>I worked for an aerial recreational vehicle manufacturer
>until the early 1990's. For the fuel lines on our
>engine systems, we used transparent tubing. I believe it
>was made specifically as fuel line. The product was named
>"Tygon" and came in different ID's. The only things about
>it I remember being a problem were: Fuel in certain areas
>of the country contained different additives which could
>cause the tubing to swell and slip off a fitting (we took
>care of that by safety wiring it). If my memory serves me
>correctly, they had other fomulations that reportedly
>were not as effected by fuel additives.
>The other problem was, one had to keep an eye on the lines
>as they became hard with age (as the fuel wicked the oils
>out of the tubing) and would crack or break.
>Changing them on a regular basis was part of the "normal"
>maintenance for the vehicle.
>Hope this helps and if anyone wants more info, I'll try to
>get more info from one of the guys who designed the
>engine system.
>
>
>Art Mack
>76 MGB (under resto.)
Hmm,
Tygon tubing for fuel line use?
Tygon is a clear plastic (PVC) tubing that resists fruit acids,
lye, achohol, greases, and oils. Autoclavable. Can be used
for temps from -27F to +212F (-33C to 100C). (From the
Fisher Scientific catalog.)
Clear PVC tubing is a general purpose, clear, flexable plastic
tubing for transmission of fluids, gases, and some solids. Superior
resistance to strong acids, gasoline, oils in general, alcohol, and
hydrocarbons. (Note: brittle temp = -40C or -40F). (small parts
catalog).
This discription indicates that it is suitable.
Other tubing products:
Nalgene:
Nalgene is a transparent, nontoxic, and noncontaminating,
autoclavable tubing. Made from the highest grade of resins
and plasticizers. Resists hardening, discoloration, and a wide
range of chemicals. (From Fisher Scientific Catalog).
Teflon:
Teflon tubing is useful for a wide variety of laboratory applications.
Heat resistant to 500F (260C). Non-absorband to water and uneffected
by acids and alkalies. Also available in a heat shrinkable variety.
(small parts catalog). No mention of brittle point.
Viton tubing:
This is a non clear tubing! but, it is a high performance synthetic rubber.
It offers the widest range of fluid and chemical resistance of any
commercial rubber. Excellent resistance to oils, fuels,
lubricants and most acids. Applications include fuel and oil lines,
cable jacketing, solvents, chemical lines, etc. etc. Brittle temp -30F, -34C
(small parts catalog).
NOTE: I have used this stuff and it is indeed inpervious to chemical
attack. However it is not clear.
Polyurethane:
Polyurethane tubing is clear, flexible, resilient. Excellent
resistance to oils,
grease and fuels. Wide temp range -60 to 220F (-51 to 104C). Much
more resistant to pressure or vacuum applications than PVC or rubber.
Brittle temp -60F. (small parts catalog)
**This looks like it might be a good compromise.
Nylon:
Nylon is resistant to solvents, alkalies, oils, greases, petrolium products,
fungus and molds. Generally good resistance to dilute acids but
testing suggested. Temp range: -90F to 212F.
Polyethylene:
Chemically inert. -76F to 140F.
Whew. OK. However still don't know which is best.
I'd suspect naglene or polyurethane, or teflon.
-Dave
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