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Oklahoma Administrative Code (Last Updated: March 11, 2021) |
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TITLE 165. Corporation Commission |
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Chapter 26. Aboveground Storage Tanks |
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Subchapter 2. General Requirements for Aboveground Storage Tank Systems |
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Part 1. DESIGN AND INSTALLATION |
SECTION 165:26-2-6. Vent piping requirements
Latest version.
- (a) For installations after October 13, 2018, each tank and each compartment of a compartment tank shall have both normal and emergency venting. The vent opening shall be in addition to the fill, withdrawal, and liquid level gauge opening.(b) Normal vents must be sized in accordance with either:(1) UL new tank manufacturing standards(2) API new tank manufacturing standards(3) API 2000, Venting Atmospheric and Low-Pressure Storage Tanks, or(4) Other accepted standards; or(5) Must be at least as large as the filling or withdrawal connection, whichever is larger, but in no case less than 1 1/4 in. (7 centimeters) nominal inside diameter.(c) Emergency vents must be sized in accordance with either:(1) UL new manufacturing standards(2) API new tank manufacturing standards(3) API 2000, Venting Atmospheric and Low-Pressure Storage Tanks, or(4) Appendix I, or(5) Other accepted standards.(d) Where vent pipe outlets for tanks storing Class I liquids are adjacent to buildings or public ways, they must be located so that the vapors are released at a safe point outside of buildings and not less than 12 ft. (3.6 meters) above the adjacent ground level.(e) In order to aid in dispersion, vapors must be discharged upward. Vent outlets must be located so that flammable vapors will not be trapped by eaves or other obstructions and be at least 5 ft. (1.5 meters) from building openings.(f) Vent pipes that are provided for normal tank venting must extend at least 12 ft. (3.6 meters) above ground level or 5 ft. above the roof line at the highest point of attachment.(g) Total venting capacity must be sized in accordance with:(1) UL new manufacturing standards(2) API new manufacturing standards(3) Wetted area calculations per tank design, and(4) Appendix I, or(5) Other approved method.