Drip hooked to dry return incorrectly

AlexT

HI,



I have a one-pipe parallel-flow steam system with a dry return.  There is a fairly new Ventrite #7-5 main vent hooked up to the system in the appropriate place, about a little bit before the dry return hooking into the wet return.



The main vent seems to working, but it doesn't actually release air for all that long.  The system starts up, the main vent gets hot in a few minutes and then it's done.  Meanwhile the radiators upstairs are always very loudly letting air out every cycle. 



I believe the drip from one of the risers is incorrectly linked to the dry return.  If you see the photos, you can see that the first riser off the main has a drip that connects right to the end of the dry return.  My belief is that this is incorrect.  This basically would take the steam right out of the boiler and directly to the main vent, shutting it off.



To fix it, seems I can do any of the following:

1) take the drip and run it directly down to the wet return which is directly below the drip. 

2) leave the connection in place but add a 5' wet loop to create a water seal per LAOSH.

3) add some kind of steam separator to the existing pipe.



My gut feeling is that the first option is correct.  What would you do?



-Alex

Rod

Returns

Hi Alex- Dropping to the Wet Return is the simplest so makes the most sense. You might also want to change your return piping so that it reduces on the vertical The way it is now ( see attached picture) the water pools behind it in the return line . I don't know if this is causing you problems but it could.  I would change the main vent to something larger like a Gorton #2. Ventrite main vents are a bit on the small size capacity wise.

- Rod

AlexT

Vertical?

Rod,



I'm trying to figure out how vertical runs could be a problem. Do you mean there is excess horizontal room to cause water hammer?



So far the near boiler stuff seems quiet and working OK. But I can see if I change the dry return to work as designed it might result in some new issues in that pipe area.



Only problem with going to the wet return will be that I will have to empty the entire system and refill it. I think it should be OK, but sounds like better to be spring or summer project.



-Alex

Rod

Reducer

Hi Alex - Sorry I guess I didn't make myself clear. I was referring to the reducer fitting on the end of your return pipe (See arrow in previously posted picture)   Reducing on the horizontal ( unless you use an eccentric reducer) causes condensate (water) to pool behind the reducer. (See attached drawing) Generally you should try to avoid this situation. I just thought I'd point it out to you as in some circumstances it can cause problems. If it isn't doing so now I'd just leave it alone.

- Rod