4500psi guppy tank filling 480-cc tank

Empty the guppy tank with the valve wide open without the hose and DIN assembly screwed into the valve. Unscrew the valve from the tank and remove the restrictor from the bottom of the hole where the valve threads are. It is there to block the air from rapidly flowing out of the tank. If it is still filling to slow there is a blockage in the valve above the restrictor or in the hose or quick connect. Clear any blockages by blasting it out without attaching the hose to anything with the valve wide open. If that doesn't work, contact the dealer and ask for his advice.
 
unscrewing very hard, every turn takes effort. tank is completely empty, is there a check valve holding pressure that I am missing or will I have to keep unthreading like that?




Whoa, be careful. Hopefully there's no air still left in the tank although I doubt you'd be able to loosen it with air still in the tank. Are you referring to a JB/Airtanksforsale Guppy tank? When I purchased and received mine directly from him, the valve was loose with no thread locker which is the way it should be.
 
I sounds like damaged threads on either the tank or valve. It is rare to cross thread such large thread gauged assemblies. Did you remove the restrictor from inside the valve? If it was difficult to unscrew then add silicone grease when reattaching the valve to the tank. If you purchased it new and this was the first time you removed the valve I would contact the dealer as you received a defective product. Is it filling faster without the restrictor?