Charging bottle gauge washer

[Outandabout]

Hi all
Does anybody know if the washer that sits in the recess on the end of the gauge, on the inside of the end that screws into the bottle outlet is a special type of washer or just a bog standard O ring type washer.
Hope this makes sense
I though i was doing a neighbour a favour lending him my bottle to charge his gun. He needed to change the charging hose but instead of just changing the hose he swapped the gauge for his gauge and then refitted my gauge when he was finished. Somehow he managed to loose the washer out of the end of the gauge, so when I try to charge my gun the gauge is not sealing and leaking air.
He denies losing the seal obviously
Needless to say he wont be using my bottle again.
Kevin

[eboswan]

I would have thought a standard o ring.
Have a look on bestfittings kev.

[Outandabout]

Cheers Brian
I dont know if they are encapsulated rubber or just rubber.
Kevin

[james79]

A standard nitrile o-ring should be fine but if you want to upgrade then look in to "viton" o rings. If you're only buying the odd one or two the difference in price won't break the bank and being tolerant over a wide temperature range as well as being less chemically reactive they may last longer. To be honest, however, if you've not had issues and it's purely a case of replacing one that has been helped astray stick with nitrile and save a few pence