After using a micro vacuum pump to evacuate a closed container, some customers hope that the vacuum in the container can still be maintained for a long time after the micro vacuum pump is powered off. That is to say, the pump at this time is required to have the function of a valve and can cut off the vacuum. gas path to prevent gas from entering the container and causing the vacuum to disappear, that is, the pump requires a pressure maintaining function.
The micro vacuum pump is only a power component of the gas system. Providing power to the system is its main responsibility. The function of the valve cannot be pinned on the pump. When designing micro vacuum pumps, we mainly pursue parameters such as vacuum degree, flow rate, operational reliability, and stability. There are indeed two one-way valves inside the pump, but our design goal for them is to make them cooperate with the diaphragm movement to change the airflow as efficiently and reliably as possible during the operation of the pump. What we pursue is dynamic performance, not strict static performance. Turn off functionality.
The pressure-holding performance of our micro vacuum pump is very good under dynamic conditions, and the leakage rate is very low (complete leakage is an ideal state and impossible to achieve). There is data for reference: 10^ -7Pa M^3/S (10 minus 7 Pa cubic meters per second), but under static conditions (when the pump is powered off and stops working), air tightness is not required.
From design to production, the pump parameters are pursued instead of the valve parameters. Therefore, it is unscientific to require the pump to close the air path as tightly as a valve when it is stationary. A valve should be used to perform this function.
The one-way valve inside the pump has a certain closing ability when it is static. The better it is closed, the longer the vacuum can be maintained. However, pressure-holding performance is not the goal we pursue during design, and this test is not performed during production. Imported brands do not promise customers the holding time as a hard indicator, and according to our measurements, it varies widely. If the customer requests it, we can take this indicator into account through overproduction and then selection. Obviously, the production cost will increase significantly.
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