new piping config

bauer

Hi there...



I've been trying to research upgrades to the piping of a boiler for the 2nd/3rd floor of a duplex I have. I am working off of 'pumping away' for a few reasons -- 1 because we have had a lot of air problems, and 2 because I just like things done right.



In an effort to create something that functions and looks good, I'd appreciate some feedback on my dry fit here. The first picture shows the current set-up, with the pump on the return side. On my mock-up, I have piped up to a drain valve, then straight into the B&G air separator and out to the circulator pump. Out the top of the IAS, I will pipe a 3/4" line pitched up to an airtol fitting into my existing steel tank. The fill valve will connect in the bottom opening in the IAS. All of this is out of page 53 of pumping away.



I do have a few questions....



1 - these components are a lot heavier than I expect -- do you just let the pipe absorb that weight or is it best to provide some support?



2 - the information with the airtrol fitting suggests piping the fill valve into the line that goes to the compression tank. It also says not to install a valve between the boiler and the tank. Both of these things seem to be contradicted by Dan's book --- his diagram shows the fill valve connecting at the bottom of the separator, and also installs a ball valve between the tank and separator.



3 - Do I need to install check or flo preventer behind the pressure reducing fill valve? There was not one on there before...



any other general observations are greatly appreciated.... Thanks!

Tim P._3

My .02

1. When in doubt.. support.  It's probably not that bad when you get supported piping connected to the other side of the circulator.  However, if you feel it needs support, go ahead and do it.  What size iron pipe is that 3/4?



2. The valve between the expansion tank and the system is so you can service the tank easily.  No issue there.  If you left the valve closed by accident the system would just discharge through the T&P when the water expanded.



3.  Yes, you should install a backflow preventer such as a Watts 9D.  If you have chemical additives in the boiler you should be installing an RPZ-type.



General observations.. I would have ran the piping full size to the circulator in case you add a second zone or an indirect.  What is your heat loss ofr the house?  You should have 12" (with 1" pipe) of straight pipe before you enter the circulator.



Don't have the book, but are you sure that matches the diagram?  I don't see why there would be a boiler drain before the shutoff valve.

bauer

thanks

when you say full size what is that typically? The initial set up had 1" copper pipe on the return and supply side. Not planning on adding anything... but are you saying a large supply to the circulator just allow for more gpm's if I added more zones? gotcha.



Didn't figure a heat loss for the house because I didn't swap boilers or piping or circulators...was just trying to move things around a bit. so the iron pipe is 3/4"... you're saying I just swap it for 1"?



as far as the diagram... it places a drain there in order to purge the system

bauer

got it...

ok I checked out the original piping...seems they reduced 1 1/4" down to 3/4" on the supply and return.... which is why when I bought my black iron I just went with 3/4".



based on your advice and looking back again, I'm going to replace it all with 1 1/4" as that was the full size from the boiler.



Will also increase the distance of the circulator from the elbow





thanks!

ColoradoDave

Black Iron....

I'd recommend using copper instead of black iron.... it's a little more expensive, but I've seen enough black iron rot out that I don't use it except for gas.

Not only that, but you have more flexibility with your layout custom cutting your pipe (I'm assuming you're buying your black iron cut & threaded, vs threading it all yourself).

Also, if you've had air problems in the past, moving the boiler pump to the service side of the boiler so it's pumping up will help keep air moving in the system so it gets back to your air seperator... just my humble opinion.

ColoradoDave

Pumping Away?

Tim's right, keep it 1 1/4" if you can.  Is it safe to assume that if you're reading Pumping Away you've also read Primary / Seconary Pumping?

If so....  leave Primary loop at 1 1/4".  Secondary loop can be smaller depending on number of zones.

If NOT and you've got a 1 pump system, then I'd recommend staying 1 1/4 through the pump and then breaking down after the pump for your zones.  Also, consider tying the service and return manifolds together with a 3/4 pipe with a ball valve on it throttled back halfway.  So you get some flow that goes directly back to the boiler and the rest goes to your zones.  This keeps your boiler getting lots of flow so it stays hot and reduces condensation in the boiler while the zone still gets plenty of flow.  AGAIN... only use the bypass if you're doing a single pump system.