Hello,

I got the answer from Fluid Power Ohio.
Unfortunately, they are only making business with the A14 oxygen regulator
and NOT the A20 one.

The A20 one is the one where the manual ring from the A14 has been
replaced by some kind of automatic device.

Does someone know a company able to maintain/repair an A20 oxygen
regulator?

The A20 I have has been manufactured by "The British Oxygen Co - Harlow -
England" in ....1964. This regulator is even older than...me.

Many thanks for any help.