Product overview

Chief structure features and usages

1. 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 have zero lead age come true.

2. The sealing face is of a small frictional force if motion,lightly opened and closed and has a self compensation function for wearing.

3. Simple structure easy to more than 10 years of long duration.

4. 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.

5. 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 & close device for the pipelines under the working temperature Less 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:

1. 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

Disc: Cr.stainless steel, 12Cr1MoVA.

Sealing face: H: alloy steel, Y: carbide alloy

Yoke nut: Al bronze

Packing: Expanding compound graphite

Fastener: High-grade carbon steel, Cr.Mo steel