NR 665.1085(6)(a)3.a.a. Except for automatic bleeder vents (vacuum breaker vents) and rim space vents, each opening in a non-contact external floating roof shall project below the liquid surface. NR 665.1085(6)(a)3.b.b. Except for automatic bleeder vents, rim space vents, roof drains and leg sleeves, equip each opening in the roof with a gasketed cover, seal or lid. NR 665.1085(6)(a)3.c.c. Equip each access hatch and each gauge float well with a cover designed to be bolted or fastened when the cover is secured in the closed position. NR 665.1085(6)(a)3.e.e. Equip each roof drain that empties into the liquid managed in the tank with a slotted membrane fabric cover that covers at least 90 percent of the area of the opening. NR 665.1085(6)(a)3.f.f. Equip each unslotted and slotted guide pole well with a gasketed sliding cover or a flexible fabric sleeve seal. NR 665.1085(6)(a)3.h.h. Equip each slotted guide pole with a gasketed float or other device which closes off the liquid surface from the atmosphere. NR 665.1085(6)(b)(b) Operate the tank according to all of the following requirements: NR 665.1085(6)(b)1.1. When the floating roof is resting on the leg supports, the process of filling, emptying or refilling shall be continuous and shall be completed as soon as practical. NR 665.1085(6)(b)2.2. Except for automatic bleeder vents, rim space vents, roof drains and leg sleeves, secure and maintain each opening in the roof in a closed position at all times except when the closure device must be open for access. NR 665.1085(6)(b)3.3. Bolt or fasten covers on each access hatch and each gauge float well when secured in the closed position. NR 665.1085(6)(b)4.4. Set closed automatic bleeder vents at all times when the roof is floating, except when the roof is being floated off or is being landed on the leg supports. NR 665.1085(6)(b)5.5. Set to open rim space vents only at those times that the roof is being floated off the roof leg supports or when the pressure beneath the rim seal exceeds the manufacturer’s recommended setting. NR 665.1085(6)(b)6.6. Secure the cap on the end of each unslotted guide pole in the closed position at all times except when measuring the level of the liquid in the tank or collecting samples of the liquid. NR 665.1085(6)(b)7.7. Secure the cover on each gauge hatch or sample well in the closed position at all times except when the hatch or well must be opened for access. NR 665.1085(6)(b)8.8. Both the primary seal and the secondary seal shall completely cover the annular space between the external floating roof and the wall of the tank in a continuous fashion except during inspections. NR 665.1085(6)(c)(c) Inspect the external floating roof according to all of the following procedures: NR 665.1085(6)(c)1.1. Measure the external floating roof seal gaps according to all of the following requirements: NR 665.1085(6)(c)1.a.a. Perform measurements of gaps between the tank wall and the primary seal within 60 calendar days after initial operation of the tank following installation of the floating roof and, thereafter, at least once every 5 years. NR 665.1085(6)(c)1.b.b. Perform measurements of gaps between the tank wall and the secondary seal within 60 calendar days after initial operation of the tank following installation of the floating roof and, thereafter, at least once every year. NR 665.1085(6)(c)1.c.c. If a tank ceases to hold hazardous waste for a period of one year or more, subsequent introduction of hazardous waste into the tank is an initial operation for the purposes of subd. 1. a. and b. NR 665.1085(6)(c)1.d.d. Determine the total surface area of gaps in the primary seal and in the secondary seal individually using the following procedure: 1) Perform the seal gap measurements at one or more floating roof levels when the roof is floating off the roof supports.
2) Measure seal gaps, if any, around the entire perimeter of the floating roof in each place where a 0.32-centimeter (cm) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the tank and measure the circumferential distance of each location.
3) For a seal gap measured under this paragraph, determine the gap surface area using probes of various widths to measure accurately the actual distance from the tank wall to the seal and multiplying each width by its respective circumferential distance.
4) Calculate the total gap area by adding the gap surface areas determined for each identified gap location for the primary seal and the secondary seal individually, and then dividing the sum for each seal type by the nominal diameter of the tank. Then compare these total gap areas per unit of tank diameter for the primary seal and secondary seal to the respective standards for the seal type in par. (a) 2.
NR 665.1085(6)(c)1.e.e. In the event that the seal gap measurements do not conform to the specifications in par. (a) 2., repair the defect according to sub. (11).