When the hydraulic test of the PTFE-lined metal hose is not enough to reflect the pressure test requirements of each point, or it is not suitable for the hydraulic test due to other reasons, the pneumatic test at the expansion joint can be considered.
When the PTFE-lined metal hose is subjected to air pressure test, there must be reliable protective measures on site. The air pressure test medium is usually dry, clean air, and can also be nitrogen or other inert gases. The test temperature also has certain requirements. When the connecting pipe is a carbon steel and low alloy steel expansion joint, the temperature used for testing should not be lower than 15°C, and other materials should be tested according to the pattern. After the official production of the product, the structure, material and process have changed greatly and may affect the performance of the expansion joint; production is resumed after a long-term shutdown; when the labor department conducts manufacturing qualification certification or the quality supervision agency requires a quality inspection, a series of inspections must be done. performance test. The main items of the test are: pressure test, airtight test, stress measurement, stiffness measurement, stability test, fatigue test and burst test. All tests of PTFE-lined metal hoses should follow the requirements of relevant national or industry standards and technical conditions, and can also refer to foreign standards and technical conditions for expansion joints.
Pneumatic test and hydraulic test of metal hose lined with PTFE
Before leaving the factory, the PTFE-lined metal hose products must undergo a pressure test according to regulations. The purpose of the test is to test the macroscopic strength of the high-temperature metal hose under super-working load conditions, and to test whether the high-temperature compensator has the ability to operate under the design load. At the same time, it can test the compactness of the expansion joint, and check the material, structure and manufacturing process. possible problems in .
