3) There may be no holes, tears or other openings in the seal or seal fabric.
4) The owner or operator is exempted from the requirements for secondary seals and the secondary seal gap criteria when performing gap measurements or inspections of the primary seal.
NR 440.28(3)(a)1.c.c. Each opening in the roof except for automatic bleeder vents and rim space vents shall provide a projection below the liquid surface. Each opening in the roof except for automatic bleeder vents, rim space vents and leg sleeves shall be equipped with a cover, seal or lid which shall be maintained in a closed position at all times (i.e., no visible gap) except when the device is in actual use or as described in subd. 1. d. Automatic bleeder vents shall be closed at all times when the roof is being floated off or is being landed on the roof leg supports. Rim vents shall be set to open when the roof is being floated off the roof legs supports or at the manufacturer’s recommended setting.
NR 440.28(3)(a)1.d.d. Each emergency roof drain shall be provided with a slotted membrane fabric cover that covers at least 90% of the area of the opening.
NR 440.28(3)(a)2.2. A fixed roof with an internal floating type cover equipped with a continuous closure device between the tank wall and the cover edge. The cover shall be floating at all times (i.e., off the leg supports), except during initial fill and when the tank is completely emptied and subsequently refilled. The process of emptying and refilling when the cover is resting on the leg supports shall be continuous and shall be accomplished as rapidly as possible. Each opening in the cover except for automatic bleeder vents and the rim space vents shall provide a projection below the liquid surface. Each opening in the cover except for automatic bleeder vents, rim space vents, stub drains and leg sleeves shall be equipped with a cover, seal or lid which shall be maintained in a closed position at all times (i.e., no visible gap) except when the device is in actual use. Automatic bleeder vents shall be closed at all times when the cover is floating except when the cover is being floated off or is being landed on the leg supports. Rim vents shall be set to open only when the cover is being floated off the leg supports or at the manufacturer’s recommended setting.
NR 440.28(3)(a)3.3. A vapor recovery system which collects all VOC vapors and gases discharged from the storage vessel, and a vapor return or disposal system which is designed to process such VOC vapors and gases so as to reduce their emission to the atmosphere by at least 95% by weight.
NR 440.28(3)(a)4.4. A system equivalent to those described in subd. 1., 2. or 3. as provided in sub. (5).
NR 440.28(3)(b)(b) The owner or operator of each storage vessel to which this section applies which contains a petroleum liquid which, as stored, has a true vapor pressure greater than 76.6 kPa (11.1 psia), shall equip the storage vessel with a vapor recovery system which collects all VOC vapors and gases discharged from the storage vessel, and a vapor return or disposal system which is designed to process such VOC vapors and gases so as to reduce their emission to the atmosphere by at least 95% by weight.
NR 440.28(4)(4)Testing and procedures.
NR 440.28(4)(a)(a) Except as provided in s. NR 440.08 (2), compliance with the standard prescribed in sub. (3) shall be determined as follows or in accordance with an equivalent procedure as provided in sub. (5).
NR 440.28(4)(a)1.1. The owner or operator of each storage vessel to which this section applies which has an external floating roof shall meet the following requirements:
NR 440.28(4)(a)1.a.a. Determine the gap areas and maximum gap widths between the primary seal and the storage vessel wall, and between the secondary seal and the storage vessel wall according to the following frequency:
1) For primary seals, gap measurements shall be performed within 60 days of the initial fill with petroleum liquid and at least once every 5 years thereafter. All primary seal inspections or gap measurements which require the removal or dislodging of the secondary seal shall be accomplished as rapidly as possible and the secondary seal shall be replaced as soon as possible.
2) For secondary seals, gap measurements shall be performed within 60 days of the initial fill with petroleum liquid and at least once every year thereafter.
3) If any storage vessel is out of service for a period of one year or more, subsequent refilling with petroleum liquid shall be considered initial fill for the purposes of subd. 1. a. 1) and 2).
4) Keep records of each gap measurement at the plant for a period of at least 2 years following the date of measurement. Each record shall identify the vessel on which the measurement was performed and shall contain the date of the seal gap measurement, the raw data obtained in the measurement process required by subd. 1. b. and the calculation required by subd. 1. c.
5) If either the seal gap calculated in accord with subd. 1. c. or the measured maximum seal gap exceeds the limitations specified by sub. (3), a report shall be furnished to the department within 60 days of the date of the measurement. The report shall identify the vessel and list each reason why the vessel did not meet the specifications of sub. (3). the report shall also describe the actions necessary to bring the storage vessel into compliance with the specifications of sub. (3).
NR 440.28(4)(a)1.b.b. Determine gap widths in the primary and secondary seals individually by the following procedures:
1) Measure seal gaps, if any, at one or more floating roof levels when the roof is floating off the roof leg supports.
2) Measure seal gaps around the entire circumference of the tank in each place where a 1/8 diameter uniform probe passes freely (without forcing or binding against seal) between the seal and the tank wall and measure the circumferential distance of each such location.
3) The total surface area of each gap described in subd. 1. b. 2) shall be determined by using probes of various widths to accurately measure the actual distance from the tank wall to the seal and multiplying each such width by its respective circumferential distance.
NR 440.28(4)(a)1.c.c. Add the gap surface area of each gap location for the primary seal and the secondary seal individually. Divide the sum for each seal by the nominal diameter of the tank and compare each ratio to the appropriate ratio in the standard in sub. (3) (a) 1. a. and b.
NR 440.28(4)(a)1.d.d. Provide the department 30 days prior notice of the gap measurement to afford it the opportunity to have an observer present.
NR 440.28(4)(a)2.2. The owner or operator of each storage vessel to which this section applies which has a vapor recovery and return or disposal system shall provide the following information to the department on or before the date on which construction of the storage vessel commences:
NR 440.28(4)(a)2.a.a. Emission data, if available, for a similar vapor recovery and return or disposal system used on the same type of storage vessel, which can be used to determine the efficiency of the system. A complete description of the emission measurement method used shall be included.
NR 440.28(4)(a)2.b.b. The manufacturer’s design specifications and estimated emission reduction capability of the system.
NR 440.28(4)(a)2.c.c. The operation and maintenance plan for the system.
NR 440.28(4)(a)2.d.d. Any other information which will be useful to the department in evaluating the effectiveness of the system in reducing VOC emissions.
NR 440.28(5)(5)Alternative means of emission limitation.