ASTM material spec for PTFE v-ring packing

[smalld]

Help,
New to the valve industry and I am creating a drawing for a packing set. All I Know is the current material used is a white native PTFE. I would like to ad an ASTM material spec to the print to ensure the right stuff.

Thanks

 

[smalld]

Sorry or a asme spec for the PTFE packing

 

[JimCasey]

I don't think there is an ASME spec for the packing. The pervasive practice in the industry is to call out the spec number from the packing manufacturer used, unless the valve manufacturer just wants to keep the packing spec proprietary.

Example: Masoneilan (I do not work for them) identifies their packing as Crane 285K. This particular packing is a square-cross-section aramid fiber (Kevlar) skive-cut ring with a TFE overbraid. For an all-braided TFE ring, they call out Chesterton 324. Other packings are just called out as TFE V-ring or Grafoil.

 

[belowzero]

If you look at

http://global.ihs.com/search_res.cfm?RID=Z56&ocid=sdo-astm-search

(which is clearer than the ASTM site), and search for PTFE you find a number of standards for 'Virgin' PTFE Tube (which I summise you are using). There are also PTFE composites within the ASTM List.
I am afraid that is as close as a standard as you will get, but at least that controls the material if not the design.
B

 

[NGiLuzzu]

smalld,
please take a look at thread408-163021 within this Forum: the fantastic world of commercial polymers is always an... "undiscovered country" ;-)

Regards, 'NGL

 

[belowzero]

With reference to that thread I'd like to add that the 'Jamesbury' EXTREME PTFE material breaks the normal PTFE barriers working in temperatures where PEEK would normally be chosen.
In fact PEEK was used as a component within a chevron packing set to stop lower extrusion.
B