Originally Posted by Hardstuff
Can I unscrew the T needle valve assembly as 1 unit while mounted on the tank? The reason I ask this is I am not sure if I have a bench vise or not. If there will be a high risk of damage to the tank or regulator I could take it to a friends house instead.
I am not sure what you are referring to; the needle valve is already one unit from what I can see in your (blurry) photograph.
A bench vise is the easiest way to do it. You can probably do it without one, but it will be harder.
Originally Posted by Bettatail
How about rotate the regulator to this position:
you can take out the NPT to air hose connector, connect a solenoid to the so call "needle valve", then a real usable needle valve or metering valve to the solenoid.
You can do this too, but I would prefer to remove the needle valve that is currently on there for a cleaner look in the end.