main valves and cleaning

plainsman

Have lived in family home for past year. My steam system ( Peerless boiler- gas conversion from oil ) has two main vent valves-one located near boiler and one near end of one steam line ( I have two main lines going out of boiler-each handles 5 radiators) it appears that both of these valves have clogged over time. What should I replace them with? There is  occasional 'banging' in pipes. but Radiators  heat well and I have adjusted and cleaned end valves and pitched radiators

also cleaning question-my boiler water is rusty and obscures part of water level gauge-I check water level each week and drain a small amount each week and refill -do I need to flush system in spring and how do I do it. Thanks....

Dave in QCA

Cleaning Hoffman 75

I have had several Hoffman #75 vents that stopped working correctly.  However, with these, they were stuck open, and never closed. Huge amount of hissing and loosing steam to the atmosphere.   I have been able to make them work like new by using Limeaway liquid cleaner.  I remove the vent, pour a good amount of limeaway int the bottom while holding my fingers on the vent holes.  Then I shake it around a lot, then drain it out, and repeat, perhpas 3 or 4 times.  Then, throroughly rinse with clear water.   When the vent valves were reinstalled, they worked like new.  I would suspect that this would work fine with any brass construction vent. 

You have not indicated what size of vents you have.  It is possible that they are not adequately sized by todays standards and should be replaced.  What size in diameter are your steam mains and how long are they.  That makes a big difference.