NFPA 30-2008: Basic Requirements For Storage Tanks PDF

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NFPA 30-2008:Basic Requirementsfor Storage TanksNew York City Metro ChapterSociety of Fire Protection EngineersNew York, NY — February 22, 2011

NFPA 30, Flammable andCombustible Liquids CodeStorage TanksNew York City Metro ChapterSociety of Fire protection EngineersFebruary 22, 2011The Basics What is a flammable liquid?Fundamental hazardous property offlflammablebl andd combustibleb tibl liquidsli idis: their ability to produce ignitiblevaporsProperties vapor pressure & boiling pointflash point temperature at which vapors aboveliquid'sliquids surface can be ignitedfire point temperature at which liquid will ignite& sustain fire1

Properties autoignition temperaturevapor-air densityliquid densitywater miscibility water miscible liquids are afire fighting ationRateFlashPointClassificationClassFlash PointBoiling PointIA 73 F (22.8 C) 100 F (37.8 C)IB 73 F (22.8 C) 100 F (37.8 C)IC 73 F – 100 F( 22.8 - 37.8 C) 100 F - 140 F( 60 - 37.8 C) )IIIII 140 F ( 60 C)IIIA 140 F - 200 F( 60 C - 93 C)IIIB 200 F ( 93 C)2

NFPA 30 Reorganized in 2008Old Chapters1 - 3 Administrative4 Tank Storage5 Piping6 Container Storage7 Operations8 ElectricalNew Chapter Groups1 - 4 Administrative5 - 8 General Requirements9 - 16 Container Storage17 - 20 Operations21 - 26 Tank Storage27 - 29 Piping, Bulk TransferBulk Storage Tanks1 - 4 Administrative5 - 8 GeneralRequirements9 - 16 Container Storage17 - 20 Operations21 - 26 Tank Storage27 - 29 Piping, BulkTransfer21 Requirements for AllTanks22 Aboveground Tanks23 Underground Tanks24 Storage Tank Bldgs.25 Storage Tank Vaults26 ReservedTypes of Storage Tankssingle wallclosed-top dikedouble wallfire resistant orprotected3

Chapter 21 – General applies to storage of flammable andcombustible liquids in fixed tanks exceeding 60 gal. (230L) portable tanks and IBC’S 793 gal.(3,000 L) portable tanks connected to fixed piping not used for processingChapter 21 – General basic design requirements tank can be of any shape, size or type must be constructed per recognizedengineering standards aboveground tanks cannot be used asunderground tanks nor vice versaChapter 21 – General materials of construction recognized engineering standards for thematerial of construction being used steel or other approved noncombustiblematerial must be compatible with liquid stored can be lined, if necessary special engineering required ifspecific gravity of liquid 1.04

Chapter 21 – General combustible materials of constructionpermitted: underground where required by liquid properties Class IIIB liquids: outside aboveground where not exposedto a spill/leak of Class I or Class II liquid. inside a building protected by anautomatic fire-extinguishing system.Chapter 21 – General common design standards API Standard 650, Welded Steel Tanks UL 58, Underground Tanks UL 80, Steel Tanks for Oil Burner Fuel UL 142, Steel Aboveground Tanks UL 1316, FGRP Underground Storage Tanks UL 1746, External Corrosion ProtectionSystems for Steel Underground Tanks UL 2080, Fire Resistant Tanks UL 2085, Protected Aboveground Tanks1.14Chapter 21 – General maximum operating pressures for ambientpressure tanks 0.5 psi gauge for vertical cone rooftanks 1.0 psi gauge, if designed to Appendix Fof API Standard 650 1.0 psi gauge for horizontal cylindricalor rectangular tanks5

Chapter 21 – General maximum operating pressures for lowpressure tanks: 1.0 to 15 psi API 620, Large,Welded,, Low-PressureStorage Tanks ASME Code forUnfired PressureVessels, Section VIII,Division 1Chapter 21 – General maximum operating pressures forpressure vessels: 15 psi ASME Code forUnfired PressureVessels, Section VIII,Division 1 or 2Chapter 21 – General ventmust prevent vacuum or pressure that:distort the roof of a cone roof tank can exceed the design pressure of the tank maximum rate of flow,flow in or out atmospheric or temperature changes size vent per API 2000 or approved standard min 1 ¼ in. (32 mm) or largest connection. can6

Chapter 21 – General vent termination devices for Class IA liquids: normally closed venting devices pressure-vacuum (conservation vent)typical pressure-vacuum ventChapter 21 – General vent termination devices forClass IB and Class IC liquids normally-closed venting devices listed flame arresters novent termination devicesrequired for Class II orClass III liquids7

Chapter 21 – General protection from internal corrosion additional metal thickness approved protective coatings or liningsThis tank failed at theweld between the shelland the tank bottomdue to corrosion.1.22Chapter 21 – General testing requirements Shop-built and site-built tanks must betested before being placed in service. use tank construction standard listed tanks exempt Tightness Test (21.6) for site-built tanks, test above issufficient use water or air – 3 to 5 psigChapter 21 – General fire hazard analysis required fire & explosion hazards on the site local conditions threat from adjacent properties environmental conditions fire protection systems where indicated emergency action plan training and drills inspection and maintenance8

Chapter 21 – General overfill prevention procedures / systems required for tanks 1,320 gal. (5,000 L)storing Class I or Class II liquids aboveground tanks receiving /transferring Class I liquids from pipelinesor marine vessels must have writtenproceduresChapter 21 – General identification and security NFPA 704 placard unsupervised, isolated abovegroundtanks must be secured from tampering ortrespassingChapter 21 – General tanks in areas subject to floods must havemeans to secure tank from displacementTanks after Hurricane Katrina9

Ch. 22 – Aboveground Tanks covers tanks installed above grade,at grade, below grade without backfillCh. 22 – Aboveground Tanks tank supports and foundation design to minimize excessive loading atsupports and to minimize uneven settling design for earthquakes on ground or on supports of masonry,concrete or steelCh. 22 – Aboveground Tanks location (siting) of aboveground tanks separation distance from nearest important building near and far side of public way property line that is or can be built upon shell-to-shell spacing10

Ch. 22 – Aboveground Tanks factors that determine separation type of tank floating roof vertical w/ weak roof-to-shell seam horizontalhori ontal or verticalertical withithemergency relief vents* Protected tank protection for the tank itself protection for exposed property*predicated on maximum 2.5 psi overpressureCh. 22 – Aboveground TanksLiquidTable(s)Class I, II, IIIA stable liquids(up to 2.5 psi) & I, II, IIIA stable liquids( 2.5 psi)liquids w/ boil-over characteristics22.4.1.3 & liquids22.4.1.5 & IIIB stable liquids22.4.1.6Table (a)Minimum DistanceTank Typefloating roofvertical withweakk roof-toftshell seamProtectionProperty Linefor exposed property½ DiameternoneDiameter, 175’ maxapproved foam or inertgas systemt(150’ max))Important Bldg1/6Diameter½ Diameter1/6Diameterfor exposed property1 X Diameter1/3Diameternone2 X Diameter(350’ max)1/3Diametertanks withemergencyrelief venting,2.5 psi maxapproved foam or inertgas system (150” max)½ X Table exposed property1 X Table X Table½ Table

Table (b)Capacity, galImportant Bldg. orPublic Way ft (m)Property Line, ft 27555276 – 750105751 – 12,00015512,001 – 30,00020530,001 – 50,000301050,001 – 100,0005015100,001 – 500,0008025500,001 – 1,000,000100351,000,001 – 2,000,000135452,000,001 – 3,000,00016555 3,000,00017560Other Liquids other tables for: aboveground tanks, stable liquids,pressure 2.5 psig aboveground tanks, boilboil-overover liquids aboveground tanks, unstable liquids aboveground tanks, Class IIIB liquidsTable — Shell to Shell SpacingDiameter, ft. 150 150 w/remoteimpoundingopen dikeFloating Roof Tanks1/6 adjacent diameters1/6 adjacent diameters1/4 adjacent diametersFixed Roof & HorizontalClass I /IIClass IIIA1/6 adjacent diameters1/4 AD1/6 AD1/3 AD1/4 ADIn no case is the separation allowed to be less than 3 ft.12

Ch. 22 – Aboveground TanksEmergency relief venting:A means to automaticallyrelieve excess pressureinside a tank due toexposure from an externalfire.Not intended for pressurerelief from internalexplosion or internaloverpressure.Ch. 22 – Aboveground Tanks emergency relief venting tanks must have additional ventingcapacity to prevent the tank fromexceedingg 2.5 psigp g if exposedpto fire can use floating roof, lifter roof, weakroof-to-shell seam, loose-bolt cover, oremergency vent device13

Weak roof-to-shell seam design optionsEmergency VentCh. 22 – Aboveground Tanks emergency relief venting is required for: every compartment of a compartmentedtank Interstitial space of a secondarycontainment-type tank Exception: Tanks storing Class IIIBliquids that exceed 285 bbl (11,900 gal)and not located within the diked area ordrainage path of tanks storing Class I orClass II liquids.14

Ch. 22 – Aboveground Tanks spill control – general tanks holding Class I, II, or IIIA liquidsmust prevent accidental release fromendangering important facilities,adjoiningjg property,p p y, and waterwaysy remote impounding impounding around tanks by diking combined remote impounding anddiking closed-top diking secondary containment tanksRemote Impounding100,000 gal50 ft min50 ftmin1% slopefor 50 ft100,000 galImpounding by Diking15

Impounding by DikingCh. 22 - Aboveground Tanks spill control – diking 1% slope from tank to dike wall for 50 ft. dike capacity the greatest volume ofqu d tthatat cacan be releasede eased fromo thet e largesta gestliquidtank (overflow point) local law might require more capacity calculated by deducting fromgross volume of diked area the volume ofall enclosed tanks below height of dike wall,except for the largest tankCh. 23 - Underground Tanks1.4816

Ch. 23 - Underground Tanks general installation requirements must be installed in accordance withmanufacturer’s instructions excavation must not underminefoundations or footings of existingstructures tanks must not be damaged duringdelivery, unloading, or placement into theexcavationCh. 23 - Underground Tanks tank location tank must be situated, with respect toexisting foundations, footings, andsupports,ppso that loads are nottransmitted to the tank itselfBasement or PitClass IClass II1 ft1 ftProperty Line3 ft1 ft17

Ch. 23 - Underground Tanks top cover where tank is not subject tovehicle traffic 24 in. of clean backfill, or 12 in. of compacted backfill plus4 in. minimum slab of reinforced concreteCh. 23 - Underground Tanks top cover where tank IS subject to vehicletraffic 36 in. of clean backfill, or 18 in. min. of compacted backfill plus6 in. min. slab of reinforced concrete 18 in. min. of compacted backfill plus8 in. min. slab of asphalt/aggregateconcrete top pad must extend at least 12 in.beyond the footprint of the tank18

Ch. 23 - Underground Tanks maximum burial depth as specified by the tank manufacturer consult tank manufacturer aboutnecessary reinforcing if: burial depth exceeds diameter of tank pressure at bottom of tank willexceed 10 psi specific gravity of the liquid stored mustbe considered as a design factorCh. 23 - Underground Tanks normal (breather) venting sufficient capacity to prevent blowback ofvapor or liquid at the fill opening while thetank is beingg filled size vent pipe per Table 23.5.2 minimum 1¼ in. (32 mm) based on maximum flowrate lengths of pipe runs to 200 ft.Ch. 23 - Underground Tanks external corrosion protection a properly engineered, installed, andmaintained cathodic protection system approved or listed corrosioncorrosion-resistantresistantmaterials or systems. type of protection used based oncorrosion history of the area andjudgment of a qualified engineer19

Ch. 23 - Underground Tankstank openings other than vents connections must be liquid & vapor tight gauge openings must have liquid & vaportight caps or covers covers kept closed when not in use inside building, protect each openingagainst liquid overflow and vapor release use a spring-loaded check valve orother approved device Ch. 23 - Underground Tanks tank openings other than vents fill and discharge lines can enter tankonly through the top slope fill lines toward the tank tanks for Class I liquids with a capacity 1,000 gal. must have a tight fill devicefor connecting the fill hose to the tankCh. 23 - Underground Tanks see Section 23.14 for requirements tanks must be anchored so that theycannot float out of the ground whensubjectedjto maximum groundwaterglevelor flood stage20

NFPA 30A, Table

Questions?Contact InformationBob BenedettiTelephone: 617-984-7433617-571-8494 (cell) Telefax:617-984-7110 E-Mail:[email protected] 22

Table from NFPA 30A-2008, Code for Motor FuelDispensing Facilities and Repair Garages

Exhibit II.4.3 fromFlammable and Combustible Liquids Code Handbook,Seventh Edition

Table Location of Aboveground Storage Tanks Storing Stable Liquids — Internal Pressure Not toExceed a Gauge Pressure of 2.5 psi (17 kPa)Type of TankFloating roofProtectionProtection for exposuresbNoneVertical with weak roof-toshell seamApproved foam or inertingsystemc on tanks not exceedingMinimum Distance (ft)From Nearest SideFrom Property Line That Isof Any Public Wayor Can Be Built Upon,or from NearestIncluding the Opposite SideImportant Buildingof a Public Wayaon the SamePropertya½ diameter of tank1/6 diameter of tankDiameter of tank but need notexceed 175 ft½ diameter of tank1/6 diameter of tank1/6 diameter of tankDiameter of tank1/3 diameter of tank2 diameter of tank but neednot exceed 350 ft½ value in Table diameter of tankValue in Table in Table22.4.1.1(b)Value in Table22.4.1.1(b)½ value in Table22.4.1.1(b)150 ft in diameterdProtection for exposuresbNoneHorizontal and vertical tanks Approved inerting systemb onwith emergency reliefthe tank or approved foamventing to limit pressures to system on vertical tanks2.5 psi (gauge pressure of17 kPa)Protection for exposuresbProtected aboveground tankNone2 value in Table½ value in Table½ value in Table22.4.1.1(b)For SI units, 1 ft 0.3 m.aThe minimum distance cannot be less than 5 ft (1.5 m).bSee definition 3.3.42, Protection for Exposures.cSee NFPA 69, Standard on Explosion Prevention Systems.dFor tanks over 150 ft (45 m) in diameter, use “Protection for Exposures” or “None,” as applicable.Table Reference Table for Use with Tables,, and Capacity (gal)275 or less276 to 750751 to 12,00012,001 to 30,00030,001 to 50,00050

can distort the roof of a cone roof tank can exceed the design pressure of the tank maximum rateofflowinoroutrate of flow, in or out atmospheric or temperature changes size vent per API 2000 or approved standard min 1 ¼ in. (32 mm) or largest connection.