Corny kegs... again

[jambop]

Hi I bought a reconditioned keg and to be honest it is nearly as good from the outside as a new keg... should have taken advice and saved may self 100€ on the two new ones I bought! However something odd about the gas and beer posts they have two o-rings rather than one?? Is that normal?
edit
I think I have the answer. Is it possible that the keg was originally pin lock and has had now posts fitted which are a ball lock conversion that requires two o rings?

 

[JockyBrewer]

Some of the converted pin lock kegs have posts with two o-rings. No idea why, but it is ‘normal’.

They can be tough to get the disconnect on to thanks to the extra o-ring. It helps if you wipe a little silicone grease on the o-rings.

 

[Rodcx500z]

I have 5 and 2 have double o rings