Two pipe system no water returning to boiler

bailey23

Hi me and my company just install a PEG225ind utica steam bolier the issuse that we are having is the boiler return is cold and the boiler want to fill after running for 20 min we did remove a hoffman differential loop due it leaking and have read you do not need them considering the boiler only max pressure is 1 psi.

JStar

Any pictures of the job and piping?

Jamie Hall

Oh dear. Well, having taken the Differential Loop out you now have a major problem.

Step 1. Find all your wet returns, everywhere in the system, and make sure that they are all at least a foot below the static boiler water level. Fix as required.

Step 2. Make sure that the vapourstat is set to no more than 12 ounces cutout. If you don't have a vapourstat, get one and install it.

Step 3. All your dry returns must slope towards the boiler, and connect above the water line where the differential loop was (and no lower than the original connection to the loop), and drop from there to a wet return. Be sure that when you ditched the loop that you also removed the steam connection from the header to the loop.

Step 4. All your main venting -- and without the loop you will need a lot of it -- must be where the dry returns join and drop.

Step 4. Go out in the system and find all the crossover traps and make sure that they are operating.

I have to admit that I've never heard of a Differential Loop leaking before. They are a dead simple piece of equipment, and really do wonders for protecting and controlling the system.

bailey23

Here are some pictures

JStar

It's piped incorrectly. Do you still have the manual to look at the (minimum) piping requirements?

Jamie Hall

JStar said:

It's piped incorrectly. Do you still have the manual to look at the (minimum) piping requirements?

A masterful understatement. And if that big cast iron pipe overhead is what I think it is -- the original header -- I''m going to bet that the water level in the new boiler is significantly lower than the one in the old boiler. Refer to Step 1 in my comment above.

Abracadabra

A header feeding a header... that's new. Although strange (and I don't want to be the one to try it) It might work that way... the bigger problem I see is that steam is exiting the header one way and the equalizer is on the opposite side. This equals wet steam. I'd like to see a wider view picture of the old header. Might have to setup a gifford loop to ensure your wet returns stay wet if they are currently on the edge of getting dry. Any water hammer?

Jamie Hall

A header feeding a header can work well -- my system is set up that way -- but BOTH headers have to have an equalizer, and I don't see that. Otherwise that lower header -- the new one -- is going to be full of water with nowhere to go. Not good.

KC_Jones

Jamie, even so the first header is wrong even if the second one wasn't there...unless I am missing something. It's a colliding header is it not? I am trying to figure out why even put the "new" header in? couldn't the take off from the boiler been piped up into the older header directly? The old header still isn't correct with the placement of the equalizer and main connections but they could have corrected that and been in better shape than what is currently there.

Jamie Hall

Oh no -- the new header is quite wrong! I can't even imagine why it's there, and not a swing joint in sight. I was just commenting that -- properly built -- two headers can work.

vaporvac

Jamie & jstar, can the differential loops be fixed? Obviously that piping need reworking, but It would be nice to restore what was there and not worry about the other things if possible.

Jamie Hall

Odds are that the Differential Loop was trashed. They can be fixed, if they were to leak, yes, although if the leak has been going on for a while it might take some ingenuity to repair the threads (which is really the only place I can imagine the leak happening).

They aren't made any more...

The real question, then, is how much of the rest of the piping was changed.

GW

Why not get rid of the old beast at the ceiling and the new header and do a repipe for both? Make a new header with whatever size the manual says and get the equalizer on the correct side on the header, grab the old main (s) with increasing couplings. Also, I thought it's best to drop the equalizer straight into the water with no more than 45 degrees offset as it drops

KC_Jones

I just noticed there is a vent on the equalizer. What in the world could that be for?