The opening and closing part of the stop valve is a plug-shaped disc, the sealing surface is flat or conical, and the disc moves in a straight line along the center line of the fluid. The movement form of the valve rod includes lifting rod type (the valve rod is lifted and the handwheel is not lifted), and lifting rotating rod type (the handwheel rotates and lifts with the valve rod, and the nut is set on the valve body). The stop valve is only applicable to full open and full close, and adjustment and throttling are not allowed.

Low temperature valves, especially ultra-low temperature valves, have extremely low working temperature. When designing this kind of valve, in addition to following the design principles of general valves, there are some special

Special requirements.

Applicable temperature: -45~-197 applicable medium: liquid chlorine, liquid ammonia, flexible graphite filler, the temperature range is 200~870 ℃.

1、 Design requirements of dj41w low temperature stop valve

According to the service conditions, the design of low temperature valve has the following requirements:

1) The valve shall be able to work for a long time under low temperature medium and ambient temperature.

2) The valve should not become a significant heat source of the low temperature system. This is because the inflow of heat not only reduces the thermal efficiency, but also causes the internal fluid to rapidly flow if too much inflow

Evaporation, abnormal pressure rise, causing danger.

3) Low temperature medium shall not have harmful effects on handwheel operation and packing sealing performance.

4) Valve assemblies directly in contact with low-temperature media shall have explosion-proof and fire-proof structures.

5) The valve assembly working at low temperature cannot be lubricated, so structural measures need to be taken to prevent friction parts from scratching.