Chief structure features and usages
- The main body of this series valve uses a casting and forging structure and has a dual-direction seal of parallel secondary semi-forced dual-sealing and the motions of both the sealing face to its due position and the tapered block to wedge-up are separated to havezero leadage come true.
- The sealing face is of a small frictional force if motion,lightly opened and closed and has a self compensation function for wearing.
- Simple structure easy to more than 10 years of long duration.
- A vacuum sealing structure is set in the filling chamber on the valve cover,which has the action of self-expanding and impacting,the joint faces are sealing with the expansive material of high strength to completely isolate the system from air.
- Two connection ways of b flange and welding,two ways to drive of heand-and eletric-operation. The valve can be used as the open & closedevice for the pipelines under the working temperatureLess than425degree centigrade and 550 degree centigrade and the working medium of water,steam or air;especially suitable to act as the vacuum isolating sealing for the system of steam turbine's considernation and vacuum negative pressure in steam power plants.
Valve ctrucure type:
Mode1 NKJ61 Vacuum isolating stop valve;Model NKZ44 and NKZ64 Vacuum isolating gate valves.
Manufacture and acceptance standard:
- Manufacture,acceptance and technical conditions per GB/T12234,GB/T12235.
2. Face-to face dimensions per GB/T12221.
3. Flange sizes per JB/T78-79,GB/T9112-9124.
Material for main parts
Body,Bonnet: 25 or WCB
Valve stem：Cr.stainless steel，25Cr2MoV
Sealing face：H: alloy steel，Y: carbide alloy
Yoke nut：Al bronze
Packing：Expanding compound graphite
Fastener：High-grade carbon steel，Cr.Mo steel