“Tank farm operations.”
TOPICS :TANK FARM OPERATION & GAUGING•TANK /SAMPLES TYPES & SAMPLING•DIPPING, DENSITY & TEMP. MEASUREMENT •PREPARATION OF OUTTURNS•OIL ACCOUNTING & LOSS CONTROL•PIPELINE LOSS/GAIN RECONCILATION
STORAGE TANKS
TYPE OF TANKS:MAINLY OF TWO TYPES:
•FLOATING ROOF TANKS ( FOR LIQUIDS WITH HIGH VAPOUR PRESSURES SUCH AS CRUDE OIL, MS)
- EITHER SINGLE DECK OR DOUBLE DECK
•FIXED ROOF TANKS ( FOR LIQUIDS SUCH AS HSD, SKO)
Floating Roof Tanks
• When the Tank is in operation, the Roof should always be in floating condition
• In resting or semi-floating condition, the tank should not be operated
• The seal should be checked periodically • The roof should also be checked periodically
(especially during Monsoon) to ensure that there is no water accumulation at the deck.
TANK BOTTOM
ANNULAR PLATES
SKETCH PLATES
LONG SEAMS
SHORT SEAMS
TANK SHELL
•SHELL PLATE IS OF VARYING THICKNESS THICKEST PLATE FOR THE LOWEST COURSE AND DECREASING THICKNESS FOR UPPER COURSES.•THE PLATES ARE ARRANGED SO THAT THERE IS AN OFFSET BETWEEN TWO VERTICALS•PLATES ARE FLUSH FROM TANK INSIDESO THAT I.D. OF THE TANK DOES NOT CHANGE.THIS ARRANGEMENT IS ALSO A MUST FOR THE FLOATING ROOF TANKS.
SHELL NOZZLES
•INLET NOZZLE•OUTLET NOZZLE•WATER DRAW OFF•PRODUCT DRAW OFF•CLEAN OUT DOOR•ROOF DRAIN•TANK STIRRER NOZZLES/ JET MIXER NOZZLES
INLET AND OUTLET NOZZLES
BOTTOM REINFORCEMENT PLATE
TANK INSIDE
R/F PAD
TANK INLET NOZZLE
TANK INSIDE
BOTTOM PLATE
TANK OUTLET NOZZLE
TANK BOTTOM
•BOTTOM PLATES USUALLY 0F 8 MM THICKNESS INCLUSIVE OF CORROSION ALLOWANCE•LAYING SHOULD BE SUCH THAT IT FACILITATES FLOW OF MUCK TOWARDS THE SLOPE (EITHER INWARDS OR OUTWARDS).•MINIMUM WIDTH IS RECOMMENDED TO BE 72 INCH•JOINED BY FULL FILLET WELDING•REINFORCEMENT PLATE IS RECOMMENDED TO BE WELDED WHERE INLET JET IMPINGES ON THE TANK BOTTOM
TANK ROOF
DOUBLE DECK FLOATING ROOF
•ROOF IS CONSTRUCTED ON TEMPORARY SUPPORTS ERECTED ON THE TANK BOTTOM•BOTTOM DECK IS KEPT AS FLAT AS POSSIBLE•THE TOP DECK PLATE, USUALLY OF 5 MM HAS SLOPE TOWARDSTHE ROOF DRAINS•THE SPACE BETWEEN THE TOP DECK AND BOTTOM DECK IS DIVIDED INTO A No. OF BOXES CALLED PONTOONS.•EACH PONTOON IS A LEAK TIGHT COMPARTMENT MADE FROM•CIRCUMFERENTIAL AND RADIAL BULKHEADS.•THE TOP DECK IS SUPPORTED ON RAFTERS AND TRUSSES. •EACH COMPARTMENT HAS A MANWAY FOR INSPECTION
TANK ROOF
ROOF DESIGN AND INSPECTION
THE DECK IS SO DESIGNED THAT WITH ALL THE DRAINS INOPERATIVE, IT SHOULD WITHSTAND 10” RAINFALL IN24 HOURS.
THE DECK SHOULD HAVE SUFFICIENT BUOYANCY WITHTWO ADJACENT PONTOONS PUNCTURED.
DURING INITIAL FLOATING OF THE ROOF, ALL THE PONTOONS ARE VISUALLY INSPECTED FOR ANY LEAKS OR SWEATING.
TANK ROOF
ROOF APPURTENANCES AND FEATURES
•ROOF MANWAYS•INSPECTION HATCH•RIM VENT WITH RELIEF VALVE•AUTO BLEEDER VENT•EMERGENCY DRAIN•GAUGE WELL PIPE AND ANTI ROTATION DEVICE•ROOF DRAIN•FOAM DAM•ROLLING LADDER
TANK ROOF
FLOATING ROOF - EITHER SINGLE DECK OR DOUBLE DECK
TOP DECK
BOTTOM DECK
ROOF DRAIN
SUPPORTINGLEGS
SEAL AREA
TANK BOTTOM
FLOATING ROOF - EITHER SINGLE DECK OR DOUBLE DECK
TOP DECK
BOTTOM DECK
ROOF DRAIN
SUPPORTINGLEGS
SEAL AREA
Sampling
• Important aid to Quality control• For ascertaining the stock conformity to
the relevant specifications• Sampling aids like sample grabber,
sample thief, water finding paste, sample containers
• Sealing of the sample container with proper seal. Sealing Wax not permitted.
Type of the Samples
• Top sample• Upper Sample• Middle Sample• Lower Sample• Bottom Sample• All Level Sample• Composite Sample• Water Draw off Line Sample
Bhakti
Samples
Sample: A portion extracted from a total volume that may or may not contain the constituents in the same proportion that are present in the total volume.
SPOT SAMPLE: A sample taken at a specific location or at specific time from a flowing stream
TOP SAMPLE: A sample obtained 15 cm below the top surface of the liquid
UPPER SAMPLE: A sample drawn from the middle of the upper one third of the tank contents (or one sixth of the total tank contents)
Samples
MIDDLE SAMPLE BOTTOM SAMPLELOWER SAMPLE: A sample drawn from the middle
of the lower one third of the tank contents (or five sixth of the total depth of the liquid.
COMPOSITE SAMPLE: A blend of U M and L Samples
ALL LEVEL SAMPLES: A sample obtained by submerging a stoppered beaker or bottle to a point as near as possible to the draw off point and raising it at a rate such that it is 75 % - 80 % full as it emerges out of the liquid.
Samples
COMPOSITE SAMPLE: The composite sample shall be a mixture of an equal quantity of :
U, M and L samples for product depth above 4 Meters
U and L samples for product depth between 2M to 4 M
Middle sample for product depth below 2 meters.
Sampling Procedure – (p- ½)
• The sampling bottle and sample containers shall always be kept clean.
• Before use, they shall be rinsed with the product under sampling.
• Only the type of sample required for the relevant specification to be tested, shall be taken.
• The sample quantity collected shall be sufficient for carrying out the relevant tests.
Sampling Procedure- (p 2/2)
• Sample shall be taken preferably during the cooler part of the day and under shade.
• The sample container shall be properly closed and it shall be ensured that there are no leaks.
• Sample details shall be entered in the form (as per Appendix-11/Appendix 11A) as applicable and fixed to the container.
• Sampling and filling of the sample container shall be personally supervised by an officer well conversant with the procedures.
Weathering of Volatile Samples
• Density
• RVP, RON
• Distillation– IBP– Recovery % Vol at 70, 100, 180 deg C
Sampling
• Avoid vapor loss of samples due to evaporation, particularly the retention samples
– Direct exposure to sun-light/heat
– Air Current
Gauging Procedures- (p 1/3)
The Gauging operations include:
• Measuring volumetric quantity of the tank by dipping or ullaging
• Recording the temperature of the product
• Measuring the density of the product
Gauging Procedures- (p 2/3)
Method for recording gross and water dips:Apply water finding paste to the bob, 2 cms above
the previous water dips.Apply oil finding paste around the range of
estimated Gross Dip.Lower the bob through the Gauge Hatch, till the
reading is 30 cms short of the reference height. Weight for the ripples to subside and then slowly lower the bob until it just touches the datum plate.
Raise the Tape and note the Gross Dip and the water dip.
Gauging Procedures- (p 3/3)
In tanks, where water dip is maintained, it should be at least 2 cm above the Datum Plate.
In case of tanks where water level is below the Datum Plate, the same shall be checked through the Centre Hatch.
For tanks which are to be kept bone dry, the same shall be assured by draining product through water draw off lines.
Layering in storage Tanks
• Heavier product in lighter product
• Interface Heavier at the bottom
• Circulation of product – Jet Mixtures
Master Instruments
• Master instruments : Hydrometers, Thermometers
• Validity : 5 Years• In-use instruments :
Yearly comparison and records.
Calibration
• Calibration of Hydrometers and Thermometers: Calibration to carried out at 3 – 4 points in the instrument’s range
• If the error is within +/- 0.0005 at 15 deg C
• If the error is within +/- 0.5 deg C
PRODUCT LOSS CONTROL
• Petroleum Products being volatile, product loss is unavoidable under certain circumstances. But these losses can be minimised.
• The losses erode profit.
• They cause safety hazards and pollute the environment.
PRODUCT LOSS CONTROL
• Identify the cause and initiate steps to eliminate it.
• Regular Inspections and Preventive Maintenance
• Awareness of employees.
Factors contributing to Pipeline Losses
• Defective Gauging Equipment/ Gauging errors/ Accounting errors
• Sludge/ Water in the tanks
• Gauging Errors
• Migration of Product
• Pilferage/ Leakage in the Pipeline
Control on Pipeline Losses
At the Pumping end:
• The tanks should be free from water/ sludge
• Proper settling time (Minimum 24 Hrs) to be given to the tank
• Positive segregation from other tanks
• Pumping of hot product to be avoided
• Use of standard Gauging Equipment. The same equipment to be used for Opening and closing operations.
Control on Pipeline Losses
At the Receiving end:
• The tanks should be free from water/ sludge
• Water dips to be noted before and after the receipts (Care to be taken for rain water)
• Positive segregation from other tanks
• Use of standard Gauging Equipment. The same equipment to be used for Opening and closing operations.
OIL ACCOUNTING
• CALCULATIONS ACCORDING TO ASTM, ARE BASED ON THE PROCEDURE WHERE A VOLUME MEASURED AT A GIVEN TEMPERATURE IS RECALCULATED TO A VOLUME AT THE STANDARD TEMPERATURE USING VOLUMETRIC CORRECTION. THIS CORRECTED VALUE IS CALLED STANDARD VOLUME. THE MASS OF THE PRODUCT IS OBTAINED BY MULTIPLYING THE STANDARD VOLUME BY THE PRODUCT’S DENSITY AT STANDARD TEMPERATURE.
ASTM TABLES
THE CORRECTION FACTORS ARE AVAILABLE IN THE FOLLOWING ASTM TABLES:
• TABLE 53 A : CORRECTION OF OBSERVED DENSITIES TO DENSITY AT 15 DEG c OF CRUDE OILS
• TABLE 53 B : CORRECTION OF OBSERVED DENSITIES TO DENSITY AT 15 DEG c OF PRODUCTS
• TABLE 54 A : CORRECTION OF VOLUMES TO 15 DEG C AGAINST DENSITY AT 15 DEG c FOR CRUDES
• TABLE 54 B : CORRECTION OF VOLUMES TO 15 DEG C AGAINST DENSITY AT 15 DEG c FOR PRODUCTS
ASTM TABLES
TABLE 53 B:
GIVES THE VALUE OF DENSITY IN KG/CU.M AT 15 DEG C CORRESPONDING TO A HYDROMETER READING AT OBSERVED TEMPERATURES OTHER THAN 15 DEG C.
TWO CORRECTIONS ARE NECESSARY AND HAVE BEEN APPLIED:
THE CHANGE IN VOLUME OF GLASSS HYDROMETER WITH TEMPERATURE (STEM CORRECTION)
CHANGE IN THE VOLUME OF PRODUCTS WITH TEMPERATURE
ASTM TABLES
TABLE 54 B:
GIVES THE VOLUME CORRECTION FACTORS FOR CONVERTING PRODUCT VOLUMES OBSERVED AT TEMPERATURES OTHER THAN 15 DEG C TO CORRESPONDING VOLUMES AT 15 DEG C.
ASTM TABLES
If the Hydrometer Reading for a Gasoline at 22 deg C is 733 kg/m. cu, what is the density of gasoline corrected to 15 deg C.
738.7 KG/M CU
ASTM TABLES
If the Hydrometer Reading for An HSD at 30 deg C is 836 kg/m. cu, what is the density of HSD corrected to 15 deg C.
846.0 KG/M CU
ASTM TABLES
What is the volume at 15 deg C of 55000 cu M at 30 deg C of heating oil the density of which at 15 deg c is 845.7 kg/m cu.
54336.7 m cu.
Out turnsFOR CONE ROOF TANKS:1. From the Dip Memo, calculate the Gross Dip
Quantity and water Dip quantity2. Compute Net Oil at Observed Temperature3. Compute 15 deg C Density from the observed
sample Temperature and the hydrometer Reading4. Compute VRF against Observed Tank
Temperature5. Compute WRF (subtract 0.0011 from Density at
15 deg C)6. Calculate volume at 15 deg C by: V (obs
temp)xVRF7. Calculate MT by : V at 15 deg C x WRF
Out turnsFOR FLOATING ROOF TANKS:
1. All the steps as in cone roof are involved with one extra step i.e. Roof correction.
2. Volume displaced by the Roof = Weight of roof / Density of the product
3. The displaced volume is subtracted from Gross oil to get the Net oil at Observed temperature.
Out turnsPrepare an OTR for the following data:
Tank No. 3
Type : Cone Roof
Product : HSD
Parameters Opening Closing
Gross Dip 61.1 cm 415.7 cm
Water Dip (c) 0.0 cm 0.0 cm
Tank Temp. 18.0 deg C 21.5 deg C
Sample Temp. 18.0 deg C 21.0 deg C
Observed density 0.829 0.831
Out turnsPrepare an OTR for the following data:
Tank No. 11
Type : Floating Roof
Product : MS
Parameters Opening Closing
Gross Dip 295.5 cm 1396.5cm
Water Dip (c) NIL Nil
Tank Temp. 17.0 deg C 16.5 deg C
Sample Temp. 16.0 deg C 15.0 deg C
Observed density 0.745 0.740
OIL RECONCILIATION• A COMPARISON OF OPENING AND
CLOSING BALANCES• OPENING BALANCE CONSISTS OF • QUANTITY PUMPED• QUANTITY UNDER PUMPING• OPENING LINEFILL• CLOSING BALANCE CONSISTS OF• QUANTITY DELIVERED• QUANTITY UNDER DELIVERY• CLOSING LINEFILL• ALL QUANTITIES ARE VOLUMES AT 15
DEG C
Form No. OP 28
INDIAN OIL CORPORATION LTD.(MARKETING DIV.)
OUT TERN FOR RECEIPT OT NO. 3133LOCATION : DELHIDATE : 21.01.2004
TANK NO. IOC 3 BONDED PRODUCT : HSD
BEFORE RECEIPT AFTER RECEIPT
DATE 14.01.2004 17.01.2004
TIME 14.15 HRS. 10.00 HRS.
TANK TEMP. IN DEG.C 18.0 21.5
SAMPLE TEMP. IN DEG. C 18.0 21.0
SAMPLE DENSITY 0.829 0.831
DENSITY AT 15 DEG.C 0.8310 0.8350
OIL & WATER HEIGHT/LTS 61.1 cm. / 628723 Ltrs.
415.7 cm. /3483008 Ltrs.
WATER HEIGHT/LTS. 0.0 cm. /0.0 Ltrs.
0.0 cm. /0.0 Ltrs.
VOLUME REDUCTION 0.9975 0.9946
NET OIL LTRS. AT (N)NET OIL LTRS. AT 15 DEG.CNET OIL QTY. IN MT
628723627150520.470
348300834642002888.796
NET QTY. RECEIVED
AT NATURAL AT 15 DEG. C MTS.
2854.285 KLS 2837.05 KLS 2368.326 MTS
BATCH NO = HSD HSD-309UL CENTRAL EXCISE
SUMMARY BONDED RECEIPT FROM PIPELINE EX-MATHURA FOR INDIAN OIL CORPORATION LTD. PIPELINE MARKETING
DETAILS OF CALCULATIONS VOL. IN KLS AT 61.1 cms = 628723 8 415.7 cms = 34830086VOL CORR. UPTO DATUM = 0 = 0 GROSS QTY. IN LTRS. : 628723 3483008 ROOF CORR. IN LTRS. : 0 0WATER QTY. IN LTRS. : 0 0 CERTIFIED THAT THE PARTICULARS GIVEN ARE CORRECT PLACE ______NEW DELHI _______DATE __________PLANT TERMINAL MANAGER REGD. OFFICE : G-9 ALI YAWAR JUNG MARG, BANDRA(EAST) BOMBAY – 400 051(INDIA)
Form No. OP 28
INDIAN OIL CORPORATION LTD.(MARKETING DIV.)
OUT TERN FOR RECEIPT OT NO. 4547LOCATION : DELHIDATE : 23.01.2004
TANK NO. IOC 11 BONDED PRODUCT : MS
BEFORE RECEIPT AFTER RECEIPT
DATE 17.01.2004 21.01.20042
TIME 10.15 HRS. 07.30 HRS.
TANK TEMP. IN DEG.C 17.0 16.5
SAMPLE TEMP. IN DEG. C 16.0 15.0
SAMPLE DENSITY 0.745 0.740
DENSITY AT 15 DEG.C 0.7458 0.7400
OIL & WATER HEIGHT/LTS 295.5 cm. / 1407233 Ltrs.
1396.5 cm. /6378777 Ltrs.
WATER HEIGHT/LTS. 0.0 cm. /0.0 Ltrs.
0.0 cm. /0.0 Ltrs.
VOLUME REDUCTION 0.9978 0.9983
NET OIL LTRS. AT (N)NET OIL LTRS. AT 15 DEG.CNET OIL QTY. IN MT
135225013492751004.805
632342363126734664.434
NET QTY. RECEIVED
AT NATURAL AT 15 DEG. C MTS.
4971.173 KLS
4963398KLS
3659.629MTS
BATCH NO = MS MS-311PG CENTRAL EXCISE
SUMMARY BONDED RECEIPT FROM PIPELINE EX-MATHURA FOR INDIAN OIL CORPORATION LTD. PIPELINE MARKETING
DETAILS OF CALCULATIONS VOL. IN KLS AT 295.0 cms =1404974 1395 cms = 6372021
0.5 cms = 2259 1.5 cms = 6756VOL CORR. UPTO DATUM = 0 = 0 GROSS QTY. IN LTRS. : 1407232 6378777ROOF CORR. IN LTRS. : 54982 55354WATER QTY. IN LTRS. : 0 0 CERTIFIED THAT THE PARTICULARS GIVEN ARE CORRECT PLACE ______NEW DELHI _______DATE __________PLANT TERMINAL MANAGER REGD. OFFICE : G-9 ALI YAWAR JUNG MARG, BANDRA(EAST) BOMBAY – 400 051(INDIA)
THANK YOU
