Wet underground return - why install a F&T trap???

elfie

have a vapor system with an underground return that connects to a condensate pump (pipe likely remains full of water and is not fully draining into condensate receiver)



there are no air vents, yet all rads are getting hot



seems installing a f&t trap would not be of <span style="text-decoration:underline;">no value</span> if underground return is filled with water



there are orafices on all the trapless radiators so by the time any steam reaches the end of the underground line it probably has been fully condensed.



end of main is also connected to underground condensate return pipe



thanks

Dave in QCA

possibility

Obviously an orifice system.  In a 2 pipe system, the venting occurs through the condensate return piping.  Is your condensate tank lower than the returns located in the trenches?  If so, that is the route that the venting takes on its way to  the tank, which is open to the atmosphere.



If that is not the case, there must be some other way that venting is occuring.



Curious, do you have key valves on the outlet of your rads?  if so, it is a Moline system.  If not, another type of vapor system.  Do you find any crossover traps?  probably not, since there are also no traps on rads. 



F&T trap is approriate at the low end of a steam main, if it is being dripped into a condensate return line.  However, it sounds like we need more information and some pictures of your system.

elfie

condensate receiver piping

here is a pic showing the underground pipe connection going into the receiving.



you will also see another condensate return pipe joining the flow back to the receiver



there is a slight upward pipe flow (see arrow) which suggests the underground pipe is not fully draining and other returning condensate from above can go both ways (ie. either to underground pipe or to the receiver)



its an Arco model K system that we are trying to figure out (ie. when and why did they install the condensate pump) - the underground pipes have been dug up due to leaks and needed to be replace a couple times over past 10-20 or so yrs.



thanks

gerry gill

they probably installed the condensate pump

because they didn't know what they were doing.