Purging of Pipelines

§ 192.629 Purging of Pipelines#

(a)When a pipeline is being purged of air by use of gas, the gas must be released into one end of the line in a moderately rapid and continuous flow. If gas cannot be supplied in sufficient quantity to prevent the formation of a hazardous mixture of gas and air, a slug of inert gas must be released into the line before the gas.#

(b)When a pipeline is being purged of gas by use of air, the air must be released into one end of the line in a moderately rapid and continuous flow. If air cannot be supplied in sufficient quantity to prevent the formation of a hazardous mixture of gas and air, a slug of inert gas must be released into the line before the air.#

(c)When a low pressure gas system is being purged of water by natural gas, the allowable operating pressure may not be exceeded. If the pressure required to purge the water exceeds the established maximum allowable operating pressure, air will be used to purge the system.#