I received a phone call from the owner of an oil company in the Boston area whose customer had a steam boiler that failed and needed to be replaced.His salesman went out to review the system and come up with a quote.He came back to the office with a question.The system was a two-pipe steam system,but there were no traps on the outlet of any radiator.The salesperson had never seen a system like that and was looking for advice before he quoted the customer on a new boiler.The owner called me to find out what kind of trouble they could be getting themselves into if they proceeded.I talked with him about how two-pipe steam systems with dry returns have to operate.A two-pipe steam system with dry returns has to have traps on the outlet side of every radiator.It has to!Why?First,we need a good understanding of what a dry return is.When they say dry,it doesn't mean it is always dry.It will,in fact,get wet any time condensate is flowing from the radiator and back to the boiler room.
展开▼
