§65.44. External floating roof (EFR). — Inbound Citations

(4) If an owner or operator installs an external floating roof and, at initial startup, chooses to comply with 40 CFR part 65, subpart C, a report shall be furnished to the Administrator stating that the control equipment meets the specifications of 40 CFR 65.44. This report shall be an attachment to the notification required by 40 CFR 65.5(b).

(2) Operate and maintain an external floating roof meeting the requirements of § 65.44.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

(c) An owner or operator who elects to comply with § 65.43, § 65.44, or § 65.45 shall submit, as applicable, the reports specified in paragraphs (c)(1) and (2) of this section except as specified in paragraph (c)(3) of this section. Each written notification or report shall also include the information specified in § 65.5(f).

(1) In order to afford the Administrator the opportunity to have an observer present, notify the Administrator prior to refilling of a storage vessel that has been emptied. If the storage vessel is equipped with an internal floating roof as specified in § 65.43, an external floating roof as specified in § 65.44, or an external floating roof converted to an internal floating roof as specified in § 65.45, the notification shall meet either of the following requirements, as applicable.

(i) Notify the Administrator in writing at least 30 calendar days prior to the refilling of each storage vessel; or

(ii) If the inspection is not planned and the owner or operator could not have known about the inspection 30 calendar days in advance of refilling the vessel, the owner or operator shall notify the Administrator as soon as practical, but no later than 7 calendar days prior to the refilling of the storage vessel. Notification may be made by telephone and immediately followed by written documentation demonstrating why the inspection was unplanned. Alternatively, the notification including the written documentation may be made in writing and sent so that it is received by the Administrator at least 7 calendar days prior to refilling.

(2) In order to afford the Administrator the opportunity to have an observer present during seal gap measurements, the owner or operator of a storage vessel equipped with an external floating roof as specified in § 65.44 shall meet either of the following notification requirements, as applicable:

(i) Notify the Administrator in writing at least 30 calendar days in advance of any seal gap measurements; or

(ii) If the seal gap measurements are not planned and the owner or operator could not have known about the seal gap measurements 30 calendar days in advance, the owner or operator shall notify the Administrator as soon as practical, but no later than 7 calendar days prior to the seal gap measurements. Notification may be made by telephone and immediately followed by written documentation demonstrating why the seal gap measurements were unplanned. Alternatively, the notification including the written documentation may be made in writing and sent so that it is received by the Administrator at least 7 calendar days prior to refilling.

(3) Where a notification required by paragraphs (c)(1) or (2) of this section is sent to a delegated State or local agency, a copy of the notification to the Administrator is not required. A delegated State or local agency may waive the requirements for these notifications.

(a) The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof shall comply with the design requirements listed in paragraphs (a)(1) through (3) of this section.

(1) The external floating roof shall be designed to float on the stored liquid surface except when the floating roof must be supported by the leg supports.

(2) The external floating roof shall be equipped with a closure device between the wall of the storage vessel and the roof edge.

(i) Except as provided in paragraph (a)(2)(iii) of this section, the closure device is to consist of two continuous seals, one above the other. The lower seal is referred to as the primary seal and the upper seal is referred to as the secondary seal.

(ii) Except as provided in paragraph (a)(2)(iv) of this section, the primary seal shall be either a metallic shoe seal or a liquid-mounted seal.

(iii) If the external floating roof is equipped with a liquid-mounted or metallic shoe primary seal as of December 31, 1992, the requirement for a secondary seal in paragraph (a)(2)(i) of this section does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

(iv) If the external floating roof is equipped with a vapor-mounted primary seal and a secondary seal as of December 31, 1992, the requirement for a liquid-mounted or metallic shoe primary seal in paragraph (a)(2)(ii) of this section does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

(3) The external floating roof shall meet the following specifications:

(i) Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in the noncontact external floating roof shall provide a projection below the stored liquid surface except as provided in paragraph (a)(3)(xiii) of this section.

(ii) Covers on each access hatch and each gauge float well shall be designed to be bolted or fastened when they are closed.

(iii) Except for automatic bleeder vents, rim space vents, roof drains, and leg sleeves, each opening shall be equipped with a gasketed cover, seal, or lid.

(iv) Automatic bleeder vents and rim space vents shall be equipped with a gasket.

(v) Each roof drain that empties into the stored liquid shall be equipped with a slotted membrane fabric cover that covers at least 90 percent of the area of the opening.

(vi) Each unslotted and slotted guide pole well shall be equipped with a gasketed sliding cover or a flexible fabric sleeve seal.

(vii) Except for antirotational devices equipped with a welded cap, each unslotted guide pole shall be equipped with a gasketed cap on the end of the pole.

(viii) Each slotted guide pole shall be equipped with a gasketed float or other device that closes off the stored liquid surface from the atmosphere.

(ix) Each gauge hatch/sample well shall be equipped with a gasketed cover.

(x) Where a metallic shoe seal is in use as the primary seal, one end of the metallic shoe shall be designed to extend into the stored liquid and the other end shall extend a minimum vertical distance of 61 centimeters (24 inches) above the stored liquid surface.

(xi) The secondary seal shall be designed to be installed above the primary seal so that it completely covers the space between the roof edge and the vessel wall.

(xii) For the primary and secondary seals, there shall be no holes, tears, or other openings in the shoe, seal fabric, or seal envelope.

(xiii) If each opening in a noncontact external floating roof except for automatic bleeder vents (vacuum breaker vents) and rim space vents does not provide a projection below the liquid surface as of December 31, 1992, the requirement for providing these projections below the liquid surface does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

(a) The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof shall comply with the design requirements listed in paragraphs (a)(1) through (3) of this section.

(1) The external floating roof shall be designed to float on the stored liquid surface except when the floating roof must be supported by the leg supports.

(2) The external floating roof shall be equipped with a closure device between the wall of the storage vessel and the roof edge.

(i) Except as provided in paragraph (a)(2)(iii) of this section, the closure device is to consist of two continuous seals, one above the other. The lower seal is referred to as the primary seal and the upper seal is referred to as the secondary seal.

(ii) Except as provided in paragraph (a)(2)(iv) of this section, the primary seal shall be either a metallic shoe seal or a liquid-mounted seal.

(iii) If the external floating roof is equipped with a liquid-mounted or metallic shoe primary seal as of December 31, 1992, the requirement for a secondary seal in paragraph (a)(2)(i) of this section does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

(iv) If the external floating roof is equipped with a vapor-mounted primary seal and a secondary seal as of December 31, 1992, the requirement for a liquid-mounted or metallic shoe primary seal in paragraph (a)(2)(ii) of this section does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

(3) The external floating roof shall meet the following specifications:

(i) Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in the noncontact external floating roof shall provide a projection below the stored liquid surface except as provided in paragraph (a)(3)(xiii) of this section.

(ii) Covers on each access hatch and each gauge float well shall be designed to be bolted or fastened when they are closed.

(iii) Except for automatic bleeder vents, rim space vents, roof drains, and leg sleeves, each opening shall be equipped with a gasketed cover, seal, or lid.

(iv) Automatic bleeder vents and rim space vents shall be equipped with a gasket.

(v) Each roof drain that empties into the stored liquid shall be equipped with a slotted membrane fabric cover that covers at least 90 percent of the area of the opening.

(vi) Each unslotted and slotted guide pole well shall be equipped with a gasketed sliding cover or a flexible fabric sleeve seal.

(vii) Except for antirotational devices equipped with a welded cap, each unslotted guide pole shall be equipped with a gasketed cap on the end of the pole.

(viii) Each slotted guide pole shall be equipped with a gasketed float or other device that closes off the stored liquid surface from the atmosphere.

(ix) Each gauge hatch/sample well shall be equipped with a gasketed cover.

(x) Where a metallic shoe seal is in use as the primary seal, one end of the metallic shoe shall be designed to extend into the stored liquid and the other end shall extend a minimum vertical distance of 61 centimeters (24 inches) above the stored liquid surface.

(xi) The secondary seal shall be designed to be installed above the primary seal so that it completely covers the space between the roof edge and the vessel wall.

(xii) For the primary and secondary seals, there shall be no holes, tears, or other openings in the shoe, seal fabric, or seal envelope.

(xiii) If each opening in a noncontact external floating roof except for automatic bleeder vents (vacuum breaker vents) and rim space vents does not provide a projection below the liquid surface as of December 31, 1992, the requirement for providing these projections below the liquid surface does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

(a) The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof shall comply with the design requirements listed in paragraphs (a)(1) through (3) of this section.

(1) The external floating roof shall be designed to float on the stored liquid surface except when the floating roof must be supported by the leg supports.

(2) The external floating roof shall be equipped with a closure device between the wall of the storage vessel and the roof edge.

(i) Except as provided in paragraph (a)(2)(iii) of this section, the closure device is to consist of two continuous seals, one above the other. The lower seal is referred to as the primary seal and the upper seal is referred to as the secondary seal.

(ii) Except as provided in paragraph (a)(2)(iv) of this section, the primary seal shall be either a metallic shoe seal or a liquid-mounted seal.

(iii) If the external floating roof is equipped with a liquid-mounted or metallic shoe primary seal as of December 31, 1992, the requirement for a secondary seal in paragraph (a)(2)(i) of this section does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

(iv) If the external floating roof is equipped with a vapor-mounted primary seal and a secondary seal as of December 31, 1992, the requirement for a liquid-mounted or metallic shoe primary seal in paragraph (a)(2)(ii) of this section does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

(3) The external floating roof shall meet the following specifications:

(i) Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in the noncontact external floating roof shall provide a projection below the stored liquid surface except as provided in paragraph (a)(3)(xiii) of this section.

(ii) Covers on each access hatch and each gauge float well shall be designed to be bolted or fastened when they are closed.

(iii) Except for automatic bleeder vents, rim space vents, roof drains, and leg sleeves, each opening shall be equipped with a gasketed cover, seal, or lid.

(iv) Automatic bleeder vents and rim space vents shall be equipped with a gasket.

(v) Each roof drain that empties into the stored liquid shall be equipped with a slotted membrane fabric cover that covers at least 90 percent of the area of the opening.

(vi) Each unslotted and slotted guide pole well shall be equipped with a gasketed sliding cover or a flexible fabric sleeve seal.

(vii) Except for antirotational devices equipped with a welded cap, each unslotted guide pole shall be equipped with a gasketed cap on the end of the pole.

(viii) Each slotted guide pole shall be equipped with a gasketed float or other device that closes off the stored liquid surface from the atmosphere.

(ix) Each gauge hatch/sample well shall be equipped with a gasketed cover.

(x) Where a metallic shoe seal is in use as the primary seal, one end of the metallic shoe shall be designed to extend into the stored liquid and the other end shall extend a minimum vertical distance of 61 centimeters (24 inches) above the stored liquid surface.

(xi) The secondary seal shall be designed to be installed above the primary seal so that it completely covers the space between the roof edge and the vessel wall.

(xii) For the primary and secondary seals, there shall be no holes, tears, or other openings in the shoe, seal fabric, or seal envelope.

(xiii) If each opening in a noncontact external floating roof except for automatic bleeder vents (vacuum breaker vents) and rim space vents does not provide a projection below the liquid surface as of December 31, 1992, the requirement for providing these projections below the liquid surface does not apply until the next time the storage vessel is emptied and degassed, or by April 22, 2004, whichever occurs first.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

(d) For sources subject to the compliance certification provisions of title V, a recertification of continuous compliance with §§ 65.43(b)(1) and 65.44(b)(1) shall be based on the annual inspections required by § 65.43(c)(1)(i) and (c)(2)(ii)(A) and any observations made at other times when the roof is viewed.

(e) The owner or operator shall maintain a record for each storage vessel subject to §§ 65.43(b)(2) and 65.44(b)(2) identifying the date when the floating roof was set on its legs and the date when the roof was refloated. The record shall also indicate whether this was a continuous operation.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

The owner or operator who elects to control storage vessel regulated material emissions by using an external floating roof converted into an internal floating roof shall comply with the internal floating roof requirements of § 65.43 except § 65.43(a)(3), (b)(2), and (b)(3) and the external floating roof deck fitting requirements of § 65.44 except § 65.44(a)(1), (a)(2), (b)(1), (b)(8), (b)(9), (c), and (d), including the recordkeeping and reporting provisions referenced therein.

(1) Report the following information for each inspection conducted in accordance with § 65.43(c) and 65.44(c) in which an IFR or EFR failure is detected in the control equipment:

(i) If an IFR type A failure or an EFR failure is observed for vessels for which inspections are required under § 65.43(c)(1)(i), § 65.43(c)(2)(ii)(A), or § 65.44(c)(10), each report shall include the inspection results record listed in § 65.47(c)(1)(ii). If an extension is utilized in accordance with § 65.43(d)(1) or § 65.44(d)(1), the report shall include the records listed in § 65.47(c)(1)(ii) plus the documentation specified in § 65.47(d)(1).

(ii) If an IFR type B failure is observed for vessels for which inspections are required under § 65.43(c)(1)(ii), (c)(2)(i), or (c)(2)(ii)(B), each report shall include a copy of the records listed in § 65.47(c)(1)(ii).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(2) For each EFR seal gap measurement required by § 65.44(c)(1), (2), or (3), a record describing the results of the measurement. The record shall identify the vessel on which the measurement was performed, shall include the date of the measurement, the raw data obtained in the measurement, and the calculations described in § 65.44(c)(7) and (8), and shall meet the following two additional requirements, as appropriate:

(i) In the event that the seal gap measurements do conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall submit the information specified in § 65.48(b)(2)(i) in the periodic report.

(ii) In the event that the seal gap measurements do not conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall also keep a description of the repairs that were made, the date the repairs were made, and the date the storage vessel was emptied and shall include a report of the seal gap measurement results in the periodic report as specified in § 65.48(b)(2)(ii).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(2) For each EFR seal gap measurement required by § 65.44(c)(1), (2), or (3), a record describing the results of the measurement. The record shall identify the vessel on which the measurement was performed, shall include the date of the measurement, the raw data obtained in the measurement, and the calculations described in § 65.44(c)(7) and (8), and shall meet the following two additional requirements, as appropriate:

(i) In the event that the seal gap measurements do conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall submit the information specified in § 65.48(b)(2)(i) in the periodic report.

(ii) In the event that the seal gap measurements do not conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall also keep a description of the repairs that were made, the date the repairs were made, and the date the storage vessel was emptied and shall include a report of the seal gap measurement results in the periodic report as specified in § 65.48(b)(2)(ii).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(2) For each EFR seal gap measurement required by § 65.44(c)(1), (2), or (3), a record describing the results of the measurement. The record shall identify the vessel on which the measurement was performed, shall include the date of the measurement, the raw data obtained in the measurement, and the calculations described in § 65.44(c)(7) and (8), and shall meet the following two additional requirements, as appropriate:

(i) In the event that the seal gap measurements do conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall submit the information specified in § 65.48(b)(2)(i) in the periodic report.

(ii) In the event that the seal gap measurements do not conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall also keep a description of the repairs that were made, the date the repairs were made, and the date the storage vessel was emptied and shall include a report of the seal gap measurement results in the periodic report as specified in § 65.48(b)(2)(ii).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(2) For each EFR seal gap measurement required by § 65.44(c)(1), (2), or (3), a record describing the results of the measurement. The record shall identify the vessel on which the measurement was performed, shall include the date of the measurement, the raw data obtained in the measurement, and the calculations described in § 65.44(c)(7) and (8), and shall meet the following two additional requirements, as appropriate:

(i) In the event that the seal gap measurements do conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall submit the information specified in § 65.48(b)(2)(i) in the periodic report.

(ii) In the event that the seal gap measurements do not conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall also keep a description of the repairs that were made, the date the repairs were made, and the date the storage vessel was emptied and shall include a report of the seal gap measurement results in the periodic report as specified in § 65.48(b)(2)(ii).

(i) For each vessel whose seal gaps are measured during the reporting period, identify each seal gap measurement made in accordance with § 65.44(c) in which the requirements of § 65.44(c)(7) or (8) are met.

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(2) For each EFR seal gap measurement required by § 65.44(c)(1), (2), or (3), a record describing the results of the measurement. The record shall identify the vessel on which the measurement was performed, shall include the date of the measurement, the raw data obtained in the measurement, and the calculations described in § 65.44(c)(7) and (8), and shall meet the following two additional requirements, as appropriate:

(i) In the event that the seal gap measurements do conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall submit the information specified in § 65.48(b)(2)(i) in the periodic report.

(ii) In the event that the seal gap measurements do not conform to the specifications in § 65.44(c)(7) and (8), the owner or operator shall also keep a description of the repairs that were made, the date the repairs were made, and the date the storage vessel was emptied and shall include a report of the seal gap measurement results in the periodic report as specified in § 65.48(b)(2)(ii).

(i) For each vessel whose seal gaps are measured during the reporting period, identify each seal gap measurement made in accordance with § 65.44(c) in which the requirements of § 65.44(c)(7) or (8) are met.

(c) To demonstrate compliance for an external floating roof vessel, the owner or operator shall use the procedures in paragraphs (c)(4) through (9) of this section for seal gaps according to the frequency specified in paragraphs (c)(1) through (3) of this section and meet the requirements of paragraph (c)(10) of this section.

(1) Measurements of gaps between the vessel wall and the primary seal shall be performed no less frequently than once every 5 years and at the times specified in paragraphs (c)(1)(i) and (ii) of this section. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(i) During the hydrostatic testing of the vessel, by initial startup, or within 90 days of the initial fill with regulated material.

(ii) For an external floating roof vessel equipped with a liquid-mounted or metallic shoe primary seal and without a secondary seal as provided for in paragraph (a)(2)(iii) of this section, measurements of gaps between the vessel wall and the primary seal shall be performed at least once per year until a secondary seal is installed. When a secondary seal is installed above the primary seal, measurements of gaps between the vessel wall and both the primary and secondary seals shall be performed within 90 calendar days of installation of the secondary seal and according to the frequency specified in paragraphs (c)(1) through (3) of this section thereafter.

(2) Measurements of gaps between the vessel wall and the secondary seal shall be performed no less frequently than once per year and within 90 days of the initial fill with regulated material, within 90 days of installation of the secondary seal, or by initial startup. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(3) If any storage vessel ceases to store regulated material for a period of 1 year or more, measurements of gaps between the vessel wall and the primary seal, and gaps between the vessel wall and the secondary seal shall be performed within 90 days of the vessel being refilled with regulated material. The owner or operator shall maintain records of the EFR seal gap measurements as specified in § 65.47(c)(2).

(4) If the tank contains regulated material, all primary seal inspections or gap measurements that require the removal or dislodging of the secondary seal shall be accomplished as soon as possible, and the secondary seal shall be replaced as soon as possible.

(5) The owner or operator shall notify the Administrator 30 days before any EFR seal gap measurement as specified in § 65.48(c)(2).

(6) Except as provided in paragraph (d) of this section, the owner or operator shall determine gap widths and gap areas in the primary and secondary seals (seal gaps) individually by the following procedures:

(i) Seal gaps, if any, shall be measured at one or more floating roof levels when the roof is not resting on the roof leg supports.

(ii) Seal gaps, if any, shall be measured around the entire circumference of the vessel in each place where a 0.32 centimeter ( 1/8 inch) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel. The circumferential distance of each such location shall also be measured.

(iii) The total surface area of each gap described in paragraph (c)(6)(ii) of this section shall be determined by using probes of various widths to measure accurately the actual distance from the vessel wall to the seal and multiplying each such width by its respective circumferential distance.

(7) The owner or operator shall add the gap surface area of each gap location for the primary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). For metallic shoe primary seals or liquid-mounted primary seals, the accumulated area of gaps between the vessel wall and the primary seal shall not exceed 212 square centimeters per meter of vessel diameter (10.0 square inches per foot of vessel diameter) and the width of any portion of any gap shall not exceed 3.81 centimeters (1.50 inches).

(8) The owner or operator shall add the gap surface area of each gap location for the secondary seal and divide the sum by the nominal diameter of the vessel. The owner or operator shall include the calculations in the record of the seal gap measurement as specified in § 65.47(c)(2). The accumulated area of gaps between the vessel wall and the secondary seal used in combination with a metallic shoe seal or liquid-mounted primary seal shall not exceed 21.2 square centimeters per meter of vessel diameter (1.00 square inch per foot of vessel diameter) and the width of any portion of any gap shall not exceed 1.27 centimeters (0.50 inch). The secondary seal gap requirements may be exceeded during the measurement of primary seal gaps as required by paragraph (c)(1) of this section.

(9) If the owner or operator determines that it is unsafe to perform the seal gap measurements or to inspect the vessel to determine compliance because the floating roof appears to be structurally unsound and poses an imminent or potential danger to inspecting personnel, the owner or operator shall comply with one of the following requirements:

(i) The owner or operator shall measure the seal gaps or inspect the storage vessel no later than 30 calendar days after the determination that the roof is unsafe; or

(ii) The owner or operator shall empty and remove the storage vessel from service no later than 45 calendar days after determining that the roof is unsafe. If the vessel cannot be emptied within 45 calendar days, the owner or operator may utilize up to two extensions of up to 30 additional calendar days each and comply with the recordkeeping requirements in § 65.47(d).

(10) The owner or operator shall visually inspect for EFR failures, the external floating roof, the primary seal, secondary seal, and fittings prior to initial filling and each time the vessel is emptied (including initially before the vessel is filled with regulated material), shall maintain records of the EFR inspection results as specified in § 65.47(c)(1), and shall comply with the refilling notification requirements specified in § 65.48(c)(1).

(2) For an extension pursuant to § 65.44(c)(9), an explanation of why it was unsafe to perform the inspection or seal gap measurement, documentation that alternate storage capacity is unavailable, and a schedule of actions that will ensure that the vessel will be emptied as soon as practical. As specified in § 65.48(b)(3), the owner or operator shall include this information in the periodic report.

(3) If an extension is utilized in accordance with § 65.44(c)(9), the owner or operator shall include the documentation specified in § 65.47(d)(2) in the next report required by § 65.5(e).

(1) For each IFR or EFR inspection required by § 65.43(c)(1) and (2), or § 65.44(c)(10), respectively, a record containing the following information, as appropriate:

(i) In the event that no IFR type A failure, IFR type B failure, or EFR failure is observed, a record showing that the inspection was performed. The record shall identify the storage vessel on which the inspection was performed, the date the storage vessel was inspected, and references indicating which items were inspected.

(ii) In the event that an IFR type A failure, IFR type B failure, or EFR failure is observed, a record that identifies the storage vessel on which the inspection was performed, the date the storage vessel was inspected, a description of the failure and of the repair made, the date the vessel was emptied (if applicable), and the date that the repair was made. As specified in § 65.48(b)(1), the owner or operator shall include this record in the periodic report.

(i) If an IFR type A failure or an EFR failure is observed for vessels for which inspections are required under § 65.43(c)(1)(i), § 65.43(c)(2)(ii)(A), or § 65.44(c)(10), each report shall include the inspection results record listed in § 65.47(c)(1)(ii). If an extension is utilized in accordance with § 65.43(d)(1) or § 65.44(d)(1), the report shall include the records listed in § 65.47(c)(1)(ii) plus the documentation specified in § 65.47(d)(1).

(1) For an extension pursuant to § 65.43(d)(1) or § 65.44(d)(1), a description of the failure, documentation that alternative storage capacity is unavailable, and a schedule of actions that will ensure that the control equipment will be repaired or the vessel will be emptied as soon as practical. As specified in § 65.48(b)(1)(i), the owner or operator shall include this information in the periodic report.

(i) If an IFR type A failure or an EFR failure is observed for vessels for which inspections are required under § 65.43(c)(1)(i), § 65.43(c)(2)(ii)(A), or § 65.44(c)(10), each report shall include the inspection results record listed in § 65.47(c)(1)(ii). If an extension is utilized in accordance with § 65.43(d)(1) or § 65.44(d)(1), the report shall include the records listed in § 65.47(c)(1)(ii) plus the documentation specified in § 65.47(d)(1).