I acquired a set of doubles recently. The cylinders have passed hydro, so I need to put it all back together now. I've never had to touch a valve before.
It looks dirt simple, but I'm curious if the little black o-ring looking things in the photos are in fact o-rings. They are squashed so flat and so hardened and broken-down, that I cannot tell if they are o-rings or some other specialty seal. Also, what is the purpose of the small nylon washers, and is it necessary to replace them? They look fine, do they have any sealing purpose?
Any help is sourcing these parts, other than a best guess at the hardware store?