IS-10987 for tanks or petrolium products

8/12/2019 IS-10987 for tanks or petrolium products

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IS 10987 : 1992

CODE OFFABRICATION,

Tm F*qQT)Indian Standard

PRACTICE FOR DESIGN,TESTING AND INSTALLATIONOF UNDER-GROUND/ABOVE-GROUNDHORIZONTAL CYLINDRICAL STEEL STORAGETANKS FOR PETROLEUM PRODUCTSFirst Revision )

UDC 621.642.37/*39-005 : 665*6/-7 : 006.76

@ BIS 1992BURE U OF INDI N ST ND RDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002March 1992 Price Group 5

( Reaffirmed 1998 )


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Structural Engineering Sectional Committee, CED 7

FOREWORDThis Indian Standardthe draft finalized bv ( Pirst Revision ) was adopted by the Bureau of Indian Standards, afterthe Structural Engineering Sectional Committee had been approved by theCivil Engineering Division Council.This code has been prepared to provide the petroleum industry with tanks of adequate safetyand reasonable economy which can be built in any size required to meet the needs of the indus-try subject to the limitations given in this code and to establish uniformity in designing,fabricating, testing and installing the horizontal storage tanks.This code is not intended to establish a fixed series of allowable tank sizes but to assist thepurchaser in the selection of the size of the tank that may be required to meet his particularneed.Ihis code was first published in 1984. In the first revision, based on the experience gained in theuse of this code, following major modifications have been effected:

a) Minimum shell plate thickness both for underground and above-ground tanks has beenmodified as 5.00 mm for tanks up to 20 kiIolitre capacity.b) A clause reIating to earthing connection to safeguard the tanks from the accumulation ofstatic charge has been included.

In this code numerical values are given in SI units only.In the preparation of this standard assistance has been derived from BS 2594 : 1975


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IS 10987 : 1992

Indian StandardCODE OF PRACTICE FOR DESIGN,FABRICATION,TESTINGAND INSTALLATIONOFUNDER-GROUND/ABOVE-GROUNDHORIZONTALCYLTNDRICALSTEELSTORAGETANKSFORPETROLEUMPRODUCTS

irst Revision )1 SCOPE1.1 This code is intended to provide purchasersand manufacturers with guidelines in design,fabrication, testing and installation of under-ground as well as above-ground horizontalcylindrical steel tanks with flat ends for storageof petroleum products.1 1 1rovisions of this code may aIso be appliedto design and construct tanks for storage ofvarious chemicals having specific gravity Iessthan one. In such cases, special considerationsregarding lining and corrosion allowance shallbe made while designing the tanks for intendeduse.1.1.2 Provisions of this code are applicable forstorage of products under ambient temperatureand atmospheric pressure conditions.1.2 This standard is complementary to IS 800 :1984 and IS 816 : 1969.1.2.1 Provisions regarding permissible stresses,design, fabrication and erection as included inIS 800 : 1984 shall apply unless specified other-wise in this code.1.2.2 For provisions regarding analysis forsaddle support and associated local loads,reference shall be made to IS 2825 : 1969.1.3 The above-ground storage tanks covered inthis standard are not intended for mobileapplication.1.4 Unless otherwise stated specifically, provi-sions, covered in this standard apply to bothabove-ground and underground tanks.2 REFERENCESThe Indian Standards listed in Annex A arenecessary adjuncts to this standard.

3 STATUTORY PROVISIONSCompliance with this code does not absolveanyone from the responsibility of observingany statutory provisions as may have beenpromulgated by the statutory bodies, such asDepartment of Explosives, Nagpur.4 DEFINITION AND SYMBOLS4.1 Underground TankA tank placed in earth, masonry or concretepit and packed around with sand, earth or clayleaving no air space between the tank and thepit. No part of the tank is visible.4.2 Welding Terms and Symbols4.2.1 Weldi ng TermsShall be according to IS 812 : 1957.4.2.2 Symbol s for Wel ding Used on Pl ans andDrawingsShall be in accordance with IS 813 : 1986.5 NOTATIONSFor the purpose of this standard, the followingnotations shall have the meaning indicatedagainst each ( see Fig. 1 ).

B=B, =c=D=E=

Steel saddle widthWidth of wear plate of saddle support(B,>B+ lot,)Steel saddle breadthShell outside diameterSpacing between saddle supports

H = Height of the stiffenerL = Overall lengthb = Width of saddle support

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IS 10987 : 1992

L:EG DIP/ MANHOLE /CONNECTIONr&

STIFFENERS LINE

_.~-t- xnmm 6Omin.

PIG;. 1 TYPICALARRANGEMENT F ABOVE-GROUNDHORIZONTALTANKt,,, = End plate thicknesst, = Shell plate thickness, M i nt, = Wear plate thickness

6 GENERAL6.1 The tank may $e manufactured from suit-able size plates covered in IS 1730 : 1989.6.2 Table I covers recommended sizes, platethickness for tanks of various nominal capaci-ties up to 90 kl. The shell and end plate thick-nesses include a corrosion allowance of l-5 mm.6.3 General arrangements for above-groundand underground tanks are shown in Fig. 1and 2, respectively.6.4 Enquiries or Order FormWith a view to facilitating the manufacturingand supply of welded oil storage tanks, certaindetailed information is to be supplied to themanufacturer. The information so required islisted in Annex B.7 MATERIALS7.0 GeneralUnless agreed otherwise, the material for theconstruction of oil storage tanks shall conformto Indian Standards, where applicable.7.1 Structural Steels7.1.1 Steel plates and sections used in thetank construction shall conform to any one ofthe following specifications:IS 226 : 1975, IS 961 : 1975, IS 2002 : 1982,IS 2041: 1982, 1S 2062 : 1984 or IS8500: 1977.

NOTE - The plate material specified in 7.1.1 maybe used without impact testing for tank shells and&s r;FFrcements for design metal temperature up- O.7.1.2 The dimension of structural steel sectionsand plates used in tank construction shallconform to IS 808 : 1989 and IS 1730 : 1989,respectively.7.2 Cast Steel MountingsThe mountings shall be suitable for welding andshall conform to Grade 3 of IS 1030 : 1982.7.3 ElectrodesThe electrodes for meta arc welding shall con-form to IS 814 : 1991.7.4 PipingUnless specified otherwise the pipe and pipecouplings shall conform to IS 1978 : 1982. If sospecified in the contract or order, couplings forthreaded connections may be supplied withoutrecesses; when so supplied the coupling in allother respects shall conform to IS 1978 : 1982.Pipes used for structural purposes shall conformto IS 1978 : 1982 or IS 1979 : 1985 with respectto physical properties of the material. Pipes ofheavy class conforming to IS 1239 ( Part 1 ) :1990 may be used for nozzles on tank andinternal piping, if so specified in the contractor order.7.5 FlangesPlate ring flanges shall be made from any of theplate material listed in 7.1.1. Requirements ofslip on welding and welding neck flanges arecovered in IS 6392 : 1971.

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IS 10987 1992

RAW-OFF.PO IN1

V NTCONNECT ION

FIG. 2 TYPICAI,ARRANGEMENT F UNDER-GROUNDHORIZONTALTANK7.6 Bolts and Nutsolts shall conform to property class 4.6 or4.8 and other requirements specified in IS 1367( Part 3 ) : 1979. Nuts shall conform to pro-perty class 4 of IS 1367 ( Part 6) : 1980.

7.7 Other materials used in association withsteel work shall, where appropriate IndianStandard specifications for materials exist,conform to such specifications.8 PERMISSIBLE STRESSES8.1 Maximum permissible stresses in shell andother structural members shall not exceedvalues stipulated in 8.1.1, 8.1.2 and 8.1.3.8.1.1 In the design of tank shells, the maximumpermissible tensile stress before applying thefactor of joint efficiency of O-7 shall not exceed165 MPa in case of steels conforming toIS 226 : 1975 and IS 2062 : 1984. For other steelsthis shall be taken as 0.70 of the minimumyield stress or O-4 of the minimum tensile stressspecified, whichever is less.8.1.2 The permissible stresses in compression,buckling, shear, bearing, etc ( not coveredin 8.1.1 ), shall not exceed those specified inIS 800 : 1984. For this purpose steel conformingto IS 2002 : 1982 and IS 2041 : 1982 shall betreated as equivalent to IS 226 : 1975 or IS2062 : 1984 whereas Type 2 steel conformingto IS 2041 : 1982 shall be treated as equivalentto IS 961 : 1975.8.1.3 The stresses specified in 8.1.1 and 8.1.2are applicable for design temperatures of - 10Cto + 200C.8.2 The permissible stresses for welds andwelded connections shall conform to the valuesgiven IS 816 : 1969.

9 DESIGN9.1 Tanks manufactured to provisions of thiscode, shall be designed for a pressure of 0.05MPa when full of water. Thicknesses chosenshall not be less than the thicknesses given inTable 1.9.2 Tanks to be installed underground shallalso be designed for external earth pressureacting on the tank when it is empty.9.3 Corrosion AllowanceMinimum corrosion allowance of l-5 mm shallbe considerd in design of tanks. To safeguardagainst corrosion caused by the environmentand the product stored 1.1.1 and 10 should befollowed.9.4 Design TemperatureThe design temperature shall be the lowest oneday mean temperature where the tank is to beinstalled, as available from relevant IS codes,metreological department or local authorities.9.5 Poundation9.5.1 Tanks shall be built on good foundations.Above-ground tanks shall be provided withsteel wear plates for installing them on con-crete pedestals or steel cradles as specified bythe purchaser.9.5.2 Typical arrangement for above-groundtank is given in Fig. 1. Concrete pedestals shallbe designed to support the tank full with water.9.5.3 As tank diameter or shell thickness ratioincreases, the shell shall be analysed for buck-ling resistance to reaction loads at the concretepedestals _and associated local loads as perIS 2825 : 1969.

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IS 10987 : 1992Table 1 Dimensions and Capacities of Horizontal Underground and Above-Ground StorageTanks With Flat Ends

( C/auses 6.2, 9.1, 13.4 and 14.3)Nominal ShellCapacity O -

Dia-

1Kl57.5

1015202530354045505560IO8090

Overall SpacingLength BetweenSaddlesupportsmeter

D L E(2) (3) (4)mm mm mm

1 600 2 750 2 1101 600 4 000 3 6101 800 4 250 3 5301 950 5 503 4 1202 250 5 500 46002 500 5500 4 5002 650 6 003 4 9102 700 6 750 5 6702 750 7500 6 4002 750 8 250 7 1002 750 9000 7 9002 750 10 000 8 9002 750 11000 99002 750 13 000 119002 750 14 750 13 6502 750 16 500 15 400

Thickness Size of Minimum Minimum Approximate_-----_-_-.---~ Stiffners Width Breadth WageWear Shell Plate End Plate ( angle of AboveNominallate h withGnz- Above; Stiffners Secti&s) SaddleSupport Capacityground groundtank tank BSaodfde

SupEorttw ts

(5) 6)mm mm6-O 5.06-O 5.06.0 5.06.0 5.08.0 6.08.0 6.08.0 6.08.0 6.08.0 6.08-O 6.08.0 6.08.0 6.08.0 6.08.0 608.0 6.080 6.0

L7)mm mm

5.0 6.05.0 6.05.0 8.05.0 8.05.0 8.06.0 10.08.0 10.08.0 10.08.0 10.08.0 10.08.0 10.08.0 10.08.0 10.080 10.0

10.0 10.010.0 10.0

9) 10)mm mm65x65~6 15065x65~6 15065x65~8 25070X70X8 25090X90X8 25090X90X 10 250

100x100x10 250100x 100x 10 250100x100x10 250lCOxlOOxlO 250100x 100x 10 250100x100x10 550100x 100x 10 250100x 100x 10 250100x100x10 250100x100x10 250

(11)mm1 3851 3851 5601 6901 9502 2952 3402 3302 3802 3802 3802 3802 3802 3802 3802 380

(12)percent7.84.95.97.57.56.38.3s-49.57.25.26.47.38.77.77.1

NOTES1 The thickness specified above are the minimum requirement only (including internal and external corrosionallowance ), pertaining to yield value of steel as 250 MPa.2 The actual thickness required shall be checked taking into the consideration soil pressure, fluid pressureand external loading.3 End plates in co1 8 of the flat ends shall be provided with stiffners given in co1 9 and agreed as per Fig. 3E.4 End plates of the flat ends shall preferably be without joints.two or more plates, the weld joint shall be made horizontal. Where the end plate is made by welding ofthe bottom. Full width of plate( s ) should be utilized at

10 CORROSION PROTECTIONTanks to be installed underground shall besuitably protected against corrosion caused bythe soil strata and/or sub-soiI water. Thepurchaser shall specify type of such protectionthat he considers desirable. Suggested goodpractices for asphalt doping are given inAnnex C.11 TANK ANCHORAGE11.1 Tank to be installed underground shall beanchored to resist the buoyancy force inducedby high water tables that may occur seasonally.The anchorage could be either provided bymeans of steel flat of round bars having ade-quate cross section to resist the uplift at astress level of 140 MPa maximum.

11.2 The anchors should be embedded in RCCdraft having necessary dead weight, bondingand shear strength to resist the uplift force.12 APPURTENANCES AND MOUNTINGS12.1 General12.1.1 Appurtenances or mountings installedon tanks shall conform to this code. Alternativedesigns of appurtenances which provide equiva-lent strength, tightness and utility are permis-sible, if so agreed to by the purchaser.12.1.2 Manhole necks, nozzle necks, reinforcingplates and shell-plate openings which haveeither sheared or oxygen-cut surfaces, shallhave such surface made uniform and smooth,with the corners rounded, except where suchsurfaces are fully covered by attachment welds.

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IS 10987 : 199212.1.3 The opening in tank larger than 65 mm 12.53 Vent Connectionin diameter shall be reinforced. The minimumthickness of the reinforcing pad shall be the The vent pipe shall be securely supported andsame as the shell thickness and diameter shall shall not be less than 4 m in height and at 4 mbe twice the diameter of the hole cut subject distance from any adjoining land or propertyto maximum diameter of the opening plus or any other source of fire. Vent pipe of any200 mm. tank shall not be interconnected with that ofanother. The open end of every vent pipe shall12.2 Manhole be covered with two layers of non-corrodiblemetal wire gauge having not less than 11 meshes12.2.1 Each tank shall have a minimum of one per linear centimetre and shall be furthermanhole of not less than 500 mm size protected from rain by a hood or by suitably( diameter ). bending it downward.12.2.2 The manhole cover may be hinged with 12.5.4 Earthing Connectionsingle or multiple bolt fixing, as required by thepurchaser. The horizontal storage tank, whether above-

ground or underground, shall invariably be12.3 Nozzles provided with earthing connection to elimi-nate the possibility of accumulation of staticThe nozzle sizes shall be selected to meet charge on the surface of the tank either due toindividual operating conditions of filling and atmospheric electricity or due to flow of productemptying rates. into the tank.For this purpose, two earthing bosses of appro-12.4 Lifting Lugs priate sizes shall be welded to the saddlesupport in case of above-ground tanks and toThe lifting lugs shall be provided in the tankat appropriate position to lift the empty tanks the end plate in case of underground tanks.Guidelines for making earthing connection foronly. Typical details of lugs and positions are tanks are also given in Annex D.shown in Fig. 1 to 3.12.5 Accessories 13 FABRICATION AND SHOP PAINTINGThe tank shall be provided with a fill connec- 13.1 The workmanship and finish shall be firsttion, a draw-off connection, a dip-connection class in every respect subject to closest inspec-a vent connection and a drain connection. tion by the manufacturers inspector, whetheror not the purchaser, waives any part of the12.5.1 Fi l l Connection inspection.13.1.1 The tanks shall be fabricated by welding.When the tank is filled from the top, an internal Welding procedure in general and the qualifi-fill pipe running down to within 100 mm of the cation of welders shall be as specified intank bottom shall be provided to avoid splash- IS 9595 : 1980and IS 817 : 1966.ing of product and generation of staticelectricity. End of the fill pipe shall be 13.2 The cylindrical shell shall be of fullchamfered at 45. penetration double butt-welded construction.12.5.2 Dip ConnectionThe dip connection shall be provided with agalvanized ircn, aluminium or brass screwedcover and be fitted with an internal perforatedpipe running down to within 100 mm of thetank bottom. Appropriate perforation shall beprovided for various products. Alternatively,in case of above-ground tank a float arrange-ment for continuous gauging of liquid levelinside the tank may be used.12.5.2.1 The calibrated dip rod shah be of non-sparking material ( 12 mm square brass rod isrecommended ).

13.2.1 The end plates and penetration shall beattached to the cylindrical shell by means ofdouble fillet welds.13.3 Shell Plate Arrangement13.3.1 When the shell length is produced frommore than one single plate the longitudinalseams shall break joint at intermediate circum-ferential seams. It is recommended that whenverpossible a longitudinal seam should be situatedin the upper third of a tank or on the topcentre line.13.4 The end plates shall be adequately stiflened.The recommended size of angle stiffeners as

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IS 10987 : 1992given in Table 1 shall be arranged as perFig. 3 C.13.5 Typical weld joint details are shown inFig. 3.13.6 Shop PaintingAll the external surfaces of the tank shall bethoroughly cleaned and freed from rust andscale and painted with one coat of an approvedprimer paint. All the interior surfaces of thetank shall be cleaned to remove all rust andforeign matters like grease, dirt, etc, beforedespatch.14 TOLERANCES14.1 Tolerance on Shell DiameterThe tolerance on diameter at any point on thelength of the tank shell shall be within f 0.35percent of the specified diameter ( MUX ) whencalculated from an external circumferentialmeasurement.14.2 Tolerance on CircularityThe tolerance on circularity at any point onthe length of the shell that is the differencebetween maximum and minimum internal shelldiameter, shall not exceed one percent of thenominal internal diameter.

4 f-+3rilmt al t,=Sbfimm 8mm OPTIONAL)

-+/ +3mmb) 15 = 8mm AND 10 mm

14.3 Tolerance on Overall LengthThe overall length of the tank shall not differby more than 0.5 percent of the overall lengthgiven in Table 1.15 INSPECTION AND TESTING15.1 Examination of welds shall be done byvisual means. However, non-destructive testingsuch as spot radiography may be carried out atthe option of the purchaser.15.2 All gauges and templates necessary forinspection, to the satisfaction of the inspectorshall be supplied by the manufacturer.15.3 All tanks shall be subjected to hydraulictest at a pressure of O-05 MPa and checked forleaks.16 CALIBRATION16.1 Tanks may be calibrated mathematicallyunless otherwise specified by the purchaser.Where physical calibrations are specified by thepurchaser, tanks shall be calibrated in accor-dance with IS 2009 : 1975 using a certifiedwater. Calibration tables shall show volume ofproduct for every 0.5 cm of filling height of thetank.16.2 Calibration may be certified by anindependent authority, if so required by thepurchaser.

NUOUS tT WELDSHELL

ia)

b)3A TYPICAL LONGITUDINAL AND CIRCUMFERENTIAL 3B TYPICAL SHELL TO COUPLING

JOINTS OF SHELL JOINT DETAILS

FIG. 3 TYPICAL WELD JOINT DETAILS - continued )6


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IS 10987 992

CONTINUOUSFILLET WELD

3C TYPICAL JOINT FOR MAN IHOIL

b)_E AND NOZZLE NECK TO SHELL

120mm

wONTlNUOUSFILLET WELD3D WELD JOINT FOR FLAT ENDS AND LIFTING LVG

PLANE

SECTION YY

3E STIFFENING DETAILS OF END PLATEPIG. 3 TYPICA d WELD JOINT DEII AlLS

SECTION XX


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IS 10987 992

S No226 : 1975800 : 1984

8 8 : 1989

812 : 1957

813 : 1986814.: 1991

816 : 1969

817 : 1966

961 : 19751030 : 1982

1239( Part 1) : 1990

1367( Part 3 ): 1979

ANNEX Alause2 )

LIST OF REFERRED INDIAN STANDARDS

Tit leStructural steel ( standard qua-lity ) (fifth revi si on )Code of practice for generalconstruction in steel ( secondrevi sion )Dimensions for hot rolled steelbeam, column channel andangle sections ( revised )Glossary of terms relating towelding and cutting of metalsScheme of symbols for weldingCovered electrodes for manualmetal arc welding of carbonand carbon manganese steel( _@ a evi sion )Code of practice for use ofmetal arc welding for generalconstruction in mild steel j rstrevi si on )Code of practice for trainingand testing of metal arc welders( revised )Structural steel ( high tensile )( second revi sion )Carbon steel castings forgeneral engineering purposes( second revision )Mild steel tubes, tubulars and

IS No.

1367(Part 6 ): 1980

1730 : 1989

1978 : 19821979 : 19852002 : 1982

2009 : 1975

2041 : 1982

2062 : 1984

2825 : 1969

6392 : 19711977other wrought steel fittings:Part 1 Mild steel tubes (fifth 8500 :revi si on )

Technical supply conditions forthreaded steel fastners: Part 3 9595:Mechanical properties and testmethods for bolts, screws and1980

Tit lestuds with full loadability( second revision )Technical supply conditionsfor threaded steel fastners:Part 6 Mechanical propertiesand test methods for nuts withspecified proof loads ( secondrevi si on )Dimensions for steel plate,sheet, strip and flats for generalengineering purposes ( secondrevi sion )Line pipe ( second revision )High test line pipe ( rstrevi si on )Steel plates for pressure vesselsfor intermediate and high tem-perature services includingboilers ( j i rst revi sion )Method for calibration ofhorizontal and tilted oil storagetanks ( first revision )Steel plates for pressure vesselsused at moderate and lowtemperature ( rst revi si on )Weldable structural steel ( th irdrevi sion )Code for unfired pressurevesselsSteel pipe flangesWeldable structural steel( medium and high strengthqualities )Recommendations for metalarc welding for carbon andcarbon manganese steels
http://../link/15to30/226.Bishttp://../link/61to88/800.Bishttp://../link/61to88/808.Bishttp://../link/61to88/812.Bishttp://../link/61to88/813.Bishttp://../link/61to88/814.Bishttp://../link/61to88/816.Bishttp://../link/61to88/817.Bishttp://../link/89to99/961.Bishttp://../link/10/1030.Bishttp://../link/10/1030.Bishttp://../link/12/1239_1.Bishttp://../link/13and14/1367_3.Bishttp://../link/13and14/1367_6.Bishttp://../link/15to30/1978.Bishttp://../link/15to30/1979.Bishttp://../link/15to30/2002.Bishttp://../link/15to30/2009.Bishttp://../link/15to30/2041.Bishttp://../link/15to30/2062.Bishttp://../link/15to30/2825.Bishttp://../link/61to88/6392.Bishttp://../link/61to88/8500.Bishttp://../link/89to99/9595.Bishttp://../link/89to99/9595.Bishttp://../link/61to88/8500.Bishttp://../link/61to88/6392.Bishttp://../link/15to30/2825.Bishttp://../link/15to30/2062.Bishttp://../link/15to30/2041.Bishttp://../link/15to30/2009.Bishttp://../link/13and14/1367_3.Bishttp://../link/12/1239_1.Bishttp://../link/10/1030.Bishttp://../link/89to99/961.Bishttp://../link/61to88/817.Bishttp://../link/61to88/816.Bishttp://../link/15to30/2002.Bishttp://../link/15to30/1979.Bishttp://../link/15to30/1978.Bishttp://../link/13and14/1367_6.Bishttp://../link/61to88/814.Bishttp://../link/61to88/813.Bishttp://../link/61to88/812.Bishttp://../link/61to88/808.Bishttp://../link/61to88/800.Bishttp://../link/15to30/226.Bis


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IS 10987 : 1992

INFORMATION

ANNEX ,J _( Chae 6.4 ) j

TO BE FURNISHED BY THE PURCHASER

B l The following information shall be suppliedby the purchaser in his enquiry: h) Corrosion allowance for shell. end nlates

a>b)c>4e)f 1g)

Location of tank;Nominal capacity of tank;Tank diameter and/or length restrictions;InternaI tank pressure and/or vacuum;Rate of filling and emptying tank;Product to be stored and its design andspecific gravity;Minimum ambient temperature wheretank is located or design metal tempera-ture;

and other parts both - internal- andexternal;j) Maximum wind speeds;k) Earthquake factor;m) Any additional loads to be consideredfor tank design;n) Type of foundation and bearing capacityof the soil;p) List of mountings required and theirlocation on the tank;q) Type of construction, lap or butt-welded;r) Extent of painting required and surfacepreparation; ands) Scope of supply of tank manufactured.

ANNEX C(Clause 10.1 )

ASPHALT DOPINGC l ASPHALT DOPINGAsphalt doping should be adopted to providesatisfactory protection to steeI against soilattack.

b)

C l.2 Doping of tank should not be taken inhand until the tank is finally tested inside thepit and all water emptied out. However, on theportion of the outside surface of tank whichcome in contact with cement concrete orfoundation, doping can be carried out ( as perthe laid down procedure/specifications ) beforetesting, excluding the welding joints portionswhich shall be completed after testing.C-l.3 Recommended practices for carrying outasphalt doping are as follows:

a) Surface Preparation-The outside surfaceof the tank, turn buckle, anchor bolts,burried portion of manholes, nozzles,saddles, etc, should be thoroughlycleaned by scraping with wire brushesand sand papers to bare metal. All millscales dirt should be completely removedbefore starting the doping work.

c)

9

Primer Coat - The surface thus preparedshould be treated with two coats ofTankmastic or equivalent primer. Eachcoat is applied uniformly after theprevious is completely dried. The approxi-mate coating capacity of Tankmasticor equivalent is about 11 to 13 mZ/lcoat.Doping - After the application of primercoats, two coats of hot 30140 Gradebitumen shall be applied as per manufac-turers recommendations, resulting in anoveraIl coating thickness of 3.2 mm.The 30/40 Grade bitumen shall be heatedto the required temperature as recom-mended by the manufacturer for easyand uniform appbcation of bitumen.The application of bitumen shaII be donein such a way as to give the appearanceof a rough cast plaster and this can beobtained by dabbing onIy and notpainting.


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IS 10987 : 1992

ANNEX DClause12.5.4 )

EARTHING CONNECTIOND-l GUIDELINES FOR MAKINGEARTHING connections and contacts shall have as fewCONNECTIONS joints as possible. All joints shall be riveted,welded or bolted and also soldered to ensureD-l.1 Every tank shall be electricalIy connected both mechanical and electrical soundness. Thewith the earth in an efficient manner by not less resistance to earth shall not exceed 70 and thethan 2 separate and distinct connections pIaced resistance to earth plate or to any part ofat the opposite extremities of such tank. The fitting shall not exceed 20.

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Standard MarkThe use of the Standard Mark is governed by the provisions of the ureau qf Indian

Standards Act 1986 and the Rules and Regulations made thereunder. The Standard Markon products covered by an Indian Standard conveys the assurance that they have beenproduced to comply with the requirements of that standard under a well defined systemof inspection, testing and quality control which is devised and supervised by BIS andoperated by the producer. Standard marked products are also continuously checked byBIS for conformity to that standard as a further safeguard. Details of conditions underwhich a licence for the use of the Standard Mark may be granted to manufacturers orproducers may be obtained from the Bureau of Indian Standards.


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BIS is a statutor institution established under the Bureau of Indian Standards AC? 1986 toof the activities of standardization, marking and qualitycertification of goods and attending to connected matters in the country.CopyrightBIS has the copyright of all its publications. No part of these publications may be reproducedin any form without the prior permission in writing of BIS. This does not preclude the free use,in the course of implementing the standard, of necessary details, such as symbols and sizes, typeor grade designations. Enquiries relating to copyright be addressed to the Director( Publications ), BIS.Revision of Indian StandardsIndian Standards are reviewed periodically and revised, when necessary and amendments, ifany, are issued from time to time. Users of Indian Standards should ascertain that they are inpossession of the latest amendments or edition. Comments on this Indian Standard may besent to BIS giving the following reference:Dot : No. CED -l 4728 )

Amendments Issued Since PoblicationAmend No. Date of Issue Text Affected

BUREAU OF INDIAN STANDARDSHeadquarters :Manak Bhavao, 9 Bahadur Shah Zafar Marg, New Delhi 110002Telephones ; 331 01 31, 331 13 75 Telegrams t Manaksanstha

( Common to all Offices )Regional Offices ICentral : Manak Bhavan, 9 Bahadur Shah Zafar MargNEW DELHI 110002Eastern : l/14 C. I. T. Scheme VII M, V. I. P. Road, MaoiktolaCALCUTTA 700054

TelephoneI 331 01 31331 13 75

37 86 62Northern ; SC0 445-446, Sector 35-C, CHANDIGARH 160036 53 38 43Southern : C. I. T. Campus, IV Cross Road, MADRAS 600113 235 02 16Western : Maoakalaya, E9 MIDC, Marol, Andheri ( East ) 6 32 92 95BOMBAY 400093Branches : AHMADABAD, BANGALORE, BHOPAL, BHUBANESHWAR, COIMBATORE,FARIDABAD, GHAZIABAD, GUWAHATI, HYDERABAD, JAIPUR, KANPUR,LUCKNOW, PATNA, THIRUVANANTHAPURAM.

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Documents

IS-10987 for tanks or petrolium products