I'm buying a new water heater, and quite frankly the series of connections and valves are mind boggling. What I'd like to do rather than soldier the pipes together is to go from compression to thread. I have 3/4 ID (inner diameter), 7/8 OD (outer diameter) feeding the water heater. From that point there are a series of elbows and a valve I don't trust taking the copper pipe to the water heater.
I'd like to cut them off, and put on a compression fitting and flex tube to the water heater. Is there anything wrong with this idea? Moreover, what kind of valves and adapters do I use?
Ideally, there would be a combo-valve that would go from 3/4 compression to thread, and then from a mail thread I could use a flex pipe to go right to the heater.. This valve doesn't exist, but such a setup would result in one compression rings per water line.
What does exist is compression-compression-valves, but in this configuration I'm adding two more compression rings per side of the water heater which is far from ideal. I assume this is a bad idea? I've ruled this out.
3/4 pipe → 3/4 compression female to NPT male → NPT female to NPT female valve → NPT female valve to NPT male-male coupling → NPT male-male coupling to NPT female flex pipe.
And none of these parts are carried by anyone retail store... So what's the right and easy way to do this? I've had very good luck with compression fittings.