couple of steam radiator questions
I recently had a new boiler installed to replace my 1920s vintage converted coal boiler. The system is 1-pipe steam. So this new boiler, in addition to being more efficient, can actually build steam pressure in the system. Steam pressure is nice, but it leads to a couple of problems. The valve stem packing leaks on all the radiator valves. And the air vents don’t seem to be able to resist the steam pressure and hiss a lot.
I had replaced the air vents last year with some I found at Home Depot, but these don’t seem to be up to the task. Anyone have any suggestions on a brand of air vent to use? Are the adjustable ones the way to go (that’s what I have now) or are the fixed ones more reliable?
Also, I imagine this is a pretty standard procedure, but can anyone give me a primer on replacing the valve stem packing? What do I use for new packing?
I was considering replacing the valves, since they are probably original and don’t hold pressure when closed. But the valve I found has a different dimension between the centerline of the radiator nipple and the end of the female threads that the steam supply pipe screws into. So I would have to extend or replace the steam supply pipe (or cut some of the legs off the radiator!)
Are valves for the same pipe size, but with different dimensions available? Is it likely that I would be able to find rebuilding gaskets for the old valves if I disassembled them?
Thanks!
Alec
Replies
20 years ago I was fortunate enough to live in a house with steam heat 2 pipe system. I loved it and loved playing with it also because I was only 2 years out of the Navy where I had been a machinist mate. Thats not a machinist as in the real world but the people who run the engines and related equipment on steam powered ships.
It sounds like you may have your system running at too high a pressure. I think a one pipe system should only operate at 1 or 2 PSIG which should correlate to 214-216 deg F. Low pressure systems can be repacked with teflon rope or string packing. This stuff is probably available at your local plumbing supply or on the internet. The temperature of the rads is controlled by the air valve. the steam inlet valve should be left wide open and the air vent should be cracked open to allow enough steam into the rad to provide the desired temperature in the room. the air vent is also a pressure relief valve and if it is always blowing it means there is too much pressure on the rad. If you close off the inlet completely some steam will leak by and build up in the rad. As it condenses the rad fills up with water and provides no heat.
Dave covered it in a nutshell, but I like to send anyone with a steam question over to
http://www.heatinghelp.com
You'll have your system running better than ever in no time.
...that's not a mistake, it's rustic