Practice and analysis of life measuring device for motor valve

Motor valve leakage is not easy to detect during using, so it must carry out quality inspection before assembly into gas meter. The quality appraisement of valve mainly relies on switch times before leakage, and pressure difference measurement is better method for leakage judgment. The static pressure leak detection method, reference gas chamber and control program of solenoid valve are key technologies in pressure difference measurement and life measurement. The new type device is designed with hardware and software, such as gas path and pipes, sensor, the solenoid valves of dynamic structure static switching unit, controller, gas pressure regulation system, automatic detection and valve switching process control program etc. Based on support of hardware and software, dynamic flow pipe is separated to static segments which are reference gas chamber and measuring air chambers; and the signal of chambers' pressure difference and switch times without leakage are the output result. Switching frequency ratio of solenoid valves to motor valve is 1:5 or 1:10; lower ratio can prolong the service life of solenoid valves. The motor valve is kind of key part in natural gas measurement instrument, because the leakage of motor valve can induce the whole production useless. In producing process, it is difficulty thing for instrument producer to get valve's switch times before leakage for every valve. Therefore, valve leakage tests are usually done by randomly selected units from batch valve wares before use, and leakage state and life are estimated for the whole valves, named spot check instead fully inspection. Nevertheless, leakage test is also a low efficiency work, usually manual work and single test. For the reasons of long period of time to spend and characteristics of consumption test, it is always no test in practice, there are latent safety problems and production quality problems in producing process. In order to complete batch test automatically, a new device for motor valve life measurement is developed here.