RE: Neoprene, Tygon, and Viton UV Resistance
I have been using Tygon for years. I change it every year due to stiffness. This year I am using all 3, Neoprene, a Viton equivalent, and Tygon. I am now worried about the Neoprene after reading the above. Viton is a brand name, btw.
Neoprene is extremely flexible, almost too flexible for my tank. I had to extend my brass tubing deep into the tank to keep the clunk from dropping forward.
The Flouroelastomer hose (Viton equivalent) I bought from Duda Diesel is not very flexible and will not work in the tank. I use it outside. There are different grades of Viton or Vitube that have different stiffness. The stuff I bought from Duda says it is 65A, Grade A at $2.75 per foot. There is apparently a more flexible Vitube: Type B, 60A. The 60 is the durometer gage, lower being more flexible. If you search around the net you will get more information. [link=http://www.mcmaster.com/#viton-fluoroelastomer-tubing/=83c457]Mcmaster Carr[/link] sells it for like $3.79 per foot. I will try this next.