Except for unattended field compressor stations of 1,000 horsepower (746 kilowatts) or less, each compressor station must have an emergency shutdown system that meets the following.
(a) It must be able to block gas out of the station and blow down the station piping.
(b) It must discharge gas from the blowdown piping at a location where the gas will not create a hazard.
(c) It must provide means for extinguishing gas fires and for the shutdown of gas compressing equipment, and electrical facilities in the vicinity of gas headers and in the compressor building, except that electrical circuits that supply emergency lighting required to assist station personnel in evacuating the compressor building and the area in the vicinity of the gas headers must remain energized and electrical circuits needed to protect equipment from damage may remain energized.
(d) It must be operable from at least two locations, each of which is:
(1) outside the gas area of the station;
(2) near the exit gates, if the station is fenced, or near emergency exits, if not fenced; and
(3) not more than 500 feet (152.4 meters) from the limits of the station.
(e) If a compressor station supplies gas directly to a distribution system with no other adequate sources of gas available, the emergency shutdown system must be designed so that it will not function at the wrong time and cause an unintended outage on the distribution system.