Posted by captain on October 18, 2001 at 19:04:49:
In Reply to: 2 pipe steam radiators posted by M.Cordrey on October 14, 2001 at 05:07:15:
ok maybe i can give you some useful info. first air is lighter than steam. if the radiators are full of air no steam can get into the radiator. your trap is supposed to relieve the air but this depends on what type of two pipe you have and if you have a trap at all. this will be located at the bottom. does your return pipe go back to a dedicated return or just connect back into the same pipe as the upper line. try bleeding off the air at the hand valve at the top if you start to heat then its air but this could be due to a plugged trap or return line. ok now if you do have a trap on the return and this return line connects with others and goes back to the boiler you will have to have a tank and pump to push it back to the boiler. now if you do have some type arrangement as this then check to see if someone installed a second large trap in this line between the returns off your radiators and the tank . if you do then some bright individual has gang trapped your system because more than likely they had alot of steam blowing and didn't want to replace alot of traps so he put in one trap to hold that steam back ( see dan holman's website or books for info on why not to do this) a radiator that is correctly piped and fitted with the correct valves and trap if needed should only need service once every few years and replacing the radiators serves no purpose because it has no brains "you give it steam and it gives you heat" any of these valves that is leaking needs to be replaced but you may want to check your options in that they have auto valves as well as manual hope this helps if you have any more questions hit me back CAPTAIN