What is the meaning of the primary valve secondary valve of the oil filter?

　　What is the meaning of the primary valve secondary valve of the oil filter?

 

　　The primary valve, also known as the source valve, is the first instrument valve that directly controls the flow of media into the instrument's pressure guiding tube or instrumentation. Its purpose is to prevent the pipeline from spilling, clogging and cutting off the medium. The primary valve is part of the source component.

　　The secondary valve is relative to the primary valve and is located downstream of the primary valve.

 

　　For example, a condensate sampling valve generally uses two valves in series, and the valve close to the pipe is a primary valve.

 

　　It is commonly used in multiple pipelines on the vacuum oil filter machine to use multiple valves.