How to solve the problem of internal leakage of the valve?

How to solve the problem of internal leakage of the valve?

Valve internal leakage of the main parts of the causes and maintenance methods

Valve internal leakage, the main reason for the leakage of the sealing surface:

#1 The sealing surface grinding is not flat and can not form a close line;

#2 The valve stem and the connection of the closing member of the top center of the suspension are incorrect or worn;

#3 The valve stem bending or assembly is not correct, so the closure is skewed or not meet;

#4 The sealing surface material quality selection is not appropriate or not according to the working conditions of the valve.

Sealing surface leakage maintenance method:

#1 According to the working conditions of the correct choice of materials and type of gasket;

#2 Careful adjustment, smooth operation;

#3 Should be evenly and symmetrically screwed bolts. If necessary, torque wrenches should be used, and pre-tensioning force should meet the requirements, not too large or small. Flange and threaded connections should have a certain preload clearance;

#4 Gasket assembly should be in the right, uniform force, and gaskets are not allowed to lap, and the use of double gasket;

#5 Static sealing surface corrosion, damage processing, processing quality is not high, should be repaired, grinding, coloring inspection, so that the static sealing surface in line with the relevant requirements;

#6 The installation of gasket should pay attention to clean, sealing surface should be paraffin clear, the gasket should not fall to the ground.    

Closed pieces off to produce leakage causes:

#1 Poor operation, so that the closure piece jammed or over the upper dead center, the connection is damaged and fractured;

#2 Close the connection is not firm, loose, and fall off;

#3 The choice of connection material is not right, can not withstand the corrosion of the medium and mechanical wear and tear.

Maintenance methods:

#1 The correct operation is close the valve can not be too much force, open the valve can not exceed the upper dead center, the valve is fully open, and the handwheel should be reversed a little;

#2 The connection between the closing part and the valve stem should be firm, and there should be a stopper at the threaded connection;

#3 The fasteners used to connect the shut-off parts and the valve stem should be able to withstand the corrosion of the medium, and have a certain degree of mechanical strength and wear resistance.

Seal ring connection leakage causes:

#1 The sealing ring is not tightly rolled;

#2 Sealing ring and body welding, surfacing poor quality;

#3 Sealing ring connection threads, screws, pressure ring loosening;

#4 Sealing ring connection and corrosion.

Maintenance methods:

#1 Sealing the leakage of rolling should be injected into the adhesive and then rolling fixed;

#2 The sealing ring should be according to the welding specification to not solve the filler welding. Surfacing can not be welded when the original surfacing and processing should be removed;

#3 Remove the screws, and pressure ring cleaning, replacement of damaged parts, grind sealing and connecting seat sealing surface, and reassembly. Corrosion damage to large parts, available welding, bonding, and other methods of repair;

#4 The sealing ring connection surface is corroded. Available grinding, bonding, and other repair methods can not be repaired when the seal should be replaced.