So these were originally designed as SCBA cylinders?
No they were general purpose light weight high pressure cylinders for divers and firemen alike.
The paint I don't think is original earlier versions had a lower working pressure and a smaller taper thread .715" 1.8 taper known as a standard taper and another thread version a .6 taper known as a Siebe taper for Siebe Gorman. The 3/4" BSPP parallel thread as the OP photo I think were made for Typhoon and were originally orange I think. Those earlier with the taper threads were all painted French grey with black and white quarters on the upper dome area this was our British Standard for Breathing Air.
Later to copy you lot they relaxed the rule for amateur sports divers and they could paint them any colour they liked.
I had looked as closely as I could at the valve opening. It looked similar to but not the same as a typical yolk fitting, and it looked much closer to what I thought an SCBA connector looked like.
Yes its a standard British scuba connection known a an A type pillar valve. The yoke fits most American regulators of the time US Divers Healthways Dacor AMF Voit and any thing else all fitted the bar stock machined A Type pillar Valve.
These were made from standard round CZ121 brass bar stock machined. Similar to the US Divers K valve except USD used a brass CZ120 hot brass stamping for the more complex cross flow style filler.
valve.
MDE also made later both the K type and J type cross flow filler valves the 0-ring groove was slightly different to USD and due to our beginning to increase WP and introduce the DIN 200 adaptor. Latterly some of the older American A clamps wouldn't fit the UK/EU Valves. Models like the USD Calypso the USD Aquamaster etc all had thin narrow A clamps. The Americans also thickened up the A clamps as the working pressure increased from 2200 psi to the later 3000 psi cylinders.
Maybe my USA centric view made it so that I assumed someone who wasn’t from the USA would’ve at least mentioned it… Maybe that’s on me.
There was a lot of feature creep between us. For example Luxfer Riverside California were a regular visitor back then with Luxfer Colwick Nottingham. Even some of the current Riverside Patented medical valves have British design and manufacture in them.
US Divers was another The Royal Navy Conshelf Supreme had British engineering and manufacture in them. There is a lot of history that remains confidential to this day. The strong say nothing with the understanding that in the strictest confidence that if it leaks we won't get sore we will just get even.
