OK, Ferg, here goes....
Although my undergraduate education was in chemical engineering I am not
certain that I should "pronounce" on the correct choice, not being an expert
on the subject. I do, however, feel competent to interpret published data,
and in this case I don't see too much difference (except price) between
nitrile and Buna-N, but McMaster-Carr's Buna-N product description tips the
balance (for me) by noting that the hose "Meets SAE J1527, Type B2 standards
for marine fuel hose."
I also did a quick Web search for SAE J1527 and found an interesting (and
brief) description of marine fuel system hoses at
http://www.tridentmarine.com/html/refers/fuelhs.html that includes these
definitions "Type A hose is fire resistant. Type B hose is not fire
resistant. Class 1 hose (for fuel distribution lines) is the most fuel
permeation resistant. Class 2 hose (for fuel fill and vent lines) may be
less fuel permeation resistant." The Buna-N offered by McMaster-Carr is
rated B2 - a Type B rating for fire resistance in the baggage bay area
probably is not too important (if you've got flames back there you have much
worse things to worry about than whether the hose will rupture) but the
Class 2 may make you reconsider. I did find a source (sort of) for SAE
J1527, Type A1 at http://www.jgbenterprises.com/static/6030.asp (with a
location not too far from you across the border near Syracuse, NY) but that
page notes that Goodyear (the manufacturer) produces large diameter sizes of
this only in rather large minimum quantities, and it is a non-stock item for
the distributor.
Another search on SAE J20R1 found links only to radiator hose applications
so if I had only these two choices I would choose the Buna-N.
I am building an XS and have yet to put fuel in the tank so I can't comment
on the suitability of hose materials from personal experience. I have used
the very short "couplings" supplied by Europa for the fuel filler connection
to the tank, and likewise for the connections at the bottom of the tank, but
I replaced the factory supplied small diameter fuel hose with Teflon lined,
stainless steel braided hose.
In re: your follow on message. What did you mean by "your address came back
and bit me?" Did your message get bounced by my server?
Best regards,
Rob Housman
A070
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Fergus Kyle
Subject: Re: Europa-List: Fuel filler
----- Original Message -----
From: "Rob Housman" <RobH@hyperion-ef.com>
Subject: RE: Europa-List: Fuel filler
> Polyurethane is a very poor choice for handling fuel. For details go to
> http://www.mcmaster.com/ and search for 5108KAC (a pdf file of
properties> of various polyurethane formulations). Read it and weep.
> PVC is even worse (5233KAC).>
> Some types of nylon (5173KAC) are good, and Teflon brand of PTFE
(5239KAC)> is the best of the plastics, but lots of luck finding either
material in a> large enough diameter, although Teflon lined hose is
available in larger> sizes (at US$43.56 per foot for 2 inch ID).
> The best choices for handling fuel and oil are the various Buna-N, and
> nitrile hoses (search for "petroleum hose") and one of these is probably>
what the Europa factory has supplied.> Best regards,
> Rob Housman> A070
Rob,
I thanked you privately, but thanks again for help.
At your suggestion, I ran across McMaster-Carr page196,
item 5285k31, 3ft of 2"ID Nitrile hose for $US20.19, and
item 5727k76, 5ft of 2"ID Buna-N hose at $US9.89 per foot.
Each claims ideal resisitance to fuel oil/gasoline and each has
a satisfactory bend radius to qualify it for a run from top centre (Classic)
to tank entry port, although I plan an aluminum horizontal plus 5 inch
upward weld for the last section into the baggage area.
Would you be willing to pronounce on either or both of these, as
to avoid the stench of diesel oil I am willing to cough up the requisite
sum? I suppose that opens the arena for any other cognosciento as well.
kind thoughts,
Ferg
A064
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