Benefits and features:
· It has less influence by hydraulic resistance, and its seal surface also affected less by medium`s erosion.
· It saves great labor to open and close.
· It doesn`t disturb the medium`s flow and also doesn`t reduce the pressure to work.
· Simple, short, good function, being available in wide range.
· It is easy to cause erosion between seal surface and it is hard to maintaining.
· It takes long time to open and close for its large dimension.
· Its structure is complicated.