Coleman o rings

Hello all.
A couple of my early dual fuel 295 and 290 have rubber o rings in the control valve instead of the graphite packing .
Firstly if anyone has the exact dimensions that would be really good, I have a rough measurement of 4.5 mm X 175 mm
Secondly and most important viton or nitrile ?
I know they're both oil and fuel resistant but is there a preference for using in Coleman lanterns.
Thanks marten

 

I believe viton is the better material of the two. As for sizes, I don't know.

 

I heard US sizes 007 and 009 for the large lanterns.
005 and 007 for the 222/226 lanterns.

 

Thanks for your replies and sorry for not replying sooner .
I could'nt decide on which size of orings so I bought three different different sizes as they were cheap enough .
Even though they all fitted on the inside diameter it was cross section or outside dimension I was getting hung up on .
Thanks marten

 

Those o-rings I’m pretty sure were fluorosilicone.
That helps with low temp operation.

 

Thanks Kevin
I have bought some now and after a lot of looking at pictures hahaha and a little reading I now know that the fluoro and viton are the same .
Fluorosilicone is the name of the product and viton a trade name

 

Marten
That is unfortunately incorrect.
Viton is the brand name of DuPonts fluorocarbon rubber

that is not the same as fluorosilicone

 

Fluorocarbon rubber (Viton):

Fluorocarbon rubber / FKM/FPM


Fluorosilicone vs Viton:

Fluorosilicone vs FKM (Viton®) for O-Rings and Seals


Tony

 

@Tony Press .. to quote Mr DP Gumby “My Brain Hurts !”

 

@podbros

Yes. I’m not too flash on polymer chemistry myself.

My shortcut rule is to buy Viton parts from The Fettlebox because they are proven to work and professionally made; and have one sheet each of 1mm, 2mm and 3mm Viton for non-standard washers.

Cheers

Tony

 

I knew I’d done something right all those yrs ago :-)

Hey ! Be careful about the word ‘sheet’ though?

Especially if you are an Italian on holiday in Malta ???

(Definitely worth a search)