The Solutions To The Leakage Of The Control Valve (Regulating Valve)--II

The Solutions To The Leakage Of The Control Valve (Regulating Valve)--II

05 Adopt lens pad sealing method

For the sealing of the upper and lower covers, the sealing of the valve seat and the upper and lower valve bodies. If it is a flat seal, under high temperature and high pressure, the sealing performance is poor, causing leakage, you can switch to the lens gasket to seal, and satisfactory results can be obtained.

06 Replace the gasket

So far, most of the sealing gaskets still use asbestos plates. Under high temperature, the sealing performance is poor and the service life is short, causing leakage. In this case, spiral wound gaskets, "O" rings, etc. can be used instead, and many factories have now adopted them.

07 Twist bolts symmetrically and adopt thin gasket sealing method

In the "O"-ring sealed control valve structure, when thick gaskets with large deformations (such as winding sheets) are used, if the compression is asymmetrical and the force is asymmetrical, the seal is likely to be damaged, tilted and deformed. Seriously affect the sealing performance.

Therefore, in the maintenance and assembly of such valves, the compression bolts must be tightened symmetrically (note that they cannot be tightened at one time). It would be better if the thick gasket can be changed to a thin gasket, which is easy to reduce the inclination and ensure sealing.

08 Increase the width of the sealing surface to prevent the plate valve core from jumping when it is closed and reduce its leakage

Flat spool (such as the valve plug of two-position valve and sleeve valve), there is no guiding and guiding surface in the valve seat, because the valve core is subjected to lateral force when the valve is working, and it flows out from the inflow side. On the other hand, the larger the spool fit gap, the more serious this unilateral phenomenon, plus the deformation, misalignment, or the small chamfer of the spool sealing surface (usually a 30° chamfer for guidance), so that the spool seal will occur when it is close to closing The chamfered end face is placed on the sealing surface of the valve seat, causing the valve core to jump when it is closed, or even fail to close at all, which greatly increases the valve leakage.

The simplest and most effective solution is to increase the size of the valve core sealing surface, so that the minimum diameter of the valve core end surface is 1～5mm smaller than the valve seat diameter, and there is enough guiding effect to ensure that the valve core is guided into the valve seat and maintained Good sealing surface contact.