Piping airtightness test

Clause 9.2 of GB/T20801.5-2020 states that for pipes of GC1 grade (toxicity) and GC1 and GC2 grades (flammability), sensitivity leakage tests shall be carried out in accordance with 9.2.1. Piping systems that have passed the 9.1.4 gas test and have not been disassembled after the test may not require further testing. With the consent of the owner’s designer and the installation inspector, the airtightness test specified in 9.2.2 may be used in place of the test in 9.2.1; no detectable leaks shall be considered acceptable.

The airtightness test of pipelines (also known as a pressure test or leak test) is carried out to ensure the safety and integrity of the pipeline system. Pipeline codes typically contain specific provisions and requirements to guide when such tests should be performed. Airtightness testing is usually carried out in the following situations: 1. **New pipeline systems**: New pipeline systems must undergo airtightness testing before being put into use, to prove that they will not leak under the specified operating pressure. 2. **After maintenance or modification of the piping system**: If the piping system has undergone major repairs or significant modifications (such as replacing certain pipe fittings, welds, etc.), a leak test should be conducted before it is put back into use. 3. **Regular inspections**: As required by the regulations, existing pipeline systems must be inspected on a regular basis; this may include airtightness tests to ensure that the pipelines remain intact and safe over time. 4. **After an accident or abnormal operation**: If the piping system suffers an accident or goes through an abnormal operation, it may be affected in terms of safety; in such cases, a gas-tightness test should be conducted to verify its safety and reliability. 5. **In accordance with the specified service life**: Some pipeline systems may require regular airtightness tests based on their service life or operating cycle requirements. 6. **Specific operating pressure and medium requirements**: For pipelines that carry special media (such as gases, flammable and explosive liquids, etc.) or operate at high pressures, the standards impose stricter testing requirements. 7. **In accordance with regulations and standards**: Different countries and regions have various regulatory and industry standards, such as ASME, API, GB, etc. These regulations and standards specify under what circumstances a gas tightness test is required. The airtightness test of pipelines can use different media (such as air, nitrogen, water, etc.) and various testing methods. When conducting experiments, it is necessary to strictly adhere to relevant regulations, standards, and safety procedures. If a leak is detected during testing, it must be repaired and retested before it can be put into official use. .