The opening and closing of the GATE VALVES  is blocked, inflexible or unable to open and close normally, or even unable to continue to open and close, mainly due to the jam between the valve stem and other parts, mainly the jam between the valve stem and the packing. Generally

The packing gland is deflected and hits the valve stem

Treatment method: install correctly

Packing is installed incorrectly or is too tight

Treatment method: pre-tighten the filler and loosen the filler appropriately.

Stem and packing gland bite

Treatment method: replace or repair.

Bites or bites between parts

Treatment method: Lubricate the valve stem appropriately.

Scratches on the valve sealing surface, bite scratches on the light column of the valve stem and bite scratches on the threaded portion of the valve stem, etc. After the sealing surface is ground, there are abrasive grains embedded in the sealing surface, but it is not cleaned, causing the sealing surface to be scratched; after some use, the abrasive grains are discharged under the erosion of the medium and stick to the sealing surface. The valve is opened and closed. Cause abrasions.

Treatment method: Use abrasives reasonably, and clean the sealing surface after grinding.

The dirt or welding slag in the medium is not cleaned up, causing scratches.

Treatment method: clean again.

GATE VALVES stem rubs against the packing press sleeve and packing pad. The medium containing boron in the medium will crystallize to form hard particles after it is discharged. When the packing contacts the valve stem, the surface of the valve stem will be strained when switching.

Treatment method: correct installation, adjust the clearance of parts and improve the surface hardness of the valve stem. The trapezoidal thread is contaminated and the lubrication condition is poor; the valve stem and related parts are deformed

Treatment method: remove the stolen goods, apply lubricant to the high temperature copper valve in time; correct the deformed parts.