Pressure test is also called strength test. The test pressure is 1.5 times of the nominal pressure. The pressurized medium for the test is pure water, and the chloride ion content should not exceed 25ppm. Each product shall be subject to withstand voltage test. Manual or electric pressure test pump shall be used for pressurization, and pressure observation can usually be performed with a pressure gauge of 1.5-4 times the test pressure range, or a pressure test instrument with equivalent efficacy. During the test, place the hose test piece straight, install a plug with an exhaust valve at one end, and connect the other end with the outlet pipe of the pressure test pump. Inject water into the pipe, exhaust the air, close the exhaust valve, and then slowly increase the pressure to the specified test pressure value. After maintaining the pressure for 5mm, check the condition of the test sample to see if there are any abnormal failure forms such as leakage and parts damage. Qualified products are required not to have abnormal failure forms such as leakage signs or parts damage.

Inspection items and methods there are mainly seven performance inspection indicators of metal bellows: appearance, size, pressure resistance, air tightness, static bending, dynamic bending and blasting. Among them, appearance, size, pressure resistance and air tightness are factory inspection items, and all seven items are required to be inspected during type test. This paper mainly discusses five items: pressure resistance, air tightness, static bending, dynamic bending and blasting.