How To Install, Repair And Maintain Fluorine-lined Gate Valves?

The opening and closing part of Lined Gate Valve is the gate, and the movement direction is perpendicular to the fluid direction. The gate valve can only be fully opened and closed, and cannot be adjusted or throttled. The gate has two sealing surfaces. The two sealing surfaces of the gate valve form a wedge, and the wedge angle varies with the valve parameters. When the medium temperature is not high, it is 2°52'. The gate of the wedge gate valve can be made into a whole, called a rigid gate; it can also be made into a gate that can produce slight deformation to improve its processing performance and compensate for the deviation of the sealing surface angle during processing.

Fluorine-lined gate valves are specially used to control corrosive or highly corrosive media. The inner surface of the valve body is covered with a variety of optional fluoroplastics, which are suitable for different working temperatures and fluid pipelines. They have high strength and good corrosion resistance. The working conditions of fluorine-lined gate valves are very harsh, including toxic and harmful chemicals, highly corrosive acids, alkalis or organic solvents. Improper use will cause economic losses and serious consequences. Proper use and maintenance of the valve can extend the service life of the fluorine-lined valve and ensure the normal operation of the pipeline. Therefore, the following points should be noted during installation, maintenance and use:

1. The flange cover of the fluorine-lined gate valve shall not be opened at will. It shall not be opened at will unless it is ready to be connected to the pipeline. Due to temperature difference and foreign matter, the surface of the PTFE flange may be damaged or deformed, which will affect the seal. If the movable cover is inspected, it should be reset immediately after inspection to protect the PTFE flange surface.

2. When the fluorine-lined gate valve is connected to the pipeline, gaskets are usually not used alone, but when connected to flange surfaces of different materials (metal surfaces, etc.), appropriate gaskets should be used to protect the PTFE flange surface.

3. If the fluorine-lined gate valve leaks at high temperature during system use, the system temperature should be lowered to room temperature first, and then the cause should be found out and the valve repaired.

4. No high-temperature welding work should be performed on the fluorine-lined gate valve to avoid damage to the lining layer.

5. During installation, the flange nuts should be tightened evenly in the diagonal direction (symmetrically) with appropriate torque:

A. If the flange sealing surface leaks and the nut at the leaking position has been locked, loosen the nut at the leaking position by half a turn, then apply the same torque to the other side and lock it again.

B. If the above method still cannot prevent leakage, check whether there are concave and convex indentations and scratches on the surface of the PTFE flange, then level it with spinning paper and cloth and reconnect it.

6. Fluorine-lined gate valves should be stored in a dry and ventilated room and must not be stacked.

7. Fluorine-lined gate valves after maintenance should be installed in accordance with relevant standards.

8. When manually operating the fluorine-lined gate valve, the valve must not be forcibly opened or closed with the help of other levers.

9. When installing fluorine-lined valves with directional requirements, the flow direction of the medium should follow the direction indicated by the arrow on the valve body to ensure convenient operation and maintenance.

10. The sealing pair of the fluorine-lined valve for long-term storage should be slightly opened and separated to avoid deformation of the sealing surface under long-term pressure, thereby affecting the sealing performance and service life.