Specifications
2.. Fire safe design
3. Ansi-static design
4. Blow-out proof design
Standards compliance
1. Design and manufacture: API 6D
2. Face-to face: ANSI B16.10
3. End connection: ANSI B16.5
4. Test and inspection: API 6D, API 598
Description
1.Fire safe design
With the valve heated in a fire application, the non-metal material such as seat sealing ring of PTFE, stem backseat gasket, gland packing and the leading gasket between body and bonnet might distintegrate or be damanged due to high temperature. Specially designed structure of auxiliary metal to metal seal is provided to effectively prevent both internal and external leakage of valve.
2. Reliable stem seal
The blow-out proof design has been adopted for the stem to ensure that even if the pressure in the body cavity is risen accidently and the packing flange becomes invalid, the stem may not be blown out by medium. The stem features the design with a back seat, being assembled from under neath.The sealing force against the back seat gets higher as the medium pressure become higher. So the reliable seal of the stem can be assured under variable medium pressure.
The traditional packing flange design has been improved to be of two piece structure, i.e.. Being as a gland flange and gland, the latter contacts thr gland flange with spherical surface. Thus, the gland remains vertical always, and is lined internally with a PTFE bush to prevent the galling against and friction between the stem, which can be also reduce the operation torque of the valve.
V type packing structure has been employed to effectively transform the force of the gland flange and the medium pressure into the sealing force against the stem.
Based on the customers' requirement, a packing tightening design may be employd to obtain more reliable stem packing seal, which is loaded by bevelling spring.
3. Ansi-static feature
The traditional packing flange design has been improved be to of two piece structure, i.e., being as a packing flange plate and a follower, the latter contacts the flange plate with spherical. Thus, the following remains vertical always, and is lined internally with a PTFE bush to prevent the galling and friction between the stem, which can be reduced the operation torque of the valve
Wrong operation prevention, the keylock with 90°of open and close positioning pad has been provided, which can be lockable as required. As the stem head, where the lever fixes, a flat is so designed that the valve opens with the indicator of open and close can be never make mistakes.
