There is a replacement for the Dungs gas valve for the Nor-Ray-Vac. BM gas valve manufactured by Dungs is now obsolete has now been replaced by Gas Valve SIT Sigma 848, which will be supplied within a kit of parts with the same part No. (C111513) (https://www.reznor.co.uk/product/bm-gas-valve-replacement-kit-dungs/).
Is there a replacement for the Dungs gas valve for the Nor Ray Vac?
Looking to upgrade your old heater? Look here for information on which product is the best like-for-like replacement.