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    Drainage device

 Drainage device is the important part of the oil well 

pump, which is mainly used for the sealed valve 

cages,For example, the whole barrel pump,special 

pump and so on .

Its function is drain off the oil in the down-hole

string when put forward in mining pump need  ground,

  Product details：

      Drainage device is the important part of the oil well  pump, which is mainly used for the sealed valve cages,For example, the whole barrel pump,special  pump and so on .Its function is drain off the oil in the down-hole  string when put forward in mining pump need
ground,

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