The difference on FTPR and Viton + valve question

[RogerF]

I have some valves that will be placed in pipes with following service:
Lemon acid, base (type caustic soda) and biocide.

1.
In the valve data cheet, they say that PTFE shall be used as sealing material in the valve. The supplier offers VITON.
2.
It also says that the stuffing box shall consist of expanded graphite not less than 98 % purity.
The supplier offers: TFE + 25% C. Graphite

Is there anyone that knows if I can accept this or do I have to correct the valves?

Is there someone who know what the difference is between FTPR and VITON?

 

[TVP]

Viton is a tradename for a variety of fluoropolymers manufactured by DuPont Dow Elastomers. You can obtain more information about the various grades at the following website:

http://www.dupont-dow.com/Products/Viton/viton.asp

PTFE is an acronym for Polytetrafluoroethylene.
TFE is just PTFE without the P at the beginning.
I do not know what FTPR is.