Materials used in JET Fuel and JET Fuel System contact 3

[JanuszArtur]

I was trying to find specification of materials which are using in aircraft jet fuel systems. What kind of steel or rubber is using for tanks / seals / hoses?
Janusz

 

[Goahead]

Aircraft Integral fuel tanks, usually located in wings and other spaces, are sealed with special rubber based fuel tank sloshing sealants meeting specification
AMS-S-8802 - SEALING COMPOUND, TEMPERATURE RESISTANT, INTEGRAL FUEL TANKS AND FUEL CELL CAVITIES, HIGH ADHESION

Tubing is generally stainless type 321 for weldability without objectionable heat sensitization.

http://www.welding-advisers.com/

 

[JanuszArtur]

Interesting, but I would like to know what type of polymer has been choosen as jet fuel resistant one. I mean what is it? Silicon, Polyurethane? Maybe some PET or PTFE. I was trying to find those informations in PL knowledge base, but it is still secret.
Maybe all of polymer materials may be used in fuel system when they meets AMS-S-8802 or other standarts for materials?

321 stainless - thanks for this tip.
Some parts in engine has contact with fuel - eg piston usually made aluminium alloy. The same materials are using in engines for planes?
Greets, Janusz Artur

 

[dalcazar]

some general aviation aircraft and many WWII era planes have or had bladder fuel tanks made of some form of rubber, this allows them to contract and eliminate head space, fully aerobatic planes need this capability to avoid fuel draining away from the suction point.

Polyethylene is not approved for holding fuels since it will fail at temperatures around 140 degrees F

As for other kinds, the Concorde was fitted with a special kevlar-rubber composite on the lower half of the fuel tanks above the landing gear after the paris takeoff accident, this was for armor and not for regular lining, but it goes to show these materials are fuel resistant

http://www.tms.org/pubs/journals/JOM/9807/Rath-9807.html

that link might be useful, scroll down to where it says flouritanted network polymers.

 

[btrueblood]

Nitrile rubber used to be the standard for O-rings and seals in fuel systems (still okay for JP-3 thru JP-8). Fluorinated rubbers (Viton, Kel-F, etc. going by the generic term FKM or fluorinated elastomers) can stand up to higher temperatures and more agressive fuels such as JP-9 and JP-10. Parker recommends FKM for JET-A service, and rates nitrile as only "fair" for this fuel.

Just about any steel (and frankly, any common metal - e.g. brass, aluminum) is okay for use in fuel systems, with the caveat that some fuels have fairly corrosive contaminants and/or constituents. Sulfur contaminants especially will corrode copper-base alloys.