Section 63.691 - Standards: Equipment leaks(a) The provisions of this section apply to the control of air emissions from equipment leaks for which § 63.683(d) references the use of this section for such air emissions control.(b) According to the date an affected source commenced construction or reconstruction and the date an affected source receives off-site material for the first time, as established in § 63.680(e)(i) through (iii) , the owner or operator shall control the HAP emitted from equipment leaks in accordance with the applicable provisions specified in either paragraph (b)(1) or (2) of this section. (1)(i) The owner or operator controls the HAP emitted from equipment leaks in accordance with §§ 61.241 through 61.247 in 40 CFR part 61, subpart V-National Emission Standards for Equipment Leaks, with the difference noted in paragraphs (b)(1)(iii) and (iv) of this section for the purposes of this subpart; or(ii) The owner or operator controls the HAP emitted from equipment leaks in accordance with §§ 63.161 through 63.182 in subpart H of this part-National Emission Standards for Organic Hazardous Air Pollutants from Equipment Leaks, with the differences noted in paragraphs (b)(2)(i) through (iv) of this section for the purposes of this subpart.(iii) On or after March 18, 2015, for the purpose of complying with the requirements of 40 CFR 61.242-6(a)(2) or the requirements of § 63.167(a)(2) , the open end is sealed when instrument monitoring of the open-ended valve or line conducted according to Method 21 of 40 CFR part 60, appendix A indicates no readings of 500 ppm or greater.(iv) On or after March 18, 2015, for the purpose of complying with the requirements of 40 CFR 61.242-6(d) or the requirements of § 63.167(d) , open-ended valves or lines in an emergency shutdown system which are designed to open automatically in the event of a process upset and that are exempt from the requirements in 40 CFR 61.242-6(a), (b), and (c) or § 63.167(a), (b), and (c) must comply with the requirements in § 63.693(c)(2) .(2) The owner or operator controls the HAP emitted from equipment leaks in accordance with §§ 63.161 through 63.183 in subpart H of this part-National Emission Standards for Organic Hazardous Air Pollutants for Equipment Leaks, with the differences noted in paragraphs (b)(2)(i) through (v) of this section for the purposes of this subpart. (i) For each valve in gas/vapor or in light liquid service, as defined in § 63.681 , that is part of an affected source under this subpart, an instrument reading that defines a leak is 500 ppm or greater as detected by Method 21 of 40 CFR part 60, appendix A.(ii) For each pump in light liquid service, as defined in § 63.681 , that is part of an affected source under this subpart, an instrument reading that defines a leak is 1,000 ppm or greater as detected by Method 21 of 40 CFR part 60, appendix A. Repair is not required unless an instrument reading of 2,000 ppm or greater is detected.(iii) On or after March 18, 2015, for the purpose of complying with the requirements of § 63.167(a)(2) , the open end is sealed when instrument monitoring of the open-ended valve or line conducted according to Method 21 of 40 CFR part 60, appendix A indicates no readings of 500 ppm or greater.(iv) On or after March 18, 2015, for the purpose of complying with the requirements of § 63.167(d) , open-ended valves or lines in an emergency shutdown system which are designed to open automatically in the event of a process upset and that are exempt from the requirements in § 63.167(a), (b), and (c) must comply with the requirements in § 63.693(c)(2) .(v) For the purposes of this subpart, the pressure relief device requirements of § 63.691(c) of this subpart rather than those of § 63.165 or of 40 CFR 61.242-4 , as applicable, shall apply. The pressure relief device requirements of § 63.691(c)(3) and (4) apply in addition to the requirements of § 63.169 or of 40 CFR 61.242-8 , as applicable, for pressure relief devices in liquid service.(c)Requirements for pressure relief devices. Except as provided in paragraph (c)(4) of this section, the owner or operator must comply with the requirements specified in paragraphs (c)(1) through (3) of this section for pressure relief devices in off-site material service. (1)Operating requirements. Except during a pressure release event, operate each pressure relief device in gas/vapor service with an instrument reading of less than 500 ppm above background as detected by Method 21 of 40 CFR part 60, appendix A.(2)Pressure release requirements. For pressure relief devices in gas/vapor service, the owner or operator must comply with either paragraph (c)(2)(i) or (ii) of this section following a pressure release, as applicable. (i) If the pressure relief device does not consist of or include a rupture disk, the pressure relief device shall be returned to a condition indicated by an instrument reading of less than 500 ppm above background, as detected by Method 21 of 40 CFR part 60, appendix A, no later than 5 calendar days after the pressure release device returns to off-site material service following a pressure release, except as provided in § 63.171 .(ii) If the pressure relief device consists of or includes a rupture disk, except as provided in § 63.171 , install a replacement disk as soon as practicable but no later than 5 calendar days after the pressure release.(3)Pressure release management. Except as provided in paragraph (c)(4) of this section, emissions of HAP listed in Table 1 of this subpart may not be discharged directly to the atmosphere from pressure relief devices in off-site material service, and according to the date an affected source commenced construction or reconstruction and the date an affected source receives off-site material for the first time, as established in § 63.680(e)(1)(i) through (iii) , the owner or operator must comply with the requirements specified in paragraphs (c)(3)(i) and (ii) of this section for all pressure relief devices in off-site material service, except that containers are not subject to the obligations in paragraph (c)(3)(i) of this section.(i) The owner or operator must equip each pressure relief device in off-site material service with a device(s) or use a monitoring system. The device or monitoring system may be either specific to the pressure release device itself or may be associated with the process system or piping, sufficient to indicate a pressure release to the atmosphere. Examples of these types of devices or monitoring systems include, but are not limited to, a rupture disk indicator, magnetic sensor, motion detector on the pressure relief valve stem, flow monitor, pressure monitor, or parametric monitoring system. The devices or monitoring systems must be capable of meeting the requirements specified in paragraphs (c)(3)(i)(A) through (C) of this section.(A) Identifying the pressure release;(B) Recording the time and duration of each pressure release; and(C) Notifying operators immediately that a pressure release is occurring.(ii) If any pressure relief device in off-site material service releases directly to the atmosphere as a result of a pressure release event, the owner or operator must calculate the quantity of HAP listed in Table 1 of this subpart released during each pressure release event and report this quantity as required in § 63.697(b)(5) . Calculations may be based on data from the pressure relief device monitoring alone or in combination with process parameter monitoring data and process knowledge. For containers, the calculations may be based on process knowledge and information alone.(4)Pressure relief devices routed to a drain system, fuel gas system, process or control device. If a pressure relief device in off-site material service is designed and operated to route all pressure releases through a closed vent system to a drain system, fuel gas system, process or control device, paragraphs (c)(1), (2), and (3) of this section do not apply. The fuel gas system or closed vent system and the process or control device (if applicable) must meet the requirements of § 63.693 . The drain system (if applicable) must meet the requirements of § 63.689 .64 FR 38970, July 20, 1999, as amended at 66 FR 1266 , Jan. 8, 2001; 80 FR 14275 , Mar. 18, 2015; 83 FR 3992 , Jan. 29, 2018