The computer data acquisition of pneumatic valve performance test device 2 at low temperature

the pneumatic valve industry with low temperature air valve test device ( Figure USES the impregnation method and the cooling method in two ways. Impregnation method low temperature test device is suitable for low temperature brake pneumatic valve, by the pneumatic valve at low temperature and low temperature check pneumatic valve. Cold method of low temperature test device is suitable for all kinds of pneumatic valve. Pneumatic valve pneumatic seat tightness test pressure at low temperature and continue time table of low temperature test allows the leakage rate are shown in table leakage detection method is shown in figure to measure the size of the container in the sink.
the device has focused on the test data storage, display and print function, this paper introduces a computer data acquisition based on computer pneumatic valve performance test device at low temperature. And it can realize automatic control of the liquid nitrogen tank pressurization system, can improve the test efficiency, timeliness, accuracy and safety of operation. According to the project such as computer technology and photoelectric technology applied in the test device is the development direction in the future.
low temperature technology overview
cryogenic fluid get more and more widely used, with the development of the technology in low temperature. Such as liquid nitrogen is widely used in industrial production, scientific research, medical and health, such as liquid nitrogen and liquid oxygen as a rocket propellant showed obvious advantages in the field of national defense. In addition, in recent years, with the energy shortage, liquefied natural gas (LNG) has become one of the main energy. Application of cryogenic liquid, pneumatic valve is the indispensable line accessories at low temperature. However, due to the much work on pneumatic valve - at low temperature ℃ ultra-low under your area, so the structure design, material selection, manufacturing process and inspection test and so on are put forward special requirements. Especially in cryogenic pneumatic valve product inspection, in addition to room temperature in the same general pneumatic valve to meet the various performance test requirements, low temperature performance test under the condition of inspection. Low temperature test is the main task of the pneumatic valve in the low temperature air tightness test and performance such as opening and closing. The test device is very important, the advanced nature of the device performance determines the accuracy and reliability of test results. Therefore developed a new type of pneumatic valve comprehensive test device at low temperature, features include two aspects of test at low temperature and cryogenic treatment, the temperature signal, pressure signal and pneumatic valve leakage automatic measurement was achieved by using a computer data acquisition system. The device has focused on the test data storage, display and print function. This paper focuses on the pneumatic valve performance test device at low temperature in pneumatic pneumatic valve seat sealing the content of the low temperature test. Status quo

low temperature test device actively carried out the research and development work. Because use of refrigeration and low temperature in a different way, involving the cryogenic pneumatic valve manufacturers at home and abroad and research institutions for low temperature low temperature performance of pneumatic valve test very seriously. Test unit decorate on there is a big difference. We often use a dipping method and the cooling method in two ways. Impregnation method ( The external cooling method of the pneumatic valve directly to a liquid nitrogen cooling in the cold box, when the temperature of the pneumatic valve temperature quenching to work again after sealing performance test using helium gas. Cold insulation method ( Namely, internal cooling method to pneumatic valve is installed in the cold box bao, ventilation with low temperature internal cooling medium into the pneumatic valve, when the temperature to a specified value, will release the medium at low temperature, and then pass into the by helium pressure test. And spray method, the pneumatic valve is installed in the cold box bao, using liquid nitrogen, into the spray head to protect cold box, when confirmed temperature to test the temperature in the cold box, stop the spray liquid nitrogen, and tested in accordance with the provisions, pressure ventilation with nitrogen. But spray method is not applicable to cryogenic pneumatic valves. Low temperature test device has the following several kinds of commonly used at home and abroad.
。 Japanese pneumatic valve industry with low temperature air valve test device