NR 440.285(4)(a)1.1. Visually inspect the internal floating roof, the primary seal, and the secondary seal (if one is in service), prior to filling the storage vessel with VOL. If there are holes, tears or other openings in the primary seal, the secondary seal, or the seal fabric or defects in the internal floating roof, or both, the owner or operator shall repair the items before filling the storage vessel.
NR 440.285(4)(a)2.2. For vessels equipped with a liquid-mounted or mechanical shoe primary seal, visually inspect the internal floating roof and the primary seal or the secondary seal (if one is in service) through manholes and roof hatches on the fixed roof at least once every 12 months after initial fill. If the internal floating roof is not resting on the surface of the VOL inside the storage vessel, or there is liquid accumulated on the roof, or the seal is detached, or there are holes or tears in the seal fabric, the owner or operator shall repair the items or empty and remove the storage vessel from service within 45 days. If a failure that is detected during inspections required under this paragraph cannot be repaired within 45 days and if the vessel cannot be emptied within 45 days, a 30-day extension may be requested from the department in the inspection report required in sub. (6) (a) 3. A request for an extension shall document that alternate storage capacity is unavailable and specify a schedule of actions the company owner or operator shall take to assure that the control equipment will be repaired or the vessel will be emptied as soon as possible.
NR 440.285(4)(a)3.3. For vessels equipped with a double-seal system as specified in sub. (3) (a) 1. b. 2).
NR 440.285(4)(a)3.a.a. Visually inspect the vessel as specified in subd. 4. at least every 5 years; or
NR 440.285(4)(a)3.b.b. Visually inspect the vessel as specified in subd. 2.
NR 440.285(4)(a)4.4. Visually inspect the internal floating roof, the primary seal, the secondary seal (if one is in service), gaskets, slotted membranes (if any), and sleeve seals (if any) each time the storage vessel is emptied and degassed. If the internal floating roof has defects, the primary seal has holes, tears or other openings in the seal or the seal fabric, the secondary seal has holes, tears or other openings in the seal or the seal fabric, the gaskets no longer close off the liquid surfaces from the atmosphere, or the slotted membrane has more than 10% open area, the owner or operator shall repair the items as necessary so that none of the conditions specified in this paragraph exist before refilling the storage vessel with VOL. In no event may inspections conducted in accordance with this provision occur at intervals greater than 10 years in the case of vessels undergoing annual visual inspections as specified in subds. 2. and 3. b. nor at intervals greater than 5 years in the case of vessels specified in subd. 3. a.
NR 440.285(4)(a)5.5. Notify the department in writing at least 30 days prior to the filling or refilling of each storage vessel for which an inspection is required by subds. 1. and 4. to afford the department the opportunity to have an observer present. If the inspection required by subd. 4. is not planned and the owner or operator could not have known about the inspection 30 days in advance of refilling the storage vessel, the owner or operator shall notify the department at least 7 days prior to the refilling of the storage vessel. Notification shall be made by telephone immediately followed by written documentation demonstrating why the inspection was unplanned. Alternatively, this notification including the written documentation may be made in writing and sent by express mail so that it is received by the department at least 7 days prior to the refilling.
NR 440.285(4)(b)(b) After installing the control equipment required to meet sub. (3) (a) 2. (external floating roof), the owner or operator shall:
NR 440.285(4)(b)1.1. Determine the gap areas and maximum gap widths, between the primary seal and the wall of the storage vessel and between the secondary seal and the wall of the storage vessel according to the following frequency.
NR 440.285(4)(b)1.a.a. Measurements of gaps between the storage vessel wall and the primary seal (seal gaps) shall be performed during the hydrostatic testing of the vessel or within 60 days of the initial fill with VOL and at least once every 5 years thereafter.
NR 440.285(4)(b)1.b.b. Measurements of gaps between the storage vessel wall and the secondary seal shall be performed within 60 days of the initial fill with VOL and at least once per year thereafter.
NR 440.285(4)(b)1.c.c. If any source ceases to store VOL for a period of one year or more, subsequent introduction of VOL into the vessel shall be considered an initial fill for the purposes of subd. 1. a. and b.
NR 440.285(4)(b)2.2. Determine gap widths and areas in the primary and secondary seals individually by the following procedures:
NR 440.285(4)(b)2.a.a. Measure seal gaps, if any, at one or more floating roof levels when the roof is floating off the roof leg supports.
NR 440.285(4)(b)2.b.b. Measure seal gaps around the entire circumference of the storage vessel in each place where a 0.32-cm diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the storage vessel and measure the circumferential distance of each such location.
NR 440.285(4)(b)2.c.c. The total surface area of each gap described in subd. 2. b. shall be determined by using probes of various widths to measure accurately the actual distance from the storage vessel wall to the seal and multiplying each such width by its respective circumferential distance.
NR 440.285(4)(b)3.3. Add the gap surface area of each gap location for the primary seal and the secondary seal individually and divide the sum for each seal by the nominal diameter of the storage vessel and compare each ratio to the respective standards in subd. 4.
NR 440.285(4)(b)4.4. Make necessary repairs or empty the storage vessel within 45 days of identification in any inspection for seals not meeting the requirements listed in subd. 4. a.
NR 440.285(4)(b)4.a.a. The accumulated area of gaps between the storage vessel wall and the mechanical shoe or liquid-mounted primary seal may not exceed 212 cm2 per meter of storage vessel diameter, and the width of any portion of any gap may not exceed 3.81 cm.
1) One end of the mechanical shoe is to extend into the stored liquid, and the other end is to extend a minimum vertical distance of 61 cm above the stored liquid surface.
2) There may be no holes, tears, or other openings in the shoe, seal fabric, or seal envelope.
NR 440.285(4)(b)4.b.b. The secondary seal is to meet the following requirements:
1) The secondary seal is to be installed above the primary seal so that it completely covers the space between the roof edge and the storage vessel wall except as provided in subd. 2. c.
2) The accumulated area of gaps between the storage vessel wall and the secondary seal may not exceed 21.2 cm2 per meter of storage vessel diameter, and the width of any portion of any gap may not exceed 1.27 cm.
3) There may be no holes, tears, or other openings in the seal or seal fabric.
NR 440.285(4)(b)4.c.c. If a failure that is detected during inspections required in subd. 1 cannot be repaired within 45 days, a 30-day extension may be requested from the department in the inspection report required in sub. (6) (b) 4. An extension request shall include a demonstration of unavailability of alternate storage capacity and a specification of a schedule that will assure that the control equipment will be repaired or the vessel will be emptied as soon as possible.
NR 440.285(4)(b)5.5. Notify the department 30 days in advance of any gap measurements required by subd. 1. to afford the department opportunity to have an observer present.
NR 440.285(4)(b)6.6. Visually inspect the external floating roof, the primary seal, secondary seal, and fittings each time the vessel is emptied and degassed.
NR 440.285(4)(b)6.a.a. If the external floating roof has defects, or the primary seal has holes, tears, or other openings in the seal or the seal fabric, the owner or operator shall repair the items as necessary so that none of the conditions specified in this paragraph exist before filling or refilling the storage vessel with VOL.