Stem packing

[rocio74]

Hi all,

For pipeline ball valves (2500# gas service at 85ºC), my client wants stem packing instead of O-rings + gasket design, however, the suppliers give us the O-rings + gasket. Is it normal that the client want? What does he mean with "stem packing"?



Thank you very much,

Rocio Rodriguez

 

[gerhardl]

Yes, it is normal in the way that a number of suppliers can supply after this requirement as standard products, readily commercial available.

'Stem packing' indicates or show to a construction where several stem sealing discs ringformed are placed on top of each other in a stack and compressed from outside (from gland or thruster) to form a thight sealing aginst the stem and between the body and stem boring to outside and inside of the valve body. It is usually possible to retighten the stack from outside several times before the stack has to be changed.

This construction may or may not be combined with o-rings or separate rings on lower parts of the stem, not compressible from gland.

This stack construction may be seen as better or better suited for the service at hand.

 

[unclesyd]

Adding to the post by gerhard most valve manufacturers can supply either style packing. if some some reason they are not able to supply they style packing your client wants there are plenty of packing suppliers that can make up a packing set.

Just make sure you get your clients specific requirements especially since this is a high pressure valve.