Valve packing requirements
differ from pump packing in that the key to success is not sealing a rotating shaft, the key is resisting extrusion. This much more important in some valves than others since not all applications deal with high pressure. The similarity is that both pump and valve packing need to seal reliably.
Valve packings will often be used in a combination set. A good example is flexible graphite packing generally needs to have carbon end rings, to act as a wiper and an anti-extrusion device. We offer both high end and general service carbon packings (649), since not all applications require the better but more expensive pitch based carbon yarns (698).
Valve packings are selected using the following permitters
PH of the media being sealed
While size, type of motion, condition of the valve, application, pressure excursions, existing packing, and the type of valve also must be considered the first 3 on the list will narrow the choices significantly.
If you want your Valve packing to last the longest you will use quality materials. PTFE and Flexible Graphite hold up extremely well to Chemicals. Flexible Graphite Valve packings hold up best to heat. If your application has high pressure, wire inserted packing such as 627, 677, should be considered. Anti-extrusion rings of carbon packing are also a great idea.
For help just call us at 714-593-9780