How to deal with the failure of sealing performance of gate valves

The failure of the sealing performance of gate valves can cause medium leakage, affect system operation, and pose safety hazards. The following are four ways to address this issue:

Fault diagnosis: Firstly, check the sealing surface for wear, scratches, corrosion, etc., which can lead to seal failure in severe cases; The second is to check the clearance between the valve seat and the valve disc. If it is too large, it is easy to leak, and if it is too small, it will affect the opening and closing. It can be checked with measuring tools; Thirdly, check the sealing material to confirm whether it is aging, deteriorating, or damaged. Incompatibility will accelerate its damage; The fourth is to check the operating mechanism. If it is not flexible or faulty, it will affect the sealing. It is necessary to check for blockages and wear and deal with them.

Emergency response: If the sealing of the gate valve is found to be ineffective, the upstream and downstream valves should be immediately closed, and attention should be paid to the operation sequence and strength; Set up warning signs at the leakage site and take protective measures according to the properties of the medium; Collect leaked media in suitable containers to prevent environmental pollution, and handle flammable, explosive, and toxic media according to safety regulations.

Repair measures: Slight wear and scratches on the sealing surface can be repaired by grinding, using appropriate tools and abrasives, and strict inspection after grinding; Damaged sealing materials should be replaced in a timely manner, and materials that are compatible with the medium and have good performance should be selected; Serious defects or damages to the valve seat and disc require repair or replacement. Minor defects can be repaired by welding or surfacing, while major defects or irreparable damages require replacement; Operating mechanism malfunction requires adjustment and maintenance. If the handwheel is not flexible, it can be cleaned and lubricated. If the gear is stuck, it can be inspected and replaced.

Preventive maintenance: Establish a regular inspection system to comprehensively inspect the sealing performance and operating mechanism of gate valves, and determine the inspection cycle based on usage; Strengthen operator training to familiarize them with operating procedures and avoid improper operation; Regularly add lubricating oil to the gate valve operating mechanism and transmission components; Regularly replace the sealing material based on its service life and condition to ensure the sealing performance of the gate valve.