Old radiators valves

GeorgeV

I have a 1929 two pipe system that has been converted to a gas boiler. I have recently done some work on the radiators in an attempt to get them heating fully. I have replaced all of the traps on one return loop of the system (5 radiators). The radiators seem to be heating better but there is one radiator that has a new supply valve on it which heats much quicker and all the way across. The radiators without the new supply valve do not heat all the way before the thermostat is satisfied.



This led me to question the original 1929 valves. They are simplex speciality valves. I took an extra one apart to look at it and there is a small orific on the intake side which is closed by a pin that is lowered when the knob is turned. The opening and the pin that closes the supply look striking similar to the opening on a stem trap.



Therefore, it seems that the old valves have a very restricted opening to let the steam through and the new valves would be letting much more volume through. Can anyone explain why these old valves are designed this way and what effect it is having on my system? The old directions for the original furnace and the original pressure gauge indicate that the system was designed to regulate temperature by adjusting the pressure in the system (1-30 pounds depending on the outside temperature). Should these valves been changed when the system was converted from coal or are they doing what they are suppose to be doing? Thanks again for your help.

Steamhead

They are "orificing" valves

which could be set to limit the amount of steam that could get thru, to what the radiator could condense. This helped balance the system.



With a newer valve you can add an orifice disk to the union where the valve connects to the radiator.

GeorgeV

That explains a lot.

That is why my system has been running relatively well with 80 year old traps. So I shouldn't be concerned if a radiator is not heating up completely so long as we have enough heat for the particularly room? I was worried that the system was not running efficiently since the radiators were only heating half way and the traps are so old. So I guess I should leave them in place and not worry about the traps staying cold in a normal heating cycle.

Jamie Hall

Exactly

in fact, some orifice systems don't even have traps -- or need them.  But one does have to be a bit careful of pressure.



On that one radiator with the new valve which is heating all the way across -- you may want to partly close its valve, which is quite acceptable on this type of system, so that it heats more like the others.  Unless you like the extra heat, of course!

GeorgeV

Thanks

Thanks for your quick responses. It is nice to know I can get these questions answered. Even though I am in a relatively large city, it hard (impossible) find anyone who has the knowledge locally, and I have tried.

Steamhead

What large city

are you in? 

GeorgeV

5 hours south of you

in Roanoke, VIrginia