Code of Federal Regulations Title 40. Protection of Environment § 40.65.111 Standards:  Pressure relief devices in gas/vapor service

(a) Compliance schedule. The owner or operator shall comply with this section no later than the implementation date specified in § 65.1(f).

(b) Compliance standard. Except during pressure releases as provided for in paragraph (c) of this section, each pressure relief device in gas/vapor service shall be operated with an instrument reading of less than 500 parts per million as measured by the method specified in § 65.104(b) and (c).

(c) Pressure relief requirements.

(d) Pressure relief devices routed to a process or fuel gas system or equipped with a closed vent system and control device. Any pressure relief device that is routed to a process or fuel gas system or equipped with a closed vent system capable of capturing and transporting leakage from the pressure relief device to a control device meeting the requirements of § 65.115 is exempt from the requirements of paragraphs (b) and (c) of this section.

(e) Rupture disk exemption. Any pressure relief device that is equipped with a rupture disk upstream of the pressure relief device is exempt from the requirements of paragraphs (b) and (c) of this section provided the owner or operator installs a new rupture disk upstream of the pressure relief device as soon as practical after each pressure release, but no later than 5 calendar days after each pressure release except as provided in § 65.105(d).