3) A mechanical shoe seal. A mechanical shoe seal is a metal sheet held vertically against the wall of the storage vessel by springs or weighted levers and is connected by braces to the floating roof. A flexible coated fabric (envelope) spans the annular space between the metal sheet and the floating roof.
NR 440.285(3)(a)1.c.
c. Each opening in a noncontact internal floating roof except for automatic bleeder vents (vacuum break vents) and the rim space vents is to provide a projection below the liquid surface.
NR 440.285(3)(a)1.d.
d. Each opening in the internal floating roof except for leg sleeves, automatic bleeder vents, rim space vents, column wells, ladder wells, sample wells and stub drains is to be equipped with a cover or lid which is to be maintained in a closed position at all times (i.e., no visible gap) except when the device is in actual use. The cover or lid shall be equipped with a gasket. Covers on each access hatch and automatic gauge float well shall be bolted except when they are in use.
NR 440.285(3)(a)1.e.
e. Automatic bleeder vents shall be equipped with a gasket and are to be closed at all times when the roof is floating except when the roof is being floated off or is being landed on the roof leg supports.
NR 440.285(3)(a)1.f.
f. Rim space vents shall be equipped with a gasket and are to be set to open only when the internal floating roof is not floating or at the manufacturer's recommended setting.
NR 440.285(3)(a)1.g.
g. Each penetration of the internal floating roof for the purpose of sampling shall be a sample well. The sample well shall have a slit fabric cover that covers at least 90% of the opening.
NR 440.285(3)(a)1.h.
h. Each penetration of the internal floating roof that allows for passage of a column supporting the fixed roof shall have a flexible fabric sleeve seal or a gasketed sliding cover.
NR 440.285(3)(a)1.i.
i. Each penetration of the internal floating roof that allows for passage of a ladder shall have a gasketed sliding cover.
NR 440.285(3)(a)2.
2. An external floating roof. An external floating roof means a pontoon-type or double-deck type cover that rests on the liquid surface in a vessel with no fixed roof. Each external floating roof shall meet the following specifications:
NR 440.285(3)(a)2.a.
a. Each external floating roof shall be equipped with a closure device between the wall of the storage vessel and the roof edge. The closure device is to consist of 2 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.
1) The primary seal shall be either a mechanical shoe seal or a liquid-mounted seal. Except as provided in sub. (4) (b) 4., the seal shall completely cover the annular space between the edge of the floating roof and storage vessel wall.
2) The secondary seal shall completely cover the annular space between the external floating roof and the wall of the storage vessel in a continuous fashion except as allowed in sub. (4) (b) 4.
NR 440.285(3)(a)2.b.
b. Except for automatic bleeder vents and rim space vents, each opening in a noncontact external floating roof shall provide a projection below the liquid surface. Except for automatic bleeder vents, rim space vents, roof drains, and leg sleeves, each opening in the roof is to be equipped with a gasketed cover, seal, or lid that is to 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 are to be closed at all times when the roof is floating except when the roof is being floated off or is being landed on the roof leg supports. Rim vents are to be set to open when the roof is being floated off the roof leg supports or at the manufacturer's recommended setting. Automatic bleeder vents and rim space vents are to be gasketed. Each emergency roof drain is to be provided with a slotted membrane fabric cover that covers at least 90% of the area of the opening.
NR 440.285(3)(a)2.c.
c. The roof shall be floating on the liquid at all times (i.e., off the roof leg supports) except during initial fill until the roof is lifted off leg supports and when the storage vessel is completely emptied and subsequently refilled. The process of filling, emptying, or refilling when the roof is resting on the leg supports shall be continuous and shall be accomplished as rapidly as possible.
NR 440.285(3)(a)3.
3. A closed vent system and control device meeting the following specifications:
NR 440.285(3)(a)3.a.
a. The closed vent system shall be designed to collect all VOC vapors and gases discharged from the storage vessel and operated with no detectable emissions as indicated by an instrument reading of less than 500 ppm above background and visual inspections, as determined in
s. NR 440.62 (6) (b).
NR 440.285(3)(a)3.b.
b. The control device shall be designed and operated to reduce inlet VOC emissions by 95% or greater. If a flare is used as the control device, it shall meet the specifications described in the general control device requirements under
s. NR 440.18.
NR 440.285(3)(b)
(b) The owner or operator of each storage vessel with a design capacity greater than or equal to 75 m
3 which contains a VOL that, as stored, has a maximum true vapor pressure greater than or equal to 76.6 kPa shall equip each storage vessel with one of the following:
NR 440.285(4)
(4) Testing and procedures. The owner or operator of each storage vessel as specified in
sub. (3) (a) shall meet the requirements of
par. (a),
(b), or
(c). The applicable paragraph for a particular storage vessel depends on the control equipment installed to meet the requirements of
sub. (3).
NR 440.285(4)(a)
(a) After installing the control equipment required to meet
sub. (3) (a) 1. (permanently affixed roof and internal floating roof), each owner or operator shall:
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)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 cm
2 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.
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.
NR 440.285(4)(b)6.b.
b. For all the inspections required by this subdivision, the owner or operator shall notify the department in writing at least 30 days prior to the filling or refilling of each storage vessel to afford the department the opportunity to inspect the storage vessel prior to refilling. If the inspection required by this subdivision 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)(c)
(c) The owner or operator of each source that is equipped with a closed vent system and control device as required in
sub. (3) (a) 3. or
(b) 2. (other than a flare) is exempt from
s. NR 440.08 and shall meet the following requirements:
NR 440.285(4)(c)1.a.
a. Documentation demonstrating that the control device will achieve the required control efficiency during maximum loading conditions. This documentation shall include a description of the gas stream which enters the control device, including flow and VOC content under varying liquid level conditions (dynamic and static) and manufacturer's design specifications for the control device. If the control device or the closed vent capture system receives vapors, gases, or liquids other than fuels from sources that are not designated sources under this section, the efficiency demonstration shall include consideration of all vapors, gases, and liquids received by the closed vent capture system and control devices. If an enclosed combustion device with a minimum residence time of 0.75 seconds and a minimum temperature of 816
°C is used to meet the 95% requirement, documentation that those conditions will exist is sufficient to meet the requirements of this paragraph.
NR 440.285(4)(c)1.b.
b. A description of the parameter or parameters to be monitored to ensure that the control device will be operated in conformance with its design and an explanation of the criteria used for selection of that parameter (or parameters).
NR 440.285(4)(c)2.
2. Operate the closed vent system and control device and monitor the parameters of the closed vent system and control device in accordance with the operating plan submitted to the department in accordance with
subd. 1., unless the plan was modified by the department during the review process. In this case, the modified plan applies.
NR 440.285(4)(d)
(d) The owner or operator of each source that is equipped with a closed vent system and a flare to meet the requirements in
sub. (3) (a) 3. or
(b) 2. shall meet the requirements as specified in the general control device requirements under
s. NR 440.18 (5) and
(6).
NR 440.285(5)(a)(a) If, in the administrator's judgment, an alternative means of emission limitation will achieve a reduction in emissions at least equivalent to the reduction in emissions achieved by any requirement in
sub. (3), the administrator will publish in the federal register a notice permitting the use of the alternative means for purposes of compliance with that requirement.
NR 440.285(5)(b)
(b) Any notice under
par. (a) will be published only after notice and an opportunity for a public hearing.
NR 440.285(5)(c)
(c) Any person seeking permission under this section shall submit to the administrator a written application including:
NR 440.285(5)(c)1.
1. An actual emissions test that uses a full-sized or scale-model storage vessel that accurately collects and measures all VOC emissions from a given control device and that accurately simulates wind and accounts for other emission variables such as temperature and barometric pressure.
NR 440.285(5)(c)2.
2. An engineering evaluation that the administrator determines is an accurate method of determining equivalence.
NR 440.285(5)(d)
(d) The administrator may condition the permission on requirements that may be necessary to ensure operation and maintenance to achieve the same emission reduction as specified in
sub. (3).
NR 440.285(6)
(6) Reporting and recordkeeping requirements. The owner or operator of each storage vessel as specified in
sub. (3) (a) shall keep records and furnish reports as required by
par. (a),
(b), or
(c) depending upon the control equipment installed to meet the requirements of
sub. (3). The owner or operator shall keep copies of all reports and records required by this section, except for the record required by
par. (c) 1., for at least 2 years. The record required by
par. (c) 1. will be kept for the life of the control equipment.
NR 440.285(6)(a)
(a) After installing control equipment in accordance with
sub. (3) (a) 1. (fixed roof and internal floating roof), the owner or operator shall meet the following requirements:
NR 440.285(6)(a)1.
1. Furnish the department with a report that describes the control equipment and certifies that the control equipment meets the specifications of
subs. (3) (a) 1. and
(4) (a) 1. This report shall be an attachment to the notification required by
s. NR 440.07 (1) (c).
NR 440.285(6)(a)2.
2. Keep a record of each inspection performed as required by
sub. (4) (a) 1. to
4. Each record shall identify the storage vessel on which the inspection was performed and shall contain the date the vessel was inspected and the observed condition of each component of the control equipment (seals, internal floating roof, and fittings).
NR 440.285(6)(a)3.
3. If any of the conditions described in
sub. (4) (a) 2. are detected during the annual visual inspection required by
sub. (4) (a) 2., a report shall be furnished to the department within 30 days of the inspection. Each report shall identify the storage vessel, the nature of the defects, and the date the storage vessel was emptied or the nature of and date the repair was made.
NR 440.285(6)(a)4.
4. After each inspection required by
sub. (4) (a) 3. that finds holes or tears in the seal or seal fabric, defects in the internal floating roof, or other control equipment defects listed in
sub. (4) (a) 3. b., a report shall be furnished to the department within 30 days of the inspection. The report shall identify the storage vessel and the reason it did not meet the specifications of
sub. (3) (a) 1. or
(4) (a) 3. and list each repair made.
NR 440.285(6)(b)
(b) After installing control equipment in accordance with
sub. (3) (a) 2. (external floating roof), the owner or operator shall meet the following requirements:
NR 440.285(6)(b)1.
1. Furnish the department with a report that describes the control equipment and certifies that the control equipment meets the specifications of
subs. (3) (a) 2. and
(4) (b) 2. to
4. This report shall be an attachment to the notification required by
s. NR 440.07 (1) (c).
NR 440.285(6)(b)2.
2. Within 60 days of performing the seal gap measurements required by
sub. (4) (b) 1., furnish the department with a report that contains:
NR 440.285(6)(b)3.
3. Keep a record of each gap measurement performed as required by
sub. (4) (b). Each record shall identify the storage vessel in which the measurement was performed and shall contain:
NR 440.285(6)(b)4.
4. After each seal gap measurement that detects gaps exceeding the limitations specified by
sub. (4) (b) 4., submit a report to the department within 30 days of the inspection. The report will identify the vessel and contain the information specified in
par. (b) 2. and the date the vessel was emptied or the repairs made and date of repair.
NR 440.285(6)(c)
(c) After installing control equipment in accordance with
sub. (3) (a) 3. or
(b) 1. (closed vent system and control device other than a flare), the owner or operator shall keep the following records:
NR 440.285(6)(d)
(d) After installing a closed vent system and flare to comply with
sub. (3), the owner or operator shall meet the following requirements:
NR 440.285(6)(d)1.
1. A report containing the measurements required by
s. NR 440.18 (6) shall be furnished to the department as required by
s. NR 440.08. This report shall be submitted within 6 months of the initial startup date.
NR 440.285(6)(d)2.
2. Records shall be kept of all periods of operation during which the flare pilot flame is absent.
