I am trying to locate a 2" gas vent valve that is normally open, the ASCO Series 8214 valve specified will take 12 weeks to get, what other valve manufacturers are there for a 2" gas vent valve that I could look into.
I have had a look at the Asco valve you mention. Seems to be a very special product, and could be difficult to replace. (Others may know if there are some direct competitors). Replacement from other makes will depend on your exact application data and needs.
Question/suggestion: Are you quite sure this valve does not exist in stock somewhere in the world? If it is that urgent, jet-freight might be feasible.
Have you for instance asked direct at Ascos- supply bases for offshore North Sea? (Norway or UK?) (Australia / Asia - South America ??)