Control Plug Valves can rotate 90° to connect or cut the medium. Body cavity with grooves and convex edges structure design can fix sleeve effectively, which can meet special application need. The design can protect valves avoid from the sleeve and plug rotation at the same time which may cause the valve to break when close. Sleeve material uses Dupont PTFE, it has good strength, small friction factor, small torque, reliable seals, long service life, etc. advantage.
Bearing strong corrosion resistance as well as high temperature and high-pressure resistance, the Control plug valves of Weidouli is an ideal valve for controlling medium in in petroleum, chemical, and smelting industries which are easy to crystallize and contain granular impurities and harsh working conditions.
Large-size plug valves manufactured according to the ordinary structure will face internal sealing and middle sealing leakage after a period of use. To solve this problem, we use our self-developed trunnion type double gland plug valve to manufacture a large-size plug valve.
Plug trunnion structure
In high temperature and high pressure, the plug trunnion structure does not offset or extrude the sealing sleeve (valve seat), and the cock is always in the central shaft, which effectively solves the sealing leakage of large size valves caused by the sweeping of its sealing sleeve.
Adjust sealing function by the double-gland structure
Double-gland, packing adjust gland, and plug adjust grand, can adjust the packing and sealing separately on-line to ensure the reliability of packing and sealing, and meanwhile can reduce the operating torque to make the switch portable and easy to operate.
Multiple -sealing structure
First layer: Sealing sleeve; sealing sleeve employs import modified PTFE as material, which has temperature resistance up to 260 ℃ and owns the advantages of high strength, low friction coefficient, small opening and closing torque, reliable sealing, long service life, etc.
Second layer: Wedge type pressure sealing gasket; wedge type pressure sealing gasket, made of modified PTEE, can prevent high pressure and leakage of the medium when the pressure of pipeline rises abnormally all of a sudden.
Third layer：Wedge type packing or flexible graphite packing seal.
Wedge type packing seal can effectively prevent packing pressure point displacement and packing seal failure caused by non-uniformity. Flexible graphite packing has the advantages of high temperature and high-pressure resistance and fire protection.
Three reliable sealing structures meet the requirements of API607 for fire and static protection.
Packing box at the bonnet
A packing box is added between the valve body and bonnet, so the contact between the medium and the valve bonnet is completely interrupted, which allows the material of the valve cover to be changed from the special material to the stainless steel, which saves the special material and reduces the cost.
Spring loaded to compensate seal automatically
The belleville spring is used to load the connecting bolt between the packing and plug adjust gland to prevent an abnormal change of pressure and temperature in the pipeline. The belleville spring can automatically compensate for and protective sealing.
Add a surface bearing under the cock cover to reduce the operating torque and light switch, which can effectively improve overlarge torque and overweight operation of the plug valve.
Put spiral wound gasket in the concave groove of the valve body. Sealing is reliable since gaskets remain elastic for a long time.