why are paper seals used in oil systems

[ronnie barker]

hi guys,
why are paper seals used in stead of rubber seals when mating components to a drive plate? i.e. oil pump on gazelle to the accesories?

[Whirlygig]

Doesn't oil rot/dissolve rubber?

Cheers

Whirls

[WOMBAT45]

Is someone doing his A2?

[ShyTorque]

No, I think someone's bought a Gazelle! :)

[Newforest2]

No, I think someone's bought a Gazelle!

With an oil leak?:ugh:

[ShyTorque]

This perhaps explains:

(He's got at least 30 of them sitting in a hangar)

http://www.pprune.org/rotorheads/393083-anti-flail-devices.html

[nodrama]

I would refer to it as a gasket, rather than a seal.

This definition from wikipedia might help:


A gasket is a mechanical seal (http://en.wikipedia.org/wiki/Seal_(mechanical)) that fills the space between two mating surfaces, generally to prevent leakage from or into the joined objects while under compression (http://en.wikipedia.org/wiki/Physical_compression). Gaskets save money by allowing "less-than-perfect" mating surfaces on machine parts which can use a gasket to fill irregularities.

[dieseldo]

Most so called rubber seals are made from man made oil resistant material. This is why the majority no longer have a shelve life.

Natural rubber seals are a rarity.

Whether they are called seal or gaskets seems to depend on the manufacturers terminology.

Common english useage for a seal between two flat faces would be a gasket.

Gaskets for aviation use are commonly "rubber", paper, cork and sometimes metalised fibre.

The use is largely determined by temperature and whether the joint is pressurised or not.

For instance the Puma fuel boost pumps use a "rubber" gasket the 365 pumps use a cork gasket. The fuel is the same and the pumps the same yet the manufacturer chose different material. Who knows why!!!!!!!

[spinwing]

Mmmmm ...

As per 'nodreama' above ....

Also paper gaskets may be used to reduce the possibility of 'galvanic corrosion' occurring where dissimilar metals may be faced together ie where an aluminium alloy pump might be bolted to a magnesium alloy g'box casing ..... using a paper gasket may also be a method to reduce water or other liquids getting in between mated joins and thereby promoting corrosion or the 'fretting' of the components.



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