Helpful Hints for Installing Radiator???

[CKELLY]

Howdy,
I'm about to attempt to add a cast iron radiator, w/copper, to my hot-water system ("Fat Pipes/Skinny Pipes" thread).
I'm pretty confident with the fittings and measuring. From what I have learned so far, I will pipe toward the unions--from the supply pipe to the downstream side of the valve, and from the return pipe back to the nipple.
I assume that the two radiator nipples will be attached to the radiator beforehand, and that the valve and return pipe must be measured and piped pretty darn close to get a good connection at the unions.

I always prefer to learn from other's mistakes rather than my own, so any tips will be GREATLY appreciated. Thanks

[Grady]

(1) Don't bet on the rad coming with nipples. Maybe, but don't bank on it.
(2) You can't have too many unions or valves.
(3) Drill your holes at least 1/2" larger than you need.

[Gregory]

All the radiators I have seen utilize a 90 degree brass valve and return which have integral unions at the radiator. They screw directly into a bushing in the radiator. Plumbers usually assemble the valve and bend tight into the radiator with the unions fully tightened up and then sweat the copper pipe directly into the brass fittings. This is because the radiators aren't installed until the drywall and any flooring is completed. Trouble with this is that it is a difficult joint to make for a novice like me, upside down and close to the floor. It is easier to sweat a short piece of copper into the two fittings and assemble them to the radiator, unions tight, with the pipes sticking down through the holes in the floor. Finish the copper piping from beneath.
Dont connect the unions after making all the piping joints.