plane guy wrote:
> 
> Hey gang
>      Got some stuff from US plastices 1-800-537-9724 right here in town
> ...40 cents a foot and they give you all the specs for it if requested
> ,good for gas fuel , oil ,and a bunch of other stuff.
>                       Dave R

From: "Scott Perkins" <2scott@bellsouth.net>

Please Ask Mr US PLASTIC whether his tubing is:

Vinyl
PVC
CPVC
Nylon
Polyethelene
Silicone
Neoprene
PFA resin
Floropolymer resin
PTFE
FEP
with or without plasticizers

I'm sure you can see if it is reinforced or not.
It will have writing on it if it is pressure rated.

Has it been tested to any ISO or Mil Spec guidelines ?

The question before us is I think  . . . What is the best?

We have these primary considerations:

-high temperature or not ?
-high abrasion or not ?
-high cold temperature flexibility or not?
-resistance to UV radiation degradation
-resistance to swelling and hardening caused by hydrocarbons

"Tygon" is a trademark name for a series of industrial tubing made by
Norton Performance Plastics Corp.  In most cases they do not divulge the
chemical makeup of their various proprietary tubeing models.

A strong preference for any of the above attributes will negate high
performance in the other areas in the selection of the optimum tube
composition.  For instance, the highest UV rated tube does not do well
in the cold flex or long term hydrocarbon imersion area.

However, to avoid making a long story longer, in non UV intense, non hot
( > 300 degree F., non cold < 20 degree F, non high flex, non exposed to
UV environment, TYGON formulation # f-4040-A is the recommended choice
for hydrocarbon fluid transmission.  Expected life
of 12 15 years in moderate environment of exposure to hydrocarbons.
( Basically used by lawnmower manufacturers  etc. )

It has a piss yellow color in case of possible confusion with other of their
products.   So the Tygon line sold by Mark Smith should be piss yellow
unless another performance attribute has been targeted.

It should be noted that the HIGH UV resistant line looks like automotive
fuel line.  Black and very thick walls.  I have a friend that has elected
to use automotive reinforced fuel line.  

This has been the most anal retentive thing I have ever written.
Please accept my apologies.  I should have just said . . . .

"Get the piss yellow tygon stuff"  leave the rest alone.  And at Home Depot
where it says for each type of tubing "suitable for fuel line use" add for 
"a few months only".
 

My McMaster-Carr catalog has "Tygon" and "Tygothane", it gives Tygothane
better marks for a few properties. (example, cold temp. flexibility) and
it's cheaper than Tygon.

http://www.mcmaster-carr.com/

b.w.



Scott Perkins wrote:
> What is the Tygon part number or "formulation number" on the spool?
> Let's see what Norton Plastics say it is best for ?
> 
> When you say it gets brown in a year is it subjected to UV that causes that?  Do
> you have any that was covered etc. that did not turn brown?  Interesting. It
> does appear that "pretty floppy" implys
> a non hardening compound as specified in the presense of hydrocarbons.