I know it's not the same thing "exactly".. but... I've seen more than a few to many brass nipples break when hanging out like that in marine applications.

possibly exchange the nipple between the valve and tank for a "CLOSE" nipple in heavy red brass. Like I said, not really the same thing but, it just "jumped" out at me hanging out there with no support on the discharge side.

Just a comment Pat.. not a critique or anything else implied!!!