Butterfly valve distributors realize the
advantages of using

this type of valve as it is not only economically
priced but is also lightweight, bi-directional and bubble-tight.
Check Valves allow medium to flow in one direction only, stop medium which flow in opposite direction .usually

these valve work automatically. Under the action of pressure of fluid which flow in one direction, the disc open. When fluid flow in

opposite direction .the fluid is cut down by the pressure of fluid and self-gravity
The check valve include swing type and lift type .

Swing check valve have an articulated mechanism and a disc which leant on surface of slop seat freely . The disc is connected with

articulated mechanism to make sure disc can reach right place on seat every time .so that disc have enough space to swing and can contact

with seat veritably in full-scale . According to the requirement , disc can be made from metal , metal embed in leather or rubber or

compound .when check valve open completely ,fluid pressure have little resistance, therefore the pressure drop through valve is relative

small.
Disc of lift check valve is on the seal face of seat .It?