Can we use PTFE Gland packing in Fugitive Emission Control design (Globe Valves). I heard PTFE will fail during thermal cycle tests as prescribed in ISO 15848?

Also is double packing arrangement is a must for FE design?

Not having checked all relevant standards and tests, I believe there is more a question of if a certain constructed valve with a certain given sealing material and sealing construction will withstand a certain specific test and perform to a certain test-grade or not.

It is in my opinion not possible to answer your question on a general basis.

The only way to prove something like this will have to be either using a valve that has undergone an actual certified test, or is guaranteed by producer to be valid within certain parameters, if this is accepted, or to actually perform a test.

ISO 15848 certification is one thing but as the reason for FE is to exclude noxious and harmfull chemicals the use of Graphite has to be questioned where medias exist that readily leach and errode graphite. Phosphoric acid comes to mind as an example.
 PTFE packing is the only suitable material in this type of use and the design temperature of the chemical resistant materials is usually a large part of the medias process design.
 In this case the Standard is taken as a marker but the various temperatures which would compromise the materials are taken out, although the ISO standard cannot be used to certify this material the manufacturer can show that the same testing has been applied in principle, cycles, leak rates etc.
Calling up ISO 15848 as a standard without understanding the plant and medias involved is not practical.

MORE NEWS