Injection piping question

Mpj

Went to a job today to help an electrician friend wire a injection system installed by somebody else. The supply injection leg was taken off the supply header (Weil Mclain CG series boiler) and the return leg was taken off the return header. The injection pump was on the return side of the loop pulling away from the radiant manifolds instead of "injecting" into the manifold tees.

I have never seen this done before, do you think that the system will work properly?

Thanks,

MPJ

Ironman

Injection Pump

There should be an injection bridge piped between the manifold loop and the primary loop with two closely spaced Tee's.



I'm not sure I'm following your description. Can you post a pic or a diagram?



See the attachment on injection piping.

Mpj

Injection loop

Having trouble uploading a picture. Something about a "tif" to a "pdf".

Brad White

If

your boiler supply and return are on opposite sides of your boiler (with intermediate piping or anything other than closely spaced tees or other hydraulic separators), you can count on that circuit forcing water into your secondary circuit.



Ironman is on it. You need a bridge spanning the primary/secondary sides, running between pairs of tees on each circuit.



Can you post a diagram or photos?

Terry O

File conversion

Tiff to pdf file conversions can be done through any one of many file handling programs. Irfanview for instance - http://www.irfanview.com/ - ....Or if you'd rather not want to download and install one of these, you can use an online conversion program.... see link: http://docupub.com/pdfconvert/

Good luck!

Mpj

injection loop

Sorry for the crude drawing but art is not my specialty. The injection legs are coming off the supply and return headers same as the other zones. the injection circulator is pulling from the tees. I have never seen it piped this way before and I was just wondering if you guys would think it work or not.

Thanks,

Mpj

Mpj

injection loop

Terry O, thanks for the info. It took a little while but I got it.

Ironman

Missing Circ?

You're short one circ. - The injection circ!  It should be in the bridge between the main loop and the radiant loop.



No, it won't work. What is there to cause flow in the bridge between the loops? The variable speed injection circ. must be in the bridge. And you'll still need a circ. in each loop - the primary and the radiant.

Mpj

injection loop

I made a mistake on the drawing. The only closely spaced tees are at the radiant loop. The injection legs are connected directly to the boiler headers.