Posted by Brian on January 24, 2000 at 21:22:04:
In Reply to: Re: Tuning Steam System posted by jtown on January 22, 2000 at 12:41:11:
They do make thermostaticly controlled bleeder valves for one pipe steam heat. You should never control steam comining in to the radiator by the shut off valve for this restricts condensation leaving the radiator as well. I had the same problem in my home. The shortest run only feeds two radiators. and is a total length of 8 feet. where the longest run in the house feeds 4 radiators which is over 30 feet long. If you take either a 1a bleeder valve which is adjustable or an (expensive) thermostat valve instead of restricting both steam and water return you are adjusting how quickly the steam bleeds out the air in the system. Which in fact slows down the 8 ft run and speeds up the 30 ft run.
thermostatic bleeder valves are avaialble in a heating supply house and must be ordered usually. Hoffman makes one that sells for around $50.00 per valve. What these valves do is once the heat in a room reaches the valves set temperature it shuts the bleeder valve and does not alow any aditional steam into that radiator. You may see in large radiators that they will only be half way hot but the temperature is where it should be in the room. This meathod of trying to ballance the system can be very affective if you have one of these valves on each of the radiators if you get a really good hydrostat on the boiler and your system is totally sealed. How you can use this meathod you set your control valves to the temp you want in each room and remove the thermostat in the house. the hydrostat will alow the heater to run till the shut off pressure. as a radiator is needed to alow more steam into the system it bleeds off the pressure in the system till it hits the low pressure cut in mark this will keep the boiler on intill all radiators that are asking for more steam are satified and the pressure of steam builds back up to the shut off pressure. This will not work unless your one pipe steam heat has a seperate return line for condisation the pressure will hold your condsation from frowing back to the boiler
Brian