Vacuum valve is used in a vacuum system to change the direction of airflow, adjust air mass flow and cut off or connect pipes in the vacuum system. Vacuum valve close parts are sealed by rubber or metal seal ring.
Vacuum electromagnetic valve is controlled by AC or DC power supply to turn on or off. It can use electromagnetic principle to realize the vacuum treatment on pipes, mainly used to vacuum pipes or linkage control system with vacuum pump. At the same time, it is directly operated by electromagnet and controls valves’ on/off. It fills atmosphere into vacuum container, realizing the automatic control or remote control.
Isweek also learnt that the realization of electromagnetic control can greatly affect the whole working status of pipe system and the usage of vacuum electromagnetic valves can also effectively avoid the impact of other irrelevant factors on the pipes, so as to make correct adjustment on pipe system.
When vacuum electromagnetic valves are mounted in mechanical vacuum pump, valves and pump are connected to the same power supply and the valves’ on/off are directly controlled by pump accordingly. When the pump stops working or power supply is cut off suddenly, valves will shut down vacuum system automatically. It fills air into pump chamber by the air inlet of pump to prevent pump oil flowing back to pollute vacuum system.
The most important point during the usage of vacuum valves is the sealability of valves, an ability of each sealing part of valves to prevent media leak, which is also the most important technical performance index. If the vacuum valves cannot be tightly closed and leakage occurs, the ability of valves to cut off media would be affected. For cut-off valve, the leakage is not allowed. Because leakage can cause material loss, pollute environment and even provoke serious accidents. Also for inflammable, explosive, toxic or radioactive media, the leakage is not allowed. Therefore, the valves must have a reliable sealability.
So how can we judge the sealing performance of vacuum valve?
Isweek suggests to use thermal conductivity gas sensor to detect vacuum degree of vacuum valves to assure their good sealing. The Endetec thermal conductivity gas sensor – MTCS2601 from France, acted by Isweek, owns the ability to detect vacuum degree based on Pirani principle with low power consumption, long lifetime, free maintenance and other benefits. This conductivity gas sensor is suitable for the primary pressure control in harsh environment. At the same time, there is heating resistor on silicon die, which can provide an excellent temperature compensation.
