1. Leakage of bonnet suppression hole
The bonnets of some valves have pressure holes for pressure test by the manufacturer, which may cause water leakage during use. The main reason is that the suppression hole is not tight.
Solution: Fasten it from the beginning, perhaps remove the bolt of the suppression hole, take out the copper pad inside, and then polish the screw hole to clean the belt and fix it with electric welding.
2. Leakage at the junction of valve body and bonnet
Inadequate tightening force or uneven tightening of the bolts at the flange joint makes the flange skew, resulting in leakage at the joint between the valve body and the bonnet, or the joint surface of the valve body and the bonnet is damaged, the flange gasket is damaged, etc. Doubts form leaks at their connections.
Solution: The best choice for flange fastening is the diagonal fastening of the flange; pay attention to the maintenance of the joint surface when using it; choose a better quality gasket. If the gasket cannot adjust the contact surface, the contact surface can be reprocessed.
3. Leakage of stuffing box
The packing is not compatible with the corrosion, temperature and pressure of the working medium, wrong packing method, poor surface finish of the valve stem, corrosion, rust, or packing for a long time, or even aging, these questions are caused by the stuffing box The reason for leakage.
Treatment plan: choose accurate packing method; carry out packing according to accurate method; choose valve stem whose surface finish reaches the requirement; adopt corresponding protective measures to prevent rust. If rust is found, replace it in time.
