I think you mean Viton. It is one of the materials that can survive BioDiesel, SVO and WVO. They have Hose and O-rings made of that material
There was a thread about 2 weeks ago where a member was asking if he could use "Fuel Injection Hose" for Biodiesel use. See if you can find that thread. The conclusion was that tie inside was lined by a material that is similar to Viton. Also the GoodYear Hose site listed it as sutiable for Biodiesel. All that info is in the other thread.

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84 300D, 82 Volvo 244Gl Diesel