Are these monoflo tees?

roddyguy

This is a picture of the feed and return. There is nothing on the tees that tell us if it monoflow or not. How can we tell? The house was built in 1932. Radiators are water heat. We need to add another radiator to the system but not quite sure what to do. These are 1-1/2" x 1-1/2" x 1". (reduced to one inch) .

Thanks in advance for any advice.

EdTheHeaterMan

Nope
Are you sure they go the the same radiator? Or could it be that they are both supplies (or returns) to different radiators? Perhaps first floor and second floor.

Is there a matching pipe next to that pipe running parallel with similar branch Tee fittings (or actually Wye Fittings)?

EBEBRATT-Ed

I would hope they don't go to the same rad as @EdTheHeaterMan said you would get bad flow. Those should be 2 supplies or two returns.

If your adding radiators and you have a supply and return pipes (rad supplies and returns coming off different Y fittings on different pipes) you can use standard tees but I would oversize the branch piping so it would more closely match the flow in the Ys.

You can buy Ys but they are expensive

mattmia2

I think this might be a gravity one pipe hot water system with one run out high and the other low.

Mad Dog_2

Hmm... I'd like to see more & better pictures of the run outs and if he could draw a shop  sketch, Please.  Mad 🐕 Dog

roddyguy

Thanks for the quick responses guys.
My bad. You're correct -- these must be two supplies. Here are more detailed pics of a supply and return, runouts and a radiator.

EdTheHeaterMan

Now that is a gravity one pipe system where the Wye is the supply and the Tee is the return. Not too sure how that will work with a circulator though. Nothing special inside the Wye Fitting. Just the fact that the outlet is on the top of the pipe and the return enters the main pipe at a lower point on the side makes the lighter hot water leave the main to rise to the radiator. The return is connected at a lower point in the main makes that cooler return water find its way back to the main. Carlson's "Law if the Tee" applies here.

Does your boiler hav a Circulator? If yes, what model number?

JohnNY

Good bokeh!

roddyguy

Thanks @EdTheHeaterMan !

The Circulation pump is a

Grundfos
P/N: 59896341 P1
PC: 1437
Class: F

Type: UPS 15 58 PC
60 Hz 1PH
10 uF

EdTheHeaterMan

Operate that on the lowest speed for the best results

mattmia2

They essentially are encouraging the supply to flow in the top of the pipe and the return in the bottom of the pipe.

EBEBRATT-Ed

Agree with @mattmia2 & @EdTheHeaterMan

roddyguy

Thanks all.

Big Ed_4

The Y would be on the return riser .

It is not gravity .

EdTheHeaterMan

Big Ed_4 said:

The Y would be on the return riser .

It is not gravity .

Have you experienced this piping configuration? Please explain how it works.