Reason：
1. Seal ring rolling is not strict.
2. Sealing ring and body welding, welding quality is poor.
3. Sealing ring connection screw, screw, pressure ring loose.
4. Sealing ring connection and corrosion.
Maintenance method:
1. Sealing ring rolling pressure leak should note adhesive and then rolling fixed.
2. Sealing ring should be based on the application of welding specification to repair welding. Surfacing and processing should be removed in surfacing welding process.
3. Remove the screws, ring pressure cleaning, replacement of damaged parts, grinding sealing and connecting seat sealing surface, re assembly. A large part of the corrosion damage, the use of welding, bonding and other methods to repair.
4. Sealing ring connection surface is corroded, can be used for grinding, bonding and other methods of repair, can not be repaired when the sealing ring should be replaced.
