SECTION 252:100-39-30. Petroleum liquid storage in vessels with external floating roofs

(a)   Definitions. The following words and terms, when used in this Section, shall have the following meaning, unless the context clearly indicates otherwise.

(1)   "Condensate" means hydrocarbon liquid separated from natural gas which condenses due to changes in the temperature and/or pressure and remains liquid at standard conditions.

(2)   "Drilling or production facility" means all drilling and servicing equipment, wells, flow lines, separators, equipment, gathering lines, and auxiliary non-transportation-related equipment used in the production of petroleum but does not include natural gasoline plants.

(3)   "External floating roof" means a storage vessel cover in an open top tank consisting of a double deck or pontoon single deck which rests upon and is supported by the petroleum liquid being contained and is equipped with a closure seal or seals to close the space between the roof edge and tank wall.

(4)   "Lease custody transfer" means the transfer of produced crude oil and/or condensate, after processing and/or treating in the producing operations, from storage vessels or automatic transfer facilities to pipelines or any other form of transportation.

(5)   "Liquid-mounted seal" means primary seal mounted in continuous contact with the liquid between the vessel wall and the floating roof.

(6)   "Petroleum liquid" means crude oil, condensate, and any finished or intermediate liquid products manufactured or extracted in a petroleum refinery.

(7)   "Vapor-mounted seal" means a primary seal mounted so there is an annular vapor space underneath the seal. The annular vapor space is bounded by the bottom of the primary seal, the vessel wall, the liquid surface, and the floating roof.

(8)   "Waxy, high pour point crude oil" means a crude oil with a pour point of 59^oF or higher as determined by the American Society of Testing and Materials Standard D97-66, "Test for Pour Point of Petroleum Oils."

(b)   Applicability.

(1)   This Section applies to petroleum liquid storage vessels equipped with external floating roofs, having capacities greater than 40,000 gal (150,000l).

(2)   This Section does not apply to petroleum liquid storage vessels that:

(A)   are used to store waxy, high pour point crude oil;

(B)   have capacities less than 422,675 gal ( 1,600 m) and are used to store produced crude oil and condensate prior to lease custody transfer;

(C)   contain a petroleum liquid with a true vapor pressure less than 1.5 psia (10.5 kPa);

(D)   contain a petroleum liquid with a true vapor pressure less than 4.0 psia (27.6 kPa) if the vessels are of welded construction and have a metallic-type shoe seal, a liquid-mounted foam seal, a liquid-mounted liquid filled type seal, or other closure device of demonstrated equivalence approved by the Division Director; or,

(E)   are of welded construction, are equipped with a metallic-type shoe primary seal and have a secondary seal from the top of the shoe seal to the vessel wall (shoe-mounted secondary seal).

(3)   Storage vessels that are subject to the equipment standards for external floating roofs in 40 CFR 60 Subparts Ka or Kb are exempt from the requirements of 252:100-39-30.

(4)   Storage vessels that are subject to the equipment standards for external floating roofs in 40 CFR 63 Subparts CC (63.646) or G shall be exempt from the requirements of 252:100-39-30 upon the date compliance with the standards in Subparts CC and G is required.

(c)   Equipment and operating requirements.

(1)   Standards. Each storage vessel used to store a petroleum liquid shall meet the following conditions.

(A)   The vessel has been fitted with:

(i)   a continuous secondary seal extending from the floating roof to the vessel wall (rim-mounted secondary seal); or,

(ii)   a closure device or other device which controls VOC emissions with an effectiveness equal to or greater than a seal required in 252:100-39-30(c)(1)(A)(i) and approved by the Division Director.

(B)   All seal closure devices meet the following requirements.

(i)   There are no visible holes, tears, or other openings in the seal(s) or seal fabric.

(ii)   The seal(s) are intact and uniformly in place around the circumference of the floating roof between the floating roof and the vessel wall.

(iii)   The accumulated area of gaps exceeding 1/8 in. (0.32 cm) in width between the secondary seal and the vessel wall when the secondary seal is used in combination with a vapor mounted primary seal shall not exceed 1.0 in./ft of vessel diameter (21.2 cm/m of vessel diameter). This shall be determined by physically measuring the length and width of all gaps around the entire circumference of the secondary seal in each place where a 1/8 in. (0.32 cm) uniform diameter probe passes freely between the seal and the vessel wall and summing the areas of the individual gaps.

(C)   All openings in the external floating roof, except for automatic bleeder vents, rim space vents, and leg sleeves, are:

(i)   equipped with covers, seals, or lids in the closed position except when the openings are in actual use; and,

(ii)   equipped with projections into the vessel which remain below the liquid surface at all times.

(D)   Automatic bleeder vents are closed at all times except when the roof is floated off or landed on the roof leg supports.

(E)   Rim vents are set to open when the roof is being floated off the leg supports or at the manufacturer's recommended settings.

(F)   Emergency roof drains are provided with slotted membrane fabric covers or equivalent covers which cover at least 90 percent of the area of the opening.

(2)   Monitoring. The owner or operator of a petroleum liquid storage vessel with an external floating roof subject to this Section shall:

(A)   perform routine inspections semi-annually in order to ensure compliance with 252:100-39-30(c)(1)(B)(i), i.e., no visible holes, tears, or other openings in the seals or seal fabric;

(B)   measure the secondary seal gap annually in accordance with 252:100-39-30(c)(1)(B)(iii), when the floating roof is equipped with a vapor-mounted primary seal; and,

(C)   maintain records of the types of volatile petroleum liquids stored, the true vapor pressure of the liquid as stored, and the results of the inspections performed in 252:100-39-30(c)(2)(A) and 252:100-39-30(c)(2)(B).

(3)   Recordkeeping.

(A)   Copies of all records under 252:100-39-30(c)(2) shall be retained by the owner or operator for a minimum of two years after the date on which the record was made.

(B)   Copies of all records under this Section shall be made available to the Division Director, upon request, at any reasonable time.

(d)   Compliance schedule. Compliance with this Section shall be accomplished by affected facilities by May 23, 1982.

[Source: Added at 11 Ok Reg 977, eff 1-14-94 (emergency); Added at 11 Ok Reg 2031, eff 5-26-94; Amended at 16 Ok Reg 1774, eff 6-11-99; Amended at 20 Ok Reg 1576, eff 6-12-03]