After installation of the piping system, air or steam may be used for cleaning according to the working conditions of the working medium and the degree of dirt on the inner surface of the pipe. The general requirements for pipe purging are:

Equipment and pipes that are not allowed to be purged should be isolated from the purging system.

Before the pipeline is purged, orifice plates, flanged control valves, main valves, throttles, safety valves, meters, etc. should not be installed. For the above valves and meters connected by welding, they should be bypassed or sealed Protection measures. The purging sequence should be performed in the order of the main pipe, branch pipe, and drainage pipe, and the blown-out dirt should not enter the pipeline that has been purged.

The dirt discharged by purge shall not pollute the environment, and random discharge is strictly prohibited.

A restricted area should be set before purging.

No other operations affecting cleaning shall be performed after the pipeline has been purged.

1. After the strength test of the pipeline system, before the air tightness test, purge and clean it in sections.

2. The cleaning method should be determined according to the requirements of the pipeline, the working medium and the degree of stolen goods on the inner surface of the pipeline. Liquid or gas pipelines with a nominal diameter of 600 mm or more should be manually cleaned. Air purging should be adopted for gas pipelines with water cleaning and a nominal diameter of less than 600mm. Steam piping should be used for steam pipelines, and non-thermal pipelines should not be steamed. The purging of the normal gas is generally performed in sequence in accordance with the main pipe, branch pipe, and drainage pipe.

3. Before the pipeline is purged, a detailed purging plan should be prepared and carried out in sections according to the system.

4. Blowing equipment and pipes are not allowed to be separated from the blowing system.

5. After the pipeline is purged and qualified, in addition to the prescribed inspection and restoration work, no other work affecting the cleaning of the pipeline shall be performed, and the Pipeline System Purge Record shall be completed.