I have to replace a radiator valve. I have a hot water system, but all I can find are steam valaves in the size I need. Looking at the valve, it looks pretty much the same. It seems like it would work, but it is a Steam valve. Will it work in my hot water system? Why cant I find a Hot water radiator valve over 1?
A steam valve on a residential radiator is usually a cylinder valve, the steam rises up through the cylinder inside the valve and out through a port cut in the side of the cylinder when the port on the cylinder and the valve outlet are in line the steam flows, by turning the valve handle it rotates the cylinder to misalign the port and outlet stopping the flow. A radiator valve for a water system while identical to look at has a stem and a rubber washer which makes the seal, steam would quickly erode this rubber, however a steam valve installed in a hot water situation will work well as a balancing device, I couldn't guarantee it could be used to completely stop the flow, but for average use absolutely, you can interchange the valves, and by the way, residential steam pressure is much less than a hot water system but the steam valves are adequately rated.
Hot water would be a gate type valve or a valve that turns to be opened, and the steamed valved would be a pressure valve where the steam pressure would build and then push out through tensioned valve.
Seems to me that a steam valve would need to hold a lot more pressure than a hot water valve. Steam is a high pressure gas and water is a liquid irregardless how hot it is (below boiling point) I am not a qualified plumber or boiler tech but personally I wouldn't use a steam valve for water or vise versa.
