High-pressure power station Y-type stop valve

I. Introduction:

    The J965Y high-pressure power station Y-type stop valve belongs to the forced-seal valve type. Therefore, when the valve is closed, pressure must be applied to the disc to force the sealing surface to prevent leakage. When the medium enters the valve from below the disc, the resistance that the operating force needs to overcome is the friction between the stem and the packing, as well as the thrust generated by the pressure of the medium. The force required to close the valve is greater than that required to open it, so the diameter of the stem must be large; otherwise, the stem may bend due to excessive force. In recent years, since the emergence of self-sealing valves, the medium flow direction of stop valves has been changed to enter the valve cavity from above the disc. At this time, under the action of medium pressure, the force required to close the valve is small, while the force required to open the valve is large, so the diameter of the stem can be reduced accordingly. At the same time, under the action of the medium, this type of valve is also more tightly sealed. China's "Three Modernizations for Valves" once stipulated that the flow direction of stop valves must be from top to bottom. This valve should be installed horizontally. When the stop valve is fully opened, when the opening height of the disc reaches 25% to 30% of the nominal diameter, the flow reaches its maximum, indicating that the valve has reached the fully open position. Therefore, the fully open position of the stop valve is determined by the stroke of the disc.

II. Structural Features:
1. Adopts a pressure self-tightening sealing structure, with a retaining plate to pre-tighten the sealing ring. The sealing ring is made of formed flexible graphite. The higher the medium pressure, the better the sealing performance.
2. Adopts an impact-type handwheel to reduce operating force.
3. The valve seat is embedded in the valve body with flat sealing. Both the sealing surfaces of the disc and valve seat are plasma-sprayed with cobalt-based hard alloy, which is wear-resistant and scratch-resistant. The stem surface is subjected to corrosion-resistant nitriding treatment, and the medium flows in from below the disc.

III. Application Specifications:
1. Design and manufacture in accordance with JB 3595.
2. Structural length shall be in accordance with JB 3595 or as required by the user.
3. Connection ends shall be in accordance with JB 3595 or as required by the user.
4. Valve inspection and testing shall be in accordance with JB 3595.

IV. Parts Materials: