Copper valve seat
In the valve can remove the facial parts, designed to support the valve core seated position, and constitute a seal deputy. General copper seat diameter as the valve maximum circulation diameter. For example butterfly valve seat material is very wide, all kinds of rubber, plastic, metal materials can be used as the seat material, ball valve's main function is to cut off or on ducted fluid channel. The working principle of ball valve by drive in the valve rod top put some torque to the sphere, make its rotate 90 °, complete open or close the valve action. Ball valve and valve seat sealing principle according to its structure and different, commonly used seat structure can be divided into fixed seat floating spheres and floating valve seat fixed sphere two kinds big. When the seat fixed sphere floating, in fluid pressure sphere under the action of the fluid flow direction produce displacement, make it and after the valve seat sealing and more closely contact, namely in the seal on the surface of the specific pressure increase, form single seal, at the same time, the valve seat sealing surface before than pressure decreases, often does not guarantee seal. When the seat floating spheres fixed, fluid pressure can't make sphere produced displacement, but the seat with the aid of spring or fluid thrust pressure to the sphere, the establishment of seal specific pressure.