Why are some 2 pipe rads supplied from the top, and others from the bottom?

delcrossv · December 18

Last two pipe question for the day…promise!

Is it a supply pressure issue?

bburd · December 18

On a two pipe system, the supply valves can be used to regulate temperature. Most people find them easier to reach if they are mounted near the top of the radiator.

delcrossv · December 18

https://forum.heatinghelp.com/discussion/comment/1827667#Comment_1827667

No other reason? Well, that's a "duh! " moment.

Thanks!

bburd · December 18

I am guessing here, but I've never heard of any other reason.

jumper · December 19

Supply from top pushes air down and out.

But if there's a runout, or even worse, a branch under floor…..

Then steam has to rise in radiator and then switch direction to push air out.

The above may not be exactly correct. Still a way to think about question.

Steamhead · December 19

If the radiator used was a "steam-only" type where the sections were not connected across the top, it would not have had a top inlet tapping, so the inlet had to be at the bottom. The usual radiators used with these systems were the hot-water type, which did.

mattmia2 · December 19

The steam will rise to the top. it will fill diagonally across from the inlet end to the opposite end if the tops of the sections are connected, if the sections are only connected at the bottom it will fill one section at a time starting at the inlet side, once a section is full it will spill out in to the next section.

dopey27177 · December 19

Radiators that have 2 valves at the bottom of the radiator are for piping systems that have vent valves on the radiator. The steam inlet side of the radiator is usually larger than the return. Usually the vent valve is on the return, that's where the vent valve should be.

A two pipe system can have inlet valves that can be adjusted to regulate the steam flow or have orifices the keep the steam flow down to what the radiator needs by the the proper EDR rating,

Typically. if the system is sized correctly from the begging and the T stat is in the right place the radiator valve does not have to be played with!

Jake

PEvans · December 19

My steam radiators seem to be about half fed from the bottom, but not all. Whatever.

I like radiators fed from the bottom. If your steam radiator is fed from the top and the radiator's thermostatic tramp is failed closed, opening up the trap body to service it can yield a pretty big mess.

EdTheHeaterMan · December 19

I find that if the radiator is fed from the top, that it is not fed from the bottom. The inverse is also true, if it is fed from the bottom then it is not fed from the top.

Feeding radiators is an important part of any Radiator Farmers job. A well fed radiator will produce more heat than that of a radiator that suffers from malnutrition. I find that some radiators thrive on a diets of medium to high temperature water while other radiators must be kept on a higher temperature steam diet. Regardless of what you feed your radiators, all radiators waste products are water. That water is always of a lower temperature than the temperature you are feeding it.

A proper and balanced diet with just the right amount of temperature drop will keep your radiators healthy and live a long and productive life.

I hope this information on Radiator feeding is helpful @delcrossv

Yours Truly,

Mr.Ed