There are no agents available right now to take your call. Please leave a message and we will reply by email.
or sign in with: 
On Installation: the disc of a butterfly valve is installed in the diameter direction of pipes. When it is installed, the disc should be in the closing place. The opening point is directed by the disc rotary angle. If a butterfly valve is attached with a bypass valve, the part should be opened firstly. Installation should be according to assembly instructions from manufacturer. If a butterfly valve is heavy, you should give a stable foundation.
On maintenance: the relationship between openness and fluid is that fluid changes in a linear way with the openness. If it is used to control fluid, there is a tight connection between the fluid and fluid resistance of pipes. If the valve’s caliber and form is exactly the same with another one but the pipe loss factor is different, the fluid difference of valves will be significant.
If a valve is at a position that controls much of the fluid, the back of a valve is easy to form cavitation, damaging the valve. And it is usually used in the degree of 15.And it is usually used at a degree higher than 15.
When a butterfly valve opens in medium degree, the disc centers on the bearing with a front end’s opening and the two sides present different shapes. One side the front of the disc moves in the same direction of the fluid, another against it. So, the body of one side forms a nozzle-shaped opening, another similar to orifices-shaped one. But the flow rate of the nozzle-shaped opening is largely faster than the orifices-shaped one. Besides, rubber seals usually can detach due to the negative pressure of the orifices-shaped valve.
Related recommendation:
Double Eccentric Butterfly Valve PDF ANSI High Quality Wafer Butterfly Valve
;)
;)
