Division B
Acceptable Solutions

Part 4 — Flammable and Combustible Liquids

Section 4.3. Tank Storage

4.3.1. Design, Construction and Use of Storage Tanks

4.3.1.1. Application
1) Intent StatementThis Section applies to storage tanks for flammable liquids and combustible liquids.
4.3.1.2. Atmospheric Storage Tanks
1) Intent StatementExcept as permitted in Sentence (3) and in Section 4.10., atmospheric storage tanks shall be built in conformance with the following:
a) API 12B, “Bolted Tanks for Storage of Production Liquids,”
b) API 12D, “Field Welded Tanks for Storage of Production Liquids,”
c) API 12F, “Shop Welded Tanks for Storage of Production Liquids,”
d) API 650, “Welded Tanks for Oil Storage,”
e) CAN/ULC-S601, “Shop Fabricated Steel Aboveground Tanks for Flammable and Combustible Liquids,”
f) CAN/ULC-S602, “Aboveground Steel Tanks for Fuel Oil and Lubricating Oil,”
g) ULC-S603, “Steel Underground Tanks for Flammable and Combustible Liquids,”
h) CAN/ULC-S603.1, “External Corrosion Protection Systems for Steel Underground Tanks for Flammable and Combustible Liquids,”
i) ULC-S615, “Reinforced Plastic Underground Tanks for Flammable and Combustible Liquids,”
j) CAN/ULC-S652, “Tank Assemblies for the Collection, Storage and Removal of Used Oil,”
k) CAN/ULC-S653, “Aboveground Steel Contained Tank Assemblies for Flammable and Combustible Liquids,”
l) ULC-S655, “Aboveground Protected Tank Assemblies for Flammable and Combustible Liquids,” or
m) ULC/ORD-C142.5, “Concrete Encased Steel Aboveground Tank Assemblies for Flammable and Combustible Liquids.”
2) Intent StatementTanks built in conformance with Clauses (1)(a), (b) and (c) shall be used only for the storage of crude petroleum at oil fields.
3) Intent StatementWhen necessitated by possible contamination of the liquid to be stored or possible rapid corrosion of the tank, storage tanks need not conform to Sentence (1), provided that they are designed and built in conformance with good engineering practice for the material being used.
4) Intent StatementAtmospheric storage tanks shall not be used for the storage of flammable liquids or combustible liquids at temperatures at or above their boiling points.
4.3.1.3. Low Pressure Storage Tanks and Pressure Vessels
1) Intent StatementLow pressure storage tanks shall be constructed in conformance with
a) API 620, “Design and Construction of Large, Welded, Low-Pressure Storage Tanks,” or
b) ASME 2007, “Boiler and Pressure Vessel Code.”
2) Pressure vessels shall be constructed in conformance with the British Columbia Power Engineers, Boiler, Pressure Vessel and Refrigeration Safety Regulation.

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3) Intent StatementLow pressure storage tanks and pressure vessels are permitted to be used as atmospheric storage tanks.
4.3.1.4. Operating Pressure
1) Intent StatementThe normal operating pressure of a storage tank shall not exceed its design pressure.
4.3.1.5. Corrosion Protection
1) Intent StatementThe exposed surface of every aboveground storage tank for flammable liquids or combustible liquids that is fabricated of any ferrous substance shall be thoroughly coated with a rust-resisting material that is compatible with the tank.
4.3.1.6. Floating Roofs
1) Intent StatementExcept for perimeter sealing material, floating roof assemblies or internal floating covers installed in storage tanks shall be constructed of metal or other materials and designed in conformance with one of the tank construction standards listed in this Subsection.
4.3.1.7. Identification
1) Intent StatementA storage tank and its filling and emptying connections shall be identified in conformance with CPPI 1990, “Using the CPPI Colour-Symbol System to Mark Equipment and Vehicles for Product Identification.”
4.3.1.8. Overfill Protection
1) Intent Statementchange beginExcept as required in Sentence (2),change end a storage tank shall be prevented from being overfilled by providing
a) continuous supervision of the filling operations by personnel qualified to supervise such operations, or
b) an overfill protection device conforming to change beginULC-S661, “Overfill Protection Devices for Flammable and Combustible Liquid Storage Tanks”change end (see Appendix A).
2) Intent Statementchange beginTight-filled storage tanks shall be prevented from being overfilled by providing a positive shut-off device conforming to ULC-S661, “Overfill Protection Devices for Flammable and Combustible Liquid Storage Tanks” (See Appendix A.)change end
4.3.1.9. Installation and Use
1) Intent StatementUnless otherwise specified in this Code, a storage tank shall be installed and used in conformance with the applicable installation and use provisions of the design document to which the storage tank was built as required by this Section.
4.3.1.10. Reuse
1) Intent StatementA storage tank that has been taken out of service shall not be reused for the storage of flammable liquids or combustible liquids unless it has been
a) refurbished so as to conform to one of the standards listed in Sentence 4.3.1.2.(1), or
b) refurbished in conformance with Sentence (2) or (3).
2) Intent StatementA storage tank is permitted to be refurbished for aboveground use in conformance with one of the following standards:
a) ULC-S601(A), “Refurbishing of Steel Aboveground Horizontal Tanks for Flammable and Combustible Liquids,”
b) ULC-S630(A), “Refurbishing of Steel Aboveground Vertical Tanks for Flammable and Combustible Liquids.”
3) Intent StatementA storage tank is permitted to be refurbished for underground use in conformance with one of the following standards:
a) ULC-S603(A), “Refurbishing of Steel Underground Tanks for Flammable and Combustible Liquids,”
b) ULC-S615(A), “Refurbishing of Reinforced Plastic Underground Tanks for Flammable and Combustible Liquids.”
change begin(See Appendix A.)change end
4) Intent StatementA riveted storage tank shall not be relocated.

4.3.2. Installation of Outside Aboveground Storage Tanks

4.3.2.1. Location
1) Intent StatementEvery outside aboveground storage tank for the storage of flammable liquids or combustible liquids shall be located in conformance with Sentences (2) to (5) with respect to a property line or a building on the same property.
2) Intent StatementExcept as provided in Sentences (6) and (7), every aboveground storage tank containing stable liquids and having a working pressure of not more than 17 kPa (gauge) shall be separated from a property line or a building on the same property by distances
a) half those in Table 4.3.2.1., where protection is provided against fire or explosion in the tank in conformance with Sentence 4.3.2.5.(2), or
b) equal to those in Table 4.3.2.1., where protection referred to in Clause (a) is not provided.
Table 4.3.2.1.
Location of Aboveground Storage Tanks
Forming part of Sentences 4.3.2.1.(2), (3) and (4), and 4.9.2.1.(2) and (3)
Maximum Tank Capacity, L

Minimum Distance to a Property Line or to a Building on the Same Property, m

250 000 3
500 000 4.5
2 500 000 9
5 000 000 12
over 5 000 000 15
3) Intent StatementEvery aboveground storage tank containing unstable liquids and having a working pressure of not more than 17 kPa (gauge) shall be separated from a property line or a building on the same property by distances
a) equal to those in Table 4.3.2.1., but not less than 7.5 m, where protection is provided against fire or explosion in the tank in conformance with Sentence 4.3.2.5.(2), or
b) 3 times those in Table 4.3.2.1., but not less than 15 m, where protection referred to in Clause (a) is not provided.
4) Intent StatementEvery aboveground storage tank containing boil-over liquids shall be separated from a property line or a building on the same property by distances
a) 0.75 times those in Table 4.3.2.1., where protection is provided against fire or explosion in the tank in conformance with Sentence 4.3.2.5.(2), or
b) equal to those in Table 4.3.2.1., where protection referred to in Clause (a) is not provided.
(See Appendix A.)
5) Intent StatementWhere a storage tank containing stable liquids or unstable liquids has a working pressure greater than 17 kPa (gauge), the distances from a property line or a building on the same property shall be those specified in Sentences (2) and (3) multiplied by 1.5, but shall be not less than 7.5 m.
6) Intent StatementThe minimum distance required in Sentence (2) from a storage tank containing only Class II or IIIA liquids to a building on the same property is permitted to be reduced to
a) 1.5 m provided the tank capacity is not more than 50 000 L, or
b) zero provided the tank capacity is not more than 2 500 L.
7) Intent StatementThe minimum distance required in Sentence (2) is permitted to be waived provided the storage tank is in conformance with ULC-S655, “Aboveground Protected Tank Assemblies for Flammable and Combustible Liquids.”
8) Intent StatementWhere end failure of horizontal storage tanks may endanger adjacent property, the tanks shall be placed with the longitudinal axis parallel to such property.
4.3.2.2. Spacing between Storage Tanks
1) Intent StatementExcept as required in Sentences (2) and (3) and in Article 4.3.2.3., the minimum distance between every combination of 2 aboveground storage tanks shall be 0.25 times the sum of their diameters, but shall be not less than 1 m.
2) Intent StatementThe minimum distance between any 2 storage tanks, neither of which has a capacity of more than 250 000 L, shall be 1 m.
3) Intent StatementWhere either of 2 aboveground storage tanks contains unstable liquids, the distance required in Sentences (1) and (2) shall be doubled.
4.3.2.3. Clearances from Liquefied Petroleum Gas Cylinders and Tanks
1) Intent StatementThe minimum separation between a flammable liquid or combustible liquid storage tank and a liquefied petroleum gas cylinder or tank shall be 6 m.
2) Intent StatementSecondary containments for flammable liquid and combustible liquid storage tanks shall not contain any liquefied petroleum gas cylinder or tank, and the centre line of the secondary containment wall shall be not less than
a) 3 m away from a liquefied petroleum gas cylinder, and
b) 6 m away from a liquefied petroleum gas tank.
4.3.2.4. Fire Department Access
1) Intent StatementExcept as provided in Sentences (2) and (3), storage tanks for flammable liquids or combustible liquids shall be spaced so that each storage tank is accessible for firefighting purposes.
2) An access route constructed in conformance with Subsection 3.2.5. of Division B of the British Columbia Building Code shall be provided in outdoor storage areas to permit the approach of fire department vehicles to within 60 m travelling distance of any storage tank.

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3) Intent StatementWhere firefighting access to storage tanks containing Class I or II liquids is not provided, fire extinguishing measures conforming to Sentence 4.3.2.5.(2) shall be provided.
4.3.2.5. Fire Protection Systems
(See Appendix A.)
1) Intent StatementWhere the diameter of a storage tank exceeds 45 m, the storage tank shall be provided with protection against fires or explosions in conformance with Sentence (2).
2) Intent StatementProtection against fires or explosions required for a storage tank shall consist of fixed protection systems designed in conformance with good engineering practice such as that described in
a) NFPA 11, “Low-, Medium-, and High-Expansion Foam,”
b) NFPA 15, “Water Spray Fixed Systems for Fire Protection,” and
c) NFPA 69, “Explosion Prevention Systems.”

4.3.3. Supports, Foundations and Anchorage for Aboveground Storage Tanks

4.3.3.1. Foundations and Supports
1) Intent StatementStorage tanks shall rest on the ground or on foundations, supports or piling made of concrete, masonry or steel.
2) Intent StatementTank supports shall be installed on firm foundations designed to minimize uneven settling of the tank and to minimize corrosion of the part of the tank resting on the foundation.
3) Intent Statementchange beginWhere the clearance below the base of the tank exceedschange end 300 mm, change begintank supportschange end shall have a minimum fire-resistance rating of 2 h.
4) Intent StatementEvery aboveground storage tank shall be supported in a manner that will prevent the allowable design stress of the tank from being exceeded.
4.3.3.2. Earthquake Protection
1) In areas subject to earthquake forces, storage tanks, supports and connections shall be designed to resist such forces in conformance with
a) Part 4 of Division B of the British Columbia Building Code, and
b) Appendix change beginA2 of CAN/ULC-S601, “Shop Fabricated Steel Aboveground Tanks for Flammable and Combustible Liquids.”change end

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4.3.3.3. Protection against Flooding
1) Intent StatementWhen aboveground storage tanks are located in an area that is subject to flooding, the tanks shall be securely anchored to prevent floating.

4.3.4. Normal and Emergency Venting for Aboveground Storage Tanks

4.3.4.1. Design and Installation
1) Intent StatementAtmospheric and low pressure storage tanks shall be provided with normal and emergency venting in conformance with
a) API 2000, “Venting Atmospheric and Low-Pressure Storage Tanks: Nonrefrigerated and Refrigerated,” or
b) the tank design standards listed in Sentence 4.3.1.2.(1).
4.3.4.2. Unstable Liquids
1) Intent StatementWhen unstable liquids are stored, the effects of heat or gas resulting from polymerization, decomposition, condensation or self-reactivity shall be allowed for in the determination of the total venting capacity.

4.3.5. Vent Piping for Aboveground Storage Tanks

4.3.5.1. Materials and Construction
1) Intent StatementExcept at distilleries covered in Section 4.10., vent piping materials and construction shall conform to Subsections 4.5.2., 4.5.3. and 4.5.5.
4.3.5.2. Location of Vent Pipe Outlets
1) Intent StatementNormal vent pipe outlets for storage tanks of Class I liquids
a) shall be located outside buildings not less than
i) 3.5 m above the adjacent ground level, and
ii) 1.5 m from any building opening, and
b) shall discharge so that flammable vapours will not enter the building or be trapped near any part of the building.
2) Intent StatementNormal vent pipe outlets for storage tanks of Class II or IIIA liquids shall discharge outside buildings not less than
a) 2 m above the adjacent ground level, and
b) 1.5 m from any building opening.
3) Intent StatementEmergency vent outlets for storage tanks shall discharge outside buildings not less than 1.5 m from any building opening and from any combustible component of any building's exterior wall.
4.3.5.3. Interconnection of Vent Piping
1) Intent StatementExcept as provided in Sentence (2), 2 or more storage tanks are permitted to be connected to a common vent pipe for normal relief venting provided the vent pipe size is designed to vent the combined vapours produced in the connected tanks without exceeding the allowable stresses of the tanks.
2) Intent StatementVent piping for storage tanks for Class I liquids shall not be connected to vent piping for storage tanks for Class II or IIIA liquids unless an effective arrangement is provided to prevent the vapours from the Class I liquids from entering the other tanks.

4.3.6. Openings Other than Vents in Aboveground Storage Tanks

4.3.6.1. Provision of Valves
1) Intent StatementEach connection to an aboveground storage tank through which the liquid can normally flow shall be provided with an internal or external shut-off valve located as close as practical to the shell of the tank.
2) Intent StatementEach connection to an aboveground storage tank that is below the liquid level and through which liquid does not normally flow shall be provided with a liquid-tight closing device.
4.3.6.2. Materials
1) Intent StatementValves and their connections to a storage tank shall be made of steel, except that when the chemical characteristics of the liquid stored are incompatible with steel, materials other than steel are permitted to be used.
2) Intent StatementMaterials for valves and their connections to a storage tank shall be suitable for the pressures, stresses and temperatures that may be expected, including those of possible fire exposure.
4.3.6.3. Openings for Liquid Level Measurements
1) Intent StatementOpenings for measuring liquid levels in storage tanks for Class I liquids shall be equipped with caps or covers which shall be opened only when measuring the liquid level.
4.3.6.4. Connections for Filling and Emptying
1) Intent StatementExcept as provided in Sentence (3), connections used as part of normal operating conditions for filling or emptying storage tanks for flammable liquids and combustible liquids shall be located
a) outside buildings,
b) at a location free of sources of ignition, and
c) not less than 1.5 m away from building openings.
2) Intent StatementConnections for filling or emptying storage tanks shall be kept closed to prevent leakage when not in use.
3) Intent StatementA filling connection described in Sentence (1) is permitted to be located inside a building if
a) this is made necessary
i) by a process or activity located indoors and to which the tank is directly associated, or
ii) for the collection of used liquids, and
b) the fill piping is provided with means to prevent flammable vapours from returning to the building.

4.3.7. Secondary Containment for Aboveground Storage Tanks

4.3.7.1. General
1) Intent StatementThe area surrounding a storage tank or group of storage tanks shall be designed to accommodate accidental spillage in conformance with Subsection 4.1.6.
2) Intent StatementWhere barriers described in Sentence 4.1.6.1.(1) are provided to contain accidental spillage from aboveground storage tanks, they shall conform to the requirements for secondary containment in this Subsection.
3) Intent StatementA storage tank conforming to Sentence 4.3.7.4.(2) shall be considered as conforming to this Subsection provided it is used and maintained in conformance with Articles 4.3.7.8. and 4.3.7.9.
4.3.7.2. Construction
1) Intent StatementExcept as provided in Sentence (2), the base and walls of a secondary containment shall be made of noncombustible materials, and shall be designed, constructed and maintained to
a) withstand full hydrostatic head, and
b) provide a permeability of not more than 10-6 cm/s to the flammable liquids or combustible liquids contained in the storage tanks.
2) Intent StatementWhere a membrane providing the level of impermeability required in change beginClause (1)(b) is combustible, it shall be covered with a noncombustible material of such nature and thickness that the membrane will not fail when the secondary containment is exposed to fire.change end
3) Intent StatementExcept as provided in Sentence (4), openings shall not be permitted in a secondary containment.
4) Intent StatementWhere piping passes through a secondary containment, such passages shall conform to Sentences (1) and (2).
4.3.7.3. Capacity
(See A-4.1.6.1.(1) in Appendix A.)
1) Intent StatementExcept as permitted in Sentence (3), a secondary containment for a single storage tank shall have a volumetric capacity of not less than 110% of the capacity of the tank.
2) Intent StatementExcept as permitted in Sentence (3), a secondary containment for more than one storage tank shall have a volumetric capacity of not less than the sum of
a) the capacity of the largest storage tank located in the contained space, and
b) 10% of the greater of
i) the capacity specified in Clause (a), or
ii) the aggregate capacity of all other storage tanks located in the contained space.
3) Intent StatementWhen the secondary containment is designed to prevent the entry of precipitation and water used for firefighting purposes into the contained space, it shall have a volumetric capacity of not less than the capacity of the largest storage tank located in the contained space.
4.3.7.4. Clearances
1) Intent StatementExcept as provided in Sentence (2), no part of a secondary containment wall shall be less than 1.5 m from a storage tank shell.
2) Intent StatementIt is permitted to waive the distance required in Sentence (1) provided the storage tank
a) is constructed in accordance with
i) Clauses 4.3.1.2.(1)(j), (k), (l) or (m), incorporating secondary containment, or
ii) Clause 4.3.1.2.(1)(e) for double-walled storage tanks,
b) has a capacity of not more than 50 000 L, and
c) is protected by posts or guardrails when exposed to collision damage.
4.3.7.5. Access to Storage Tanks and Ancillary Equipment
1) Intent StatementA secondary containment shall permit
a) access to storage tanks, valves and ancillary equipment,
b) egress from the contained space, and
c) access for firefighting as specified in Article 4.3.2.4.
(See Appendix A.)
2) Intent StatementWhere a storage tank contains Class I liquids, provisions shall be made for the normal operation of valves and for access to the storage tank roof without entering the contained space created by the secondary containment when
a) the average height of the secondary containment exceeds 3.5 m, measured from the ground level of the interior of the contained area, or
b) the distance between the tank shell and the top inside edge of the secondary containment wall is less than the height of this wall.
(See Appendix A.)
4.3.7.6. Emergency Venting
1) Intent StatementWhere the secondary containment is not open to the atmosphere, emergency venting shall be provided to relieve any buildup of internal pressure in the contained space when exposed to heat or fire.
4.3.7.7. Leak Detection
1) Intent StatementWhere the contained space created by the secondary containment is not accessible for an internal visual examination, change beginand the secondary containment is not sloped so as to permit liquid to flow to a specific location that can be monitoredchange end, a monitoring device shall be provided to indicate the loss of integrity of the secondary containment.
4.3.7.8. Drainage
1) Intent StatementLiquids, debris and precipitation shall not accumulate in the contained space created by the secondary containment.
2) Intent StatementProvisions shall be made for removing liquid from the secondary containment in conformance with Subsection 4.1.6.
3) Intent StatementControls for the liquid removal system required in Sentence (2) shall be
a) normally closed,
b) accessible under fire exposure conditions, and
c) located so they can be operated from outside the contained space.
4.3.7.9. Use of Secondary Containment
1) Intent StatementThe contained space created by a secondary containment shall not be used for storage purposes.

4.3.8. Installation of Underground Storage Tanks

4.3.8.1. change beginConstruction
1) Intent StatementStorage tanks installed underground shall be of double-walled construction and shall be built in conformance with the underground storage tank standards identified in Sentence 4.3.1.2.(1).change end
4.3.8.2. Location
1) Intent StatementUnderground storage tanks shall be located so that loads from building foundations and supports are not transmitted to the tank.
2) Intent StatementUnderground storage tanks shall be separated by a horizontal distance of not less than
a) 600 mm from adjacent underground tanks or structures,
b) 1 m from a building foundation or a street line, and
c) 1.5 m from other property lines.
4.3.8.3. Ground Cover
1) Intent StatementExcept as required in Sentences (2) to (4), underground storage tanks shall be installed with not less than 600 mm of ground cover over the tank.
2) Intent StatementExcept as required in Sentence (3), storage tanks subjected to vehicular traffic shall be installed not less than 1 m below finished ground level.
3) Intent StatementEither a 150 mm reinforced concrete slab or a 200 mm unreinforced concrete slab over not less than 450 mm of sand is permitted in lieu of the protection described in Sentence (2) provided the slab extends at least 300 mm beyond the storage tank.
4) Intent StatementWhere subsurface conditions make it impracticable to install a storage tank totally below adjacent ground level, an underground storage tank shall be installed so that at least
a) 75% of its mass is below adjacent ground level provided there is not less than 600 mm of ground cover over the portion of the tank above adjacent ground level, or
b) 50% of its mass is below adjacent ground level provided there is not less than 1 m of ground cover over the portion of the tank above adjacent ground level.
4.3.8.4. Damage Repair
1) Intent StatementUnderground storage tanks that are in the process of being installed shall be inspected, and any damage to the tank shell, protective coating, fittings or anodes shall be repaired before they are lowered into the excavation.
2) Intent StatementDamage to storage tank shells shall not be repaired on site.
4.3.8.5. Damage Prevention
1) Intent StatementUnderground storage tanks shall be lowered into the excavation by the use of lifting lugs and hooks and, where necessary, spreader bars to prevent damage to the tank shell, protective coating, fittings or anodes.
2) Intent StatementAny method of handling that might result in damage to the protective coating of the tank shall not be used.
4.3.8.6. Installation
1) Intent StatementUnderground steel storage tanks shall be installed in conformance with Appendix A of CAN/ULC-S603.1, “External Corrosion Protection Systems for Steel Underground Tanks for Flammable and Combustible Liquids.”
2) Intent StatementUnderground reinforced plastic storage tanks shall be installed in conformance with Appendix A of ULC-S615, “Reinforced Plastic Underground Tanks for Flammable and Combustible Liquids.”
3) Intent StatementUnderground storage tanks shall not be placed in direct contact with reinforced concrete slabs but shall be separated by not less than 150 mm of sand or other suitable material to evenly distribute the weight of the tank on the supporting base.
4.3.8.7. Filling
1) Intent StatementFlammable liquids or combustible liquids shall not be placed in an underground storage tank until
a) the fill pipe and vent line have been installed in the tank, and
b) all other openings have been sealed.
4.3.8.8. Spillage
1) Intent StatementIf a spillage occurs, the escaped liquid and all soil contaminated by the spill shall be removed in conformance with Subsection 4.1.6.
4.3.8.9. Anchorage
1) Intent StatementUnderground storage tanks shall be protected against hydrostatic forces which can cause the uplift of the tanks once they are empty. (See Appendix A.)
2) Intent StatementWhere anchors and ground straps are used to resist the uplift forces referred to in Sentence (1), they shall be
a) electrically isolated from the tank, and
b) installed in such a manner that they do not damage the tank's shell, protective coating, fittings or anodes.

4.3.9. Sumps

4.3.9.1. change beginInstallation
1) Intent StatementA dispenser sump shall be provided under a dispenser, unless the dispenser is located on top of an aboveground storage tank.
2) Intent StatementA spill containment sump shall be provided at every underground storage tank fill point.
3) Intent StatementA transition sump shall be provided for all mechanical pipe connections located below grade.
4) Intent StatementA turbine sump shall be provided for all turbine pump assemblies located below grade or above grade where they are not readily visible.
5) In addition to the requirements of change beginArticle 4.3.9.2.change end, the sumps referred to in Sentences (1) to (4) shall be installed in conformance with the sump manufacturer’s instructions.

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4.3.9.2. change beginConstruction
1) Dispenser sumps shall conform to the construction and performance requirements of ULC/ORD-C107.21, “Under-Dispenser Sumps.”
2) Spill containment sumps shall canfaIDl to the construction and performance requirements of ULC/ORD-C58.19, “Spill Containment Devices for Underground Flammable Liquid Storage Tanks.”
4.3.9.3. Leak Detection Monitoring
1) Where dispenser sumps, turbine sumps and transition sumps referred to in Article 4.3.9.1. are used in underground applications, they shall be provided with an electronic monitoring device to indicate the presence of liquid.change end

4.3.10. Corrosion Protection of Underground Steel Storage Tanks

4.3.10.1. Corrosion Protection
1) Intent StatementUnderground steel storage tanks and change beginintegral fittingschange end subject to corrosion shall be
a) protected in conformance with CAN/ULC-S603.1, “External Corrosion Protection Systems for Steel Underground Tanks for Flammable and Combustible Liquids,” or
b) change beginprotected by impressed current in conformance with NACE RP0285, “Corrosion Control of Underground Storage Tank Systems by Cathodic Protection.”change end
4.3.10.2. change beginBC Deletionchange end

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4.3.10.3. change beginBC Deletionchange end

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4.3.11. Vents for Underground Storage Tanks

4.3.11.1. Vent Design
1) Intent StatementUnderground storage tanks shall be provided with vent openings and piping of sufficient cross-sectional area designed to vent the tanks during the maximum filling or withdrawal rate without causing the allowable stress for the tank to be exceeded.
4.3.11.2. Materials and Construction
1) Intent StatementExcept at distilleries covered in Section 4.10., vent piping materials and construction shall conform to Subsections 4.5.2., 4.5.3. and 4.5.5.
4.3.11.3. Installation
1) Intent StatementVent pipe outlets from underground storage tanks for Class I liquids
a) shall be located outside buildings higher than the fill pipe openings but not less than
i) 3.5 m above the adjacent ground level,
ii) 1.5 m from any building opening, and
iii) 7.5 m from any dispenser, and
b) shall discharge so that flammable vapours will not enter building openings or be trapped near any part of the building.
2) Intent StatementVent pipe outlets from underground storage tanks for Class II or IIIA liquids shall be located outside buildings at a height that is above the fill pipe opening but not less than 2 m above finished ground level.
3) Intent StatementVent pipes from underground storage tanks for flammable liquids or combustible liquids shall not be obstructed by any device that may cause excessive back pressure, except that vent pipes from underground storage tanks for Class II or IIIA liquids are permitted to be fitted with return bends, coarse screens or other devices to minimize the entry of foreign material.
4) Intent StatementVent piping shall enter the storage tank through the top of the tank and shall not extend into the tank more than 25 mm.
5) Intent StatementVent piping shall be
a) installed so that any nominally horizontal run shall slope towards the storage tank,
b) constructed without traps,
c) adequately supported to prevent sagging, and
d) where necessary, protected against mechanical damage.
6) Intent Statementchange beginVent piping shall be tested for leaks at the commissioning stage in conformance with Clause 4.4.1.2.(1)(a).change end
4.3.11.4. Interconnection of Vent Pipes
1) Intent StatementExcept as permitted in Sentence (2), where vent piping connects 2 or more storage tanks, pipe sizes shall be designed to vent the combined vapours produced in the connected underground storage tanks without exceeding the allowable stresses of the tanks when being filled simultaneously.
2) Intent StatementWhere it is not possible to fill the connected storage tanks referred to in Sentence (1) simultaneously, or where the connected vents have a vapour recovery system, the vent piping shall be sized to accommodate the maximum vapour flow possible in the system.
3) Intent StatementVent piping for an underground storage tank containing a Class I liquid shall not be connected to the vent piping for a storage tank containing a Class II or IIIA liquid unless an effective method is provided to prevent the vapours from the Class I liquid storage tank from entering the other tank.

4.3.12. Openings Other than Vents in Underground Storage Tanks

4.3.12.1. Connections
1) Intent StatementConnections for all openings in underground storage tanks shall be liquid- and vapour-tight.
4.3.12.2. Openings for Measuring Liquid Level
1) Intent StatementOpenings for measuring liquid levels in underground storage tanks if independent of the fill pipe shall be equipped with a vapour-tight cap or cover which shall be opened only when measuring the liquid level.
4.3.12.3. Fill Piping and Discharge Piping
1) Intent StatementFill piping and discharge piping shall enter underground storage tanks only through the top of the tank and discharge piping used in suction systems shall be sloped toward the storage tanks.
2) Intent Statementchange beginThe fill point of an underground storage tank shall not be located higher than the discharge point of the tank’s vent.change end
3) Intent StatementExcept as provided in Sentence (5), connections used as part of normal operating conditions for filling or emptying storage tanks for flammable liquids and combustible liquids shall be located
a) outside buildings,
b) at a location free of sources of ignition, and
c) not less than 1.5 m away from building openings.
4) Intent StatementConnections for filling or emptying storage tanks described in Sentence (3) shall be kept closed to prevent leakage when not in use.
5) Intent StatementA filling connection described in Sentence (3) is permitted to be located inside a building if
a) this is made necessary
i) by a process or activity located indoors and to which the storage tank is directly associated, or
ii) for the collection of used liquids, and
b) the fill piping is provided with means to prevent flammable vapours from returning to the building.
6) Intent Statementchange beginIf a fill piping system has an offset component from the fill point on the storage tank, all fill pipes shall be
a) double-walled,
b) sloped to the storage tank, and
c) electronically monitored for leak detection in conformance with Section 4.4.
(See Appendix A.)
7) Intent StatementWhere the fill point is below the normal liquid level in the storage tank,
a) the fill line shall be equipped with a manual or automatic valve located at the fill point to prevent spillage when the fill cap is removed, and
b) if the storage tank contains flammable liquids or combustible liquids, the fill line drop tube shall be equipped with a method to prevent siphoning of the tank's content should a leak occur in the fill line.change end

4.3.13. Installation of Storage Tanks inside Buildings

4.3.13.1. Occupancy
1) Intent StatementExcept as provided in Article 4.3.13.2., storage tanks inside buildings shall
a) conform to Subsections 4.3.13. to 4.3.15.,
b) be permitted in industrial occupancies, and
c) change beginbe permitted in all occupancies where combustible liquids are stored and used as fuel for oil-burning equipment, emergency generators and fire pumps.change end
4.3.13.2. Stationary Combustion Engines
1) Intent StatementInstallations using Class I liquids as fuel supplies for stationary engines inside buildings shall conform to NFPA 37, “Installation and Use of Stationary Combustion Engines and Gas Turbines.”
4.3.13.3. Maximum Static Head
1) Intent StatementThe static head imposed on a storage tank inside a building shall not exceed 70 kPa (gauge) at the bottom of the tank when the vent or fill pipe is filled with liquid unless the tank is designed for greater pressures.
4.3.13.4. Maximum Quantities and Location
1) Intent StatementExcept as provided in Subsection 4.2.8. and in Sentence (2), storage tanks for flammable liquids or combustible liquids shall be
a) located in dedicated storage rooms conforming to Subsection 4.3.14., and
b) located in conformance with Tables 4.3.13.4.A change beginand 4.3.13.4.B (see Appendix A).change end
2) Intent StatementWhen quantities greater than those permitted for incidental use in Subsection 4.2.8. are required for special process operations, storage tanks for flammable liquids or combustible liquids are permitted to be located outside of a storage room referred to in Sentence (1), provided that
a) total quantities per fire compartment are not more than one-half the quantities permitted in Table 4.3.13.4.A,
b) they are located on the first storey, and
c) the installation conforms to Articles 4.3.13.9. to 4.3.13.12. and Article 4.3.14.4.
Table 4.3.13.4.A
Indoor Tank Storage change beginin Industrial Occupancieschange end
Forming part of Sentences 4.3.13.4.(1) and (2), and 4.3.13.8.(1)
Class of Liquid Storage Level

Maximum Quantity per Storage Room(1), L

One or More Tanks

Protected Storage(2)

 Unprotected Storage

Class I

First storey

 40 000 25 000

Storeys above the first storey

 7 500 Not Permitted

Basement

 Not Permitted Not Permitted

Classes II and IIIA

First storey

 200 000 100 000

Storeys above the first storey

 20 000 Not Permitted

Basement

 20 000 Not Permitted
Notes to Table 4.3.13.4.A:
(1) See Subsection 4.3.14.
(2) See Article 4.2.7.6.
Table 4.3.13.4.B
change beginIndoor Tank Storage in Occupancies Using Oil-Burning Equipment, Emergency Generators and Fire Pumps
Forming part of Sentences 4.3.13.4.(1) and 4.3.13.5.(1) and (2)
Class of Liquid Storage Level

Quantity per Protected Storage Room(1), L

Individual Tank

Aggregate

Classes II and IIIA

First storey

 > 2 500(2)(3) 200 000
> 20 000(2)(4)

Basement and storeys above the first storey

 > 2 500(3) 20 000
> 20 000(4) 45 000
Notes to Table 4.3.13.4.B:
(1) See Article 4.2.7.6.
(2) For industrial occupancies where the tanks are located in a separate storage room from the equipment, refer to Table 4.3.13.4.A.
(3) See Sentence 4.3.13.5.(1).
(4) See Sentence 4.3.13.5.(2).
4.3.13.5. Storage Tank Construction
1) Intent StatementStorage tanks with an individual capacity exceeding 2 500 L but not exceeding 20 000 L that are used in conformance with Table 4.3.13.4.B shall be
a) of double-walled construction in conformance with Clause 4.3.1.2.(1)(e) or a minimum of 300 deg. secondarily contained construction, and
b) monitored for leakage in conformance with Sentence 4.4.2.1.(7).
2) Intent StatementStorage tanks with an individual capacity exceeding 20 000 L that are used in conformance with Table 4.3.13.4.B shall
a) conform to Clause 4.3.1.2.(1)(l), and
b) be monitored for leakage in conformance with Sentence 4.4.2.1.(7).
4.3.13.6. Piping Systems
1) Intent StatementPiping systems serving oil-burning equipment, diesel-engine-driven emergency generators and fire pumps shall conform to CSA B139, “Installation Code for Oil-Burning Equipment.”change end
4.3.13.7. Fire Compartments
1) Intent StatementFire compartments regulated by this Subsection shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 2 h.
4.3.13.8. Mixed Storage
1) Intent StatementWhen 2 or more classes of liquids are stored in a single storage room referred to in Sentence 4.3.13.4.(1), the total quantity permitted for each class of liquid shall be calculated as follows:
where
qI= the actual quantity of Class I liquids present,
qII + IIIA= the actual quantity of Class II and IIIA liquids present,
QI= the maximum quantity of Class I liquids permitted in Table 4.3.13.4.A,
QII + IIIA= the maximum quantity of Class II and IIIA liquids permitted in Table 4.3.13.4.A.
4.3.13.9. Storage Tanks outside Storage Rooms
1) Intent StatementWhere storage tanks for flammable liquids or combustible liquids are located outside of storage rooms conforming to Subsection 4.3.14.,
a) provision shall be made to contain change begina spill equal to at leastchange end 100% of the volume of the largest storage tank, or to drain away spilled flammable liquids or combustible liquids, and
b) the area in which the storage tanks are located shall be ventilated (see Appendix A).
4.3.13.10. Vents
1) Intent StatementExcept as provided in Sentence (2), normal and emergency vents for storage tanks in buildings shall be provided in conformance with Subsections 4.3.4. and 4.3.5. (See Appendix A.)
2) Intent StatementThe use of weak roof-to-side shell seams, designed to rupture before the allowable design stress of the storage tank is reached, shall not be permitted as a means of emergency venting of storage tanks inside buildings.
4.3.13.11. Supports, Foundations and Anchorage
1) Intent StatementExcept as provided in Sentence (2), where storage tanks for flammable liquids or combustible liquids are installed inside buildings, the supports, foundations and anchorage for such storage tanks shall be in conformance with Subsection 4.3.3.
2) Intent StatementWhere a storage tank is suspended, rather than supported on a foundation, supports shall be designed and installed in conformance with good engineering practice. (See Appendix A.)
4.3.13.12. Bonding and Grounding
1) Intent StatementWhere storage tanks for flammable liquids or combustible liquids are installed inside buildings, tanks, piping and discharge equipment shall be bonded and grounded.

4.3.14. Rooms for Storage Tanks

4.3.14.1. Design and Construction
1) Intent StatementRooms for storage tanks inside buildings, referred to in Sentence 4.3.13.4.(1), shall be
a) separated from the rest of the building by a fire separation having a fire-resistance rating of at least 2 h,
b) designed to contain change begina spill equal to at leastchange end 100% of the volume of the largest storage tank, or to drain away spilled flammable liquids or combustible liquids,
c) made liquid-tight where the walls join the floor, and
d) used for no other purposes than the storage and handling of flammable liquids or combustible liquids.
4.3.14.2. Clearances
1) Intent StatementA minimum clear space of 550 mm shall be maintained between the walls of a room described in Article 4.3.14.1. and the sides of any storage tanks within the room.
4.3.14.3. Explosion Venting
1) Intent StatementWhere Class IA or IB liquids are dispensed within a storage room, the room shall be designed to prevent critical structural and mechanical damage from an internal explosion in conformance with NFPA 68, “Explosion Protection by Deflagration Venting.” (See A-3.2.8.2.(1)(d) in Appendix A.)
4.3.14.4. Hose Stations and Portable Extinguishers
1) In buildings not required to be equipped with a standpipe and hose system by the British Columbia Building Code, hose stations shall be provided in the vicinity of the storage room, such that all parts of the room are within reach of a hose stream. (See Appendix A.)

contentHistory

2) Intent StatementPortable extinguishers for Class B fires shall be provided.
4.3.14.5. Placards
1) Intent StatementPlacards conforming to Article 3.2.7.14., identifying the liquids stored as flammable liquids or combustible liquids and the capacities of the storage tanks, shall be posted in a conspicuous location outside of the room, and that information shall be included in the fire safety plan required in Article 4.1.5.5.

4.3.15. Openings Other than Vents in Storage Tanks inside Buildings

4.3.15.1. Connections
1) Intent StatementConnections for all openings in storage tanks in buildings shall be liquid- and vapour-tight.
2) Intent StatementConnections to storage tanks through which liquid can flow shall be provided with valves located as close as practicable to the tank.
4.3.15.2. Openings for Liquid Level Measurement
1) Intent StatementOpenings that are independent of the fill pipe and are used for measuring the liquid level in storage tanks containing Class I or II liquids shall be equipped with a vapour-tight cap which shall be opened only when measuring the liquid level.
2) Intent StatementOpenings referred to in Sentence (1) shall be protected against overflow and vapour pressure by means of a spring-loaded check valve.

4.3.16. Out of Service

4.3.16.1. Underground Storage Tanks
1) Intent StatementThe removal, abandonment in place, disposal or temporary taking out of service of an underground storage tank shall be in conformance with good engineering practice. (See Appendix A.)
4.3.16.2. Aboveground Storage Tanks
1) Intent StatementWhen an aboveground storage tank will be out of service or unsupervised for a period not exceeding 180 days, the piping from the tank shall be capped or the valves that are necessary to achieve similar isolation of the tank shall be closed and securely locked.
2) Intent StatementWhere a storage tank referred to in Sentence (1) contains flammable liquids or combustible liquids, the liquid level in the tank shall be measured and compared with subsequent readings taken at intervals not greater than one month.
3) Intent StatementWhen an aboveground storage tank will be out of service or unsupervised for a period exceeding 180 days, all liquid and vapours shall be removed from the storage tank and its connected piping.
4.3.16.3. Disposal
1) Intent StatementWhere a storage tank is to be permanently disposed of, sufficient openings shall be cut in the tank to render it unfit for further use.
4.3.16.4. change beginUnderground Piping Systems
1) Intent StatementThe removal, abandonment in place, disposal or temporary taking out of service of an underground piping system shall be in conformance with good engineering practice. (See A-4.3.16.1.(1) in Appendix A.)change end