I have a Draught Technologies regulator there is a black rubber ring integral to the bottle connection, do I need another washer/ Onring? I've tried contacting the manufacturer but no response...
nope, your good to go. To check for leaks, turn the gas out off, and then turn the tank off, and see if it holds pressure.
You can get replacements if it's leaking what you have is a Quad-seal (an o-ring that seals on 2 surfaces instead of 1)
Is the quad ring a standard size
Yes same as a Tiprite