WATER SEAL INSTEAD OF STEAM TRAP

[wsuengineer]

I would like to use a water seal instead of a steam trap. I will design the water seal "p trap" at the highest pressure I expect. This pressure will be 1.75 PSIG or 49 inches w.c. I included a 1 PSIG or 28 inch additional water column above the water seal to aid in back pressure issues. Please see attachment. I am essentialy designing a condensate lifting loop but it is sized to NOT lift the condensate out and prevent steam from escaping. The water seal will be used on a humidification dispersion panel tubes with inlet steam at 1.75 PSIG. My concerns are water hammer, creating a vacuum and filling the dispersion panel tubes with condensate...any others out there. Plus its unconventional.

 

[katmar]

I have not used a water seal as a steam trap before, but my biggest problem in the past with using water seals has been detecting and recovering from blow outs. In your case a blow out of the seal will allow live steam to be discharged. Make sure that it is in a safe area.

The two ways I have used to recover from a blow out are to close a valve at the outlet, or to have a water make up line permanently connected. I share your concern over water hammer if you refill the leg with cold water while in operation. If you use the valve system consider installing a bulls eye sight glass so that you can see when the level is established. It might be a good idea to have the sight glass anyway.

I don't know what your flowrate is, and 1/2" might be big enough, but such piping is flimsy and it might be worth putting in a 1" line just for the mechanical strength.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com