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gravity system
 
            
                
                    Steamhead (in transit)                
                
                    Member Posts: 6,688                
            
                        
            
                    I've seen many of these in Baltimore. When dual (combined feeder and safety) valves came out someone got the dim-bulb idea they could handle the pressure by alternately feeding and then releasing water using the dual valve. This saved the cost of a tank. Trouble is, this wears the valves out, and if one of them gets stuck it could cause a leak or even an explosion. 
Whenever I see one of these I sell the owner on a diaphragm expansion tank and a new dual valve and backflow preventer.
                Whenever I see one of these I sell the owner on a diaphragm expansion tank and a new dual valve and backflow preventer.
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            Comments
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            gravity system
 is it possible to have a gravity system without an exspansion tank a closed system0
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            sure .
 pipe goes up the chimney does a u'ie and drops back to the basement floor any expansion runs down the drain.:)0
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 Saw one in the St. Louis area. No circulator, no expansion tank. Was told they relied on the small amount of air trapped in the top of each radiator.0
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            I guess the gypo contractor is not a new phenomenon after all.
 I always thought that all the Dead Guys were good guys. Did you really have to disabuse me of that idea?0
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 Yes and no. Some early gravity systems used an OPEN expansion tank in the attic, so it was an "open" system with an expansion tank.0
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            yes but
 a closed system utilizing the little air pockets in the radiator tops? give me a break. The expansion tank in the attic is legitimate. Air pockets are not.0
This discussion has been closed.
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