Proper locations of suction Tee, valve, and bleeder placement on older hot water cast iron radiator

Lambini

My HVAC guy will be reattaching our hot water cast iron radiator to the line after we've sandblasted and painted it last fall. We have a single hot water line that goes into one lower end of the radiator and out the opposite lower end. He wants to double-check what the proper placement of the bleeder, the adjustment valve, and the suction tee in relation to each other. The flow of the hot water is from left to right. Thanks!

Ironman

Suction Tee?? I don’t know what that is.

Are you referring to a Monoflo Tee below the floor?

Lambini

Hello Ironman, it is below the floor. I don't know if it is a Monoflo Tee, it is old, probably from the 40's or 50's. I'm assuming it creates a venturi effect and pulls water from the radiator, am I correct? If so, where should the bleeder valve and above floor flow adjustment valves be located in relation to the Tee? Thanks for your help.

Ironman

Here’s a great article on diverter tee systems:

https://heatinghelp.com/systems-help-center/diverter-tee-q-and-a/

EdTheHeaterMan

@Lambini, I am making an assumption that you did not mark the radiators in any way to remember which room or which direction they were before you removed them.

This may be a problem. You see, the union nut that attaches to the valve and return bend are not standard. It is possible that the union of the return bend is different than the union on the supply side of the radiator. If you try to match up bedroom A radiator in Bedroom B they may not match and if you try to place the radiator in the correct place with the sides reversed, they may not match.

Chances are that when the system was built, all the valves and all the return bends were from the same manufacturer and you will be just fine, even if you get the same size radiator in the wrong room. Let's hope so! I have installed complete systems in the past and asked for 20 of the same fitting, valve or union to complete the job. When I get to the job, I find that 7 have been backordered and I get a different brand to finish the job. It has happen in the 1950s too.

If your start to play musical radiators, be careful not to scratch the floor with all the moving of heavy cast iron blobs of heat emitter. Sometimes it is easier to just purchase new valves and return bends.

As far as bleeding hot water radiators, the bleeder location does not matter. Left or right is fine as long as it is at the top. That is where the air goes when you fill them with water. The TOP!

Lambini

Thanks Ironman, that's a fantastic article on diverter tees! And thank you EdTheHeaterMan, yes, you are correct, we are playing musical radiators with a chunk from one and a chunk from another (same make/model however).