The working principle of the high-pressure ball valve: the ball and seat sealing ring are made of metal materials, and the sealing specific pressure is very large; when the channel is closed, under the high temperature and high pressure medium, the wedge-shaped head of the valve stem makes the sphere expand and the valve seat is compressed to achieve a seal. Loosen the wedge-shaped head before rotating the ball, and the ball will return to its original shape, so that there is a small gap between the ball and the valve seat, which can reduce the friction of the sealing surface and the operating torque. The ball rotates around the valve body line to achieve the purpose of opening and closing.
The high pressure ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline.
The high-pressure ball valve must first find out that the upstream and downstream pipelines of the ball valve have been relieved of pressure before proceeding with disassembly and replacement steps:
1. Ensure that the parts are clean and free of impurities before assembly;
2. Do not soak non-metal parts for a long time, otherwise it will rust;
3. The bolts on the flange must be tightened symmetrically, gradually and evenly during assembly.
4. Special tools should be used when removing the sealing ring to avoid damage to the sealing surface of the parts;
5. Use grease to lubricate. Grease should be compatible with ball valve metal materials, rubber parts, plastic parts and working medium;
6. Metal chips, fibers, grease, dust, etc. should not be allowed to contaminate, adhere or stay on the surface of the parts or enter the cavity during assembly;
7. Whether there are impurities or welding slag in the pipeline, the pipeline must be purged.
After installation, the valve is opened and closed several times to ensure flexible action, uniform force, and normal operation; according to the design requirements of pipeline pressure, the sealing performance of the joint surface of the high-pressure ball valve and the pipeline flange is tested after pressure is passed.