1. a) Each open-ended valve shall be equipped with a cap, blind flange, plug, or a second valve, except during operations requiring fluid flow through the open-ended valve.
2. b) Each open-ended valve equipped with a second valve shall be operated in a manner such that the valve on the process fluid end is closed before the second valve is closed.

3. c) Components which are open-ended valves and which serve as a sampling connection shall be controlled such that:

   1. 1) A closed purge system or closed vent system shall return purged process fluid to the process line with no detectable volatile organic material emissions to the atmosphere, or
   2. 2) A closed purge system or closed vent system shall collect and recycle purged process fluid to the process line with no detectable volatile organic material emissions to the atmosphere, or
   3. 3) Purged process fluid shall be transported to a control device that complies with the requirements of Section 215.438.
4. d) In-situ sampling systems are exempt from subsection (c).

(Source: Amended at 13 Ill. Reg. 10893, effective June 27, 1989)