The structure of the decision of the valve body and the valve body and pipeline, body and bonnet connection, manufacturing method, several casting, forging, forge welding cast welding and tube sheet welding. Forging valve body has a large diameter direction, cast body gradually to the development of small-caliber. Any kind of valve body to forging, casting, according to user requirements, as well as factory-owned manufacturing means.

Gate valve flow channel can be divided into full bore and two necking. Flow channel aperture valve nominal diameter, is basically the same as the full bore type; circulation aperture ratio valve nominal small as necking-in. Necking shape uniform necking and fees uniform necking two. The flow channel was cone tubular that is a non-uniform necking Such valves inlet end of the aperture is basically the same as the nominal diameter, and then gradually reduced, reduced to a minimum to a seat at the.

A reduced-diameter flow path (either cone tubular non-uniform diameter reduction or uniform diameter reduction), the advantages are the same specifications of the valve, can reduce the size of the ram, the hoisting force and torque; drawback is that the flow resistance increases, pressure drop and energy consumption increases, so should not be too much shrinkage. For cone tubular necking, seat diameter than nominal diameter, usually 0.8 to 0.95. Nominal diameter less than 250mm necking valve inside diameter of the valve seat is generally higher than the nominal diameter reduce a file; nominal diameter equal to or greater than 300mm reduced bore valves inside diameter of the valve seat is generally higher than the nominal diameter lower second gear.