In the past, the multi-valve system consisting of check valve, globe valve and water hammer eliminator was widely used in the cooling and circulating water supply equipment of industrial production to meet the specific requirements of starting and closing the pump, so as to achieve the purpose of starting and eliminating water hammer with light load. However, there are some problems, such as short service life, high resistance, high energy consumption, large occupied space, especially labor intensity. With the development of science and technology, a variety of pump control valves, such as pump control valves controlled by hydraulic system, multi-function pump control valves, hydraulic butterfly valves, hydraulic automatic valves, pipe valves and so on, have gradually appeared. The appearance of these valves has promoted the development of pump control technology to a certain extent, but with the development of modern industry and the application of advanced technology, the defects of these pump control valves have gradually shown up. For example, some valves need external energy, complex structure, difficult maintenance; high technical quality of maintenance personnel; some have large flow resistance coefficient, and some are bulky, which is not conducive to the manufacture of large-caliber valves. The main problem is that the automatic control part is directly driven by the medium transported in the pipeline, so it is easy to block the control part. Plug and corrosion cause control failure, maintenance difficulties and narrow scope of use.

In view of the confusion of the valve market today, the valve products on the market can be said to be a variety of good and bad. Below the butterfly structure of the valve as a pump outlet valve must be considered when using, should also pay attention to the place, from the following four aspects to do a brief introduction and discussion:

1. The sealing form of valves

If a valve is not tightly sealed, there is no seal, then this valve is in fact a small pipe network system, there is no value as a valve must have the cut-off function. Especially the pump outlet check function of the control valve, the quality of its seal is directly linked with the normal operation of the pump unit.