Sequence of purging and pressure testing

We always conduct pressure testing first to ensure that there are no leaks in the testing system and that it is safe overall, before proceeding with purging.

The SH standard was mentioned incidentally. After pressure testing, a thorough purging is carried out before the system can be put into operation.

A hydrostatic test should be carried out first, followed by cleaning; cleaning alone cannot serve the purpose of inspecting pipelines and equipment! Also, water can be used to flush the pipelines, removing impurities such as slag from within them. This also ensures the safety of the equipment and future production. This post was last edited by Yunshui Fengdu on 2009-3-14 19:28.]

In actual work, a hydrostatic test is carried out first, followed by line cleaning. Otherwise, rework is likely to occur.

In practice, a hydrostatic test is usually carried out first, followed by purging. The hydrostatic test checks for leaks; it also allows the pipelines to be cleaned, removing debris such as weld slag from within them ； Purging can sometimes prevent flammable substances inside a container from causing an explosion or deflagration. The machine can only be started after thorough purging

Hydraulic testing must be carried out first, followed by air purging

1. Except for water systems that use water flushing, other systems that employ compressed air and steam for purging must be purged after pressure testing; it’s not a matter of which method to use first, but rather it’s a required sequence. Because these systems require that any residual water be removed after pressure testing, in order to prevent surface rust formation and ensure that the cleanliness of the pipes meets the original purging requirements ； The purpose of purging is not only to remove debris from the pipes but also the water remaining after pressure testing. 2. For water-flushing systems, pressure testing should generally be carried out first before flushing; in the case of circulating water systems, pre-coating treatment is also necessary, otherwise the system will rust and solid impurities will end up in the water. If flushing is done first and then pressure testing is carried out, and if problems are detected during the pressure testing that require re-welding or repair (although this is unlikely, it’s still possible; otherwise there would be no need for pressure testing), then flushing must be done again. In summary, pressure testing should be done first followed by cleaning; the order cannot be reversed! This post was last edited by zhanong on 2009-3-24 13:03]

Generally, after the construction of the process pipelines or units is completed and the three inspections and four determinations have been carried out, hydraulic or gas tests are conducted on the pipelines or units; cleaning or purging can only be carried out once the pressure test is successful

Generally, purging is carried out after a hydrostatic test