OF FEED LIQUID TO TANK DUE TO IMPROPER COOLING IN THE UNIT LEADING TO OVERPRESSURE OF THE TANK. MECHANICAL FAILURE OF TANK HEATING COIL
SAFETY FACTORS CONSIDERED DURING DESIGN
MISCELLANEOUS SAFETY POINTS: x CORROSION ALLOWANCE : CORROSION ALLOWANCE SHOULD BE SPECIFIED BASED ON THE NATURE OF PRODUCT STORED , STORAGE TEMPERATURE, TEMPERATURE TEMPERATURE,, ITS IMPURITIES, AMBIENT CONDITION. x EARTHLING OF TANKS : EVERY STORAGE TANK , INCLUDING ITS ROOF AND ALL METAL CONNECTION SHOULD BE ELECTRICAL ELECTRICALLY LY CONTINUOUS AND EFFECTIVELY EARTHED. x FLAME ARRESTOR : CONE ROOF TANK HAVING OPEN VENT , STORING CLASS “A” PETROLEUM PRODUCT PREFERABLY BE PROVIDED WITH FLAME ARRESTOR.
SAFETY FEATURES PUMP IN/OUT ARE TO BE WITHIN THE DESIGN LIMIT PRODUCT RUNDOWN TEMPERATURE NEEDS TO BE MONITORED. HIGHER TEMPERATURE RESULT VAPOUR BEING RELEASED TO ATMOSPHERE CAUSING HAZARDS. DURING PUMPING OUT FLOATING ROOF LEGS TO BE AT LOWEST POSITION (NORMAL OPERATION). OPERATION). BREATHER VENT SOMETIMES PROVIDED WITH FLAME ARRESTOR ARE LIKELY TO PLUGGED, SPECIALLY FOR HEAVY MATERIALS WITH TANK HEATING ARRANGEMENT.
SAFETY FEATURES
-
-
-
-
TANKS WITH STORAGE TEMP. OF 80°C OR 140°C SPECIAL CARE TO BE TAKEN FOR BOIL OVER. SPECIALLY SPECIALLY DURING COMMISSIONING. COMMISSIONING. STATIC ELECTRICITY IS A MAJOR HAZARD DURING INITIAL FILLING OF TANKS. PRESSURE RELIEF VALVES TO BE TESTED EVERY YEAR TESTING & INSPECTION OF VESSEL/TANKS ONCE IN 5 YEARS. OPERATING AND MAINTENANCE MANUAL UPDATION
OPERATION OF STORAGE TANK
NORMAL OPERATION THE NORMAL OPERATION REQUIRED FOR STORAGE TANKS ARE TO RECEIVE PRODUCTS FROM PROCESS UNIT OR FROM OUTSIDE AND TRANSFER THEM FOR ONWARD ONWARD PROCESSING / DISPATCH BY PUMPS. WHILE DOING THE ROUTINE ROUTINE OPERATIONS , OFFSITE OPERATING PERSONNEL SHOULD TO TAKE FOLLOWING PRECAUTIONS: WHILE RECEIVING PRODUCT IN AN EMPTY T ANK, CARE EMPTY TANK, TANK, SHOULD BE TAKEN SO THAT THE FLOW VELOCITY AT THE TANK INLET DOES NOT EXCEED 1 M/SEC M/SEC UNTIL THE INLET IS IS COMPLETELY SUBMERGED. ADEQUATE CARE SHOULD BE TAKEN TO ENSURE THAT AT NO TIME A TANK IS FILLED BEYOND ITS SAFE FILLING HEIGHT. JET MIXING NOZZLE OR SIDE ENTRY MIXERS SHOULD NOT BE USED WITH LOW LEVEL IN THE TANK. THIS MAY PRODUCE STATIC CHARGE IN THE TANK.
GUIDELINES IN OPERATION WITH STORAGE TANK
DRAIN VALVES OF THE TANKS SHOULD NEVER BE LEFT OPEN / UNATTENDED. WHENEVER DRAINING IS TO BE DONE , OPERATOR SHOULD PERSONALLY PERSONALLY ATTENDED ATTENDED TO TO IF AND ENSURE THAT THE VALVE IS PROPERLY CLOSED AFTER THE NECESSARY DRAINING IS OVER.
GAUGE HATCH ON THE TANK TOP SHOULD NORMALLY BE KEPT CLOSED AS A MEASURE OF SAFETY AS WELL AS TO AVOID ENTRY OF RAIN WATER AND REDUCE LOSS OF PRODUCT DUE TO EVAPORATION.
TANKS WHICH ARE PROVIDED WITH STEAM STEAM HEATING HEATING COIL SHOULD BE REGULARLY CHECKED FOR CORRECT C ORRECT WORKING OF STEAM COILS AND STEAM TRAPS. TANK WITH LOW LEVEL SHOULD NOT BE CHARGED WITH HEATING STEAM UNLESS THE STEAM COILS ARE COMPLETELY SUBMERGED IN OIL.
GUIDELINES IN OPERATION WITH STORAGE TANK
PROPER TEMPERATURE SHOULD BE MAINTAINED IN TANK T ANK CONTAINING BLACK PRODUCT PR ODUCT TO AVOID CONGEALING PRO DUCT TO PROBLEM. FOR OPERATING FLOATING ROOF TANKS, SPECIAL CARE AS OUTLINED BELOW SHOULD BE TAKEN. − THE PONTOON/PAN SHOULD NOT BE ALLOWED TO REST ON THEIR THEIR LEGS UNDER UNDER NORMAL NORMAL CIRCUMSTANCES. CI RCUMSTANCES. CIRCUMSTANCES. − THE LIFTING OF THE PONTOON/PAN FROM ITS RESTING POINT SHOULD BE BE DONE SLOWLY ALLOWING ALLOWI NG IT TO ALLOWING FLOAT AS UNIFORMLY AS POSSIBLE. − TRANSFER OPERATIONS TO AND FROM THE TANKS SHOULD NOT BE DONE IN THE THE CRITICAL REGION OF OF THE PONTOON/PAN (PONTOON OR PAN NOT NOT FLOATING FLOATING FULLY) AS THE OIL ACCOUNTING WILL BE ERRONEOUS. − IN CASE OF FLOATING ROOF TANKS, T ANKS, ROOF DRAIN SHOULD NORMALLY BE SHOULD BE BE KEPT CLOSED CLOSED AND SHOULD OPENED IN CASE OF A RAIN FALL ENSURING THAT RAIN WATER DOES DOES NOT ACCUMULATE ON THE ROOF. ROO F. ROOF.
GUIDELINES IN OPERATION WITH STORAGE TANK
FOR OPERATI OP ERATING NG THE SIDE SIDE‑ENTRY MIXE MIXERS, RS, THE OPERAT ING FOLLOWING SHOULD BE CHECKED : − CHECK THAT THE MOTOR SHAFT IS REASONABLY FREE AND GREASING IS PROPER. − CHECK THAT THE MOTOR SHAFT COUPLING IS PROPERLY PROPE RLY SECUR SECURED ED AND COUPL COUPLING ING ‑GUARD IS IN PROPERLY SECURED POSITION. − ENERGIZE THE MOTOR AND CHECK THAT THE DIRECTION OF ROTATION IS ALL ALL RIGHT. RIGHT. − FLUSH AND RENEW OIL IN THE GEAR BOX. − CHECK THAT OIL LEVEL IN THE TANK IS SUFFICIENT FOR OPERATION OPERA TION OF THE SIDE‑ENTRY MIXE MIXER. R.. RUN THE OPERATION MIXER MIXER. − CHECK FOR UNUSUAL NOISE, VIBRATIONS AND RISE OF TEMPERATURE IN THE GEAR BOX AND MOTOR BEARINGS.
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