Primary/Secondary piping

J.C.A._3

We've used the 3 ways quite a bit, and they perform as advertised. I haven't had the opportunity to use the 4 way yet...but I'm sure they'll work the same way.

Best advice I can give is to READ the directions all the way through before attempting an install. Many great points and reasons for doing it their way first ! They have had WAY more time to find the reasons why, than you do. Chris

Mark S._2

Primary/Secondary piping

Can anyone confirm for me the distance a primary loop should tie into a secondary loop form a 90 degree turn. I wil try to clarify my question. The building return comes in to the boiler room along the side wall of the room then 90's in front of the boilers at the 90 is the first tee fot the primary loop the 2nd tee is attached directly to the first tee(all fittings are groved fittings snd sre fitting to fitting)

Brad White_9

General Rule O' Thumb

is seven to eight pipe diameters upstream and at least two downstream. This goes for balancing valves, flow meters and a host of other devices. Some devices are more specific and P/S would fall into the same category. I am sure there are other opinions, conditions and exceptions.

Principle regarding fittings is that the turbulence at the turns should not affect the condition in the branch tees. Think of flow rounding an elbow, hugging the outside wall, how that might exit out a tee right after the elbow by it's momentum alone.

The diameters have to do with the wave lengths within the piping, enough straight pipe to settle down and not affect things. Downstream is less critical as you can see -water has gone by, you just do not want too much residual turbulence (back pressure if you will) to affect what is upstream.

The other dominant principle, of course, is that the space between the tees wants to have as little pressure drop/resistance as possible. Don't give the main flow an excuse to jump ship and affect the secondary branch~

My $0.02

Brad

Supply House Rick

Dan's Books

1. Pumping Away
2. Primary/Secondary Piping

These will answer every question you could dream of and more. Click on Shop and you are on your way to Primary/Secondary Heaven. I don't have to say "hope this helps" I know it will...

Rick

Mark S._2

Primary/secondary piping

Thanks Brad for the input the problem the system was having is that the primary loop was not injecting hot water in to the secondary loop. I feel because of the turblance at the 90. I need to find some back up in writing, we removed the 90 and turned the tee around and made the system basicly a reverse return and this seems to have corrected the problem, now the customer does not want to pay because they say this could not have been the problem do to the fact the building is 4 years old so I will have to show them something in writing.

Brad White_9

No Good Deed Goes Unpunished, Mark, Right?

Seems you solved a problem, I had not grasped that. My concern was more of unwanted flow in the secondary. That you have butted P/S tees is a good thing. A little straight pipe upstream and downstream will make it sing. But as you suggest, it is working now, you want to get paid.

Normally I would not consider a primary loop to inject anything into a secondary, rather the secondary would draw (pull) from the primary. More in control that way and not to dwell on semantics.

Was the original building your (your companies) work or responsibility? Or are they blaming you for making a change that created a problem? Curious.

Mark S._2

Thanks Brad, I am just figureing out how to use this I replyed under a thread

Mark S._2

It is a funny situation I worked for the installing company for 18 years a very large company here. when the company sold to a consoildator I did not agree with their ethics and went out on my own.

J.C.A._3

A small comment in a big pond.....

I too searched for the best numbers for "closely spaced tees" and runs up to and between fittings.

I found them by accident while reading the I and O manual for the Taco i-radiant valve. Minimum distance for a straight run before and after the tees, spaced at "so many" pipe diameters apart. I don't remember them off hand...but I now know where to look to refresh my memory when the question arises. (Yet another lesson learned from my old shop teacher, Buzzy...Memorizing formulas is great, but knowing where to look them up, at any given time... wastes so many less brain cells !) Chris

Mark S._2

Thanks Chris I will look on the Taco web-site to see if they list anything there

Ragu_4

Chris

You mentioned the Taco I series; have you guys used them yet? I'm trying out the 4 way valves on two separate jobs (neither job is up and running yet). Heard any feedback anywhere?

Weezbo

today and yesterday..

the i Series R 4 way, Rules! *~/:)i see it as an excellent valve:) and Its Green

something that occured to me is that it would also look good in a light slant fin intrepid Blue:)

justa thought .