The utility model is especially suitable for the drainingvalve with big caliber and big displacement.
对大口径、大排量疏水阀尤为实用。
2
The utility model can prevent the discharge-orifice steel columns of the upper drainingvalve cover from cracking, increase the service life of oil-well pumps, and lower oil-production cost.
本实用新型可防止抽油泵在采油过程中上排出阀罩出油孔筋柱裂断，提高抽油泵的使用寿命，降低采油成本。
3
When boiler need big volume draining or level regulation valve failed to work, there should open bypass valve to draining.