Section 65.143 - Closed vent systems(a)Closed vent system equipment and operating requirements. The provisions of paragraph (a) of this section apply to closed vent systems collecting regulated material from a storage vessel, process vent, transfer rack, or equipment leaks.(1)Collection of emissions. Each closed vent system shall be designed and operated to collect the regulated material vapors from the emission point and to route the collected vapors to a control device.(2)Period of operation. Closed vent systems used to comply with the provisions of this subpart shall be operated at all times when emissions are vented to them.(3)Bypass monitoring. Except for pressure relief devices needed for safety purposes, low leg drains, high point bleeds, analyzer vents, and open-ended valves or lines, the owner or operator shall comply with either of the following provisions for each closed vent system that contains bypass lines that could divert a vent stream to the atmosphere:(i) Properly install, maintain, and operate a flow indicator that takes a reading at least once every 15 minutes. Records shall be generated as specified in § 65.163(a)(1)(i) . The flow indicator shall be installed at the entrance to any bypass line.(ii) Secure the bypass line valve in the non-diverting position with a car-seal or a lock-and-key type configuration. A visual inspection of the seal or closure mechanism shall be performed at least once every month to ensure the valve is maintained in the non-diverting position and the vent stream is not diverted through the bypass line. Records shall be generated as specified in § 65.163(a)(1)(ii) .(4)Loading arms at transfer racks. Each closed vent system collecting regulated material from a transfer rack shall be designed and operated so that regulated material vapors collected at one loading arm will not pass through another loading arm in the rack to the atmosphere.(5)Pressure relief devices in a transfer rack's closed vent system. The owner or operator of a transfer rack subject to the provisions of this subpart shall ensure that no pressure relief device in the transfer rack's closed vent system shall open to the atmosphere during loading. Pressure relief devices needed for safety purposes are not subject to paragraph (a)(5) of this section.(b)Closed vent system inspection requirements. The provisions of paragraph (b) of this section apply to closed vent systems collecting regulated material from a storage vessel, transfer rack or equipment leaks. Inspection records shall be generated as specified in § 65.163(a)(3) and (4) .(1) Except for closed vent systems operated and maintained under negative pressure and as provided in paragraphs (b)(2) and (3) of this section, each closed vent system shall be inspected as specified in paragraph (b)(1)(i) or (ii) of this section.(i) If the closed vent system is constructed of hard-piping, the owner or operator shall comply with the following requirements:(A) Conduct an initial inspection according to the procedures in paragraph (c) of this section; and(B) Conduct annual visual inspections for visible, audible, or olfactory indications of leaks.(ii) If the closed vent system is constructed of ductwork, the owner or operator shall conduct an initial and annual inspection according to the procedures in paragraph (c) of this section.(2) Any parts of the closed vent system that are designated as described in § 65.163(a)(2) as unsafe to inspect are exempt from the inspection requirements of paragraph (b)(1) of this section if the following conditions are met: (i) The owner or operator determines that the equipment is unsafe to inspect because inspecting personnel would be exposed to an imminent or potential danger as a consequence of complying with paragraph (b)(1) of this section; and(ii) The owner or operator has a written plan that requires inspection of the equipment as frequently as practical during safe-to-inspect times. Inspection is not required more than once annually.(3) Any parts of the closed vent system that are designated, as described in § 65.163(a)(2) , as difficult-to-inspect are exempt from the inspection requirements of paragraph (b)(1) of this section if the following provisions apply: (i) The owner or operator determines that the equipment cannot be inspected without elevating the inspecting personnel more than 2 meters (7 feet) above a support surface; and(ii) The owner or operator has a written plan that requires inspection of the equipment at least once every 5 years.(c)Closed vent system inspection procedures. The provisions of paragraph (c) of this section apply to closed vent systems collecting regulated material from a storage vessel, transfer rack, or equipment leaks. (1) Each closed vent system subject to paragraph (c) of this section shall be inspected according to the procedures specified in paragraphs (c)(1)(i) through (vii) of this section. (i) Inspections shall be conducted in accordance with Method 21 of appendix A of 40 CFR part 60 except as specified in this section.(ii) Except as provided in paragraph (c)(1)(iii) of this section, the detection instrument shall meet the performance criteria of Method 21 of appendix A of 40 CFR part 60, except the instrument response factor criteria in section 3.1.2(a) of Method 21 shall be for the representative composition of the process fluid not each individual organic compound in the stream. For process streams that contain nitrogen, air, water, or other inerts that are not organic hazardous air pollutants or volatile organic compounds, the response factor shall be determined on an inert-free basis. The response factor may be determined at any concentration for which the monitoring for leaks will be conducted. Maintain the record specified by § 65.163(a)(5) .(iii) If no instrument is available at the plant site that will meet the performance criteria specified in paragraph (c)(1)(ii) of this section, the instrument readings may be adjusted by multiplying by the representative response factor of the process fluid calculated on an inert-free basis as described in paragraph (c)(1)(ii) of this section.(iv) The detection instrument shall be calibrated before use on each day of its use by the procedures specified in Method 21 of appendix A of 40 CFR part 60.(v) Calibration gases shall be as specified in the following:(A) Zero air (less than 10 parts per million hydrocarbon in air).(B) Mixtures of methane in air at a concentration less than 10,000 parts per million. A calibration gas other than methane in air may be used if the instrument does not respond to methane or if the instrument does not meet the performance criteria specified in paragraph (c)(1)(ii) of this section. In such cases, the calibration gas may be a mixture of one or more of the compounds to be measured in air.(C) If the detection instrument's design allows for multiple calibration scales, then the lower scale shall be calibrated with a calibration gas that is no higher than 2,500 parts per million.(vi) An owner or operator may elect to adjust or not adjust instrument readings for background. If an owner or operator elects not to adjust readings for background, all such instrument readings shall be compared directly to 500 parts per million to determine whether there is a leak. If an owner or operator elects to adjust instrument readings for background, the owner or operator shall measure background concentration using the procedures in this section. The owner or operator shall subtract the background reading from the maximum concentration indicated by the instrument.(vii) If the owner or operator elects to adjust for background, the arithmetic difference between the maximum concentration indicated by the instrument and the background level shall be compared with 500 parts per million for determining whether there is a leak.(2) The instrument probe shall be traversed around all potential leak interfaces as close to the interface as possible as described in Method 21 of appendix A of 40 CFR part 60.(3) Except as provided in paragraph (c)(4) of this section, inspections shall be performed when the equipment is in regulated material service or in use with any other detectable gas or vapor.(4) Inspections of the closed vent system collecting regulated material from a transfer rack shall be performed only while a tank truck or railcar is being loaded or is otherwise pressurized to normal operating conditions with regulated material or any other detectable gas or vapor.(d)Closed vent system leak repair provisions. The provisions of paragraph (d) of this section apply to closed vent systems collecting regulated material from a storage vessel, transfer rack, or equipment leak. (1) If there are visible, audible, or olfactory indications of leaks at the time of the annual visual inspections required by paragraph (b)(1)(i)(B) of this section, the owner or operator shall follow either of the following procedures:(i) The owner or operator shall eliminate the indications of the leak.(ii) The owner or operator shall monitor the equipment according to the procedures in paragraph (c) of this section.(2) Leaks as indicated by an instrument reading greater than 500 parts per million by volume above background shall be repaired as soon as practical except as provided in paragraph (d)(3) of this section. Records shall be generated as specified in § 65.163(a)(3) when a leak is detected. (i) A first attempt at repair shall be made no later than 5 calendar days after the leak is detected.(ii) Except as provided in paragraph (d)(3) of this section, repairs shall be completed no later than 15 calendar days after the leak is detected or at the beginning of the next introduction of vapors to the system, whichever is later.(3) Delay of repair of a closed vent system for which leaks have been detected is allowed if repair within 15 days after a leak is detected is technically infeasible without a closed vent system shutdown, as defined in § 65.2 , or if the owner or operator determines that emissions resulting from immediate repair would be greater than the emissions likely to result from delay of repair. Repair of such equipment shall be completed as soon as practical, but not later than the end of the next closed vent system shutdown.