# Closely spaced tees question



## huffdawg (Feb 1, 2012)

How far apart are a set of closely spaced tee's from each other is there a recommended distance like 12" or so


Huff


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## bigburner (Feb 1, 2012)

Here is the rule, can not be to close. Max center line distance is 4 X dia of the Primary pipe. No closer then 8 x Dia upstream from elbow and 4 x Dia down stream to a elbow. If you violate the rules a little you may get some ghost flow or not completely decouple the loop.[limiting] flow rate] most cases not a huge deal. I have done all of them to some extent, in a complex system with lot of circuits things get pretty spread out.


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## huffdawg (Feb 2, 2012)

I might be breaking a rule on the bottom  is the tee too close to the 90? The tee is downstream.


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## bigburner (Feb 2, 2012)

If the system is dry it's an easy fix, If not try it. I don't think it's a big issue, looks to be 3 diameters. Me I wouldn't change it. It's engineering not a  code.


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## ALASKAPF185 (Feb 3, 2012)

Closely spaced Tee's have to be a maximum of 2 pipe diameters, C-C and a minimum of 10 pipe diameters from any elbow to avoid turbulence and short circuiting, a larger primary pipe helps in tight spaces.  Pretty much make the Tee's touch or use the pre fab units and you'll be safe.  There is alot of info at comfortcalc about near boiler piping , rulz ,efficiency, benefits......   It might mot be a code in some localities ( it is here) but it does effect how the system works. Near boiler piping is the second most important thing to efficiency.


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## huffdawg (Feb 6, 2012)

ALASKAPF185 said:
			
		

> Closely spaced Tee's have to be a maximum of 2 pipe diameters, C-C and a minimum of 10 pipe diameters from any elbow to avoid turbulence and short circuiting, a larger primary pipe helps in tight spaces.  Pretty much make the Tee's touch or use the pre fab units and you'll be safe.  There is alot of info at comfortcalc about near boiler piping , rulz ,efficiency, benefits......   It might mot be a code in some localities ( it is here) but it does effect how the system works. Near boiler piping is the second most important thing to efficiency.



Thanx AL.185  Bpirger et al.       I have it plumbed the same as the photo and it works as good as it should as far as I can tell. But out of piece of mind and now knowning how it is done proper, I'll mostly likley be making it right in the summer.

Cheers all

Huff


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## heaterman (Feb 6, 2012)

The tees should preferably be no more than 4 pipe diameters apart. This can be tough to do with smaller diameter tube unless you use something like Webstone's primary/secondary tee.


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## huffdawg (Feb 6, 2012)

heaterman said:
			
		

> The tees should preferably be no more than 4 pipe diameters apart. This can be tough to do with smaller diameter tube unless you use something like Webstone's primary/secondary tee.



One is 3-1/2 and one is 4  diameters .  Its 1" pipe


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## heaterman (Feb 6, 2012)

huffdawg said:
			
		

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That's OK. The location of that one pair right after the elbow may be problematic in that you may get some unwanted flow in that loop even with the circ not running. Depending on what you have connected there, that may or may not be a big deal.


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## huffdawg (Feb 6, 2012)

heaterman said:
			
		

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Its my DHW  . I did notice that when the circ is not running it does have a small flow when the secondary loop is cool


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## heaterman (Feb 6, 2012)

huffdawg said:
			
		

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Simple fix could possibly be to install a check valve or a circ with a check valve in that loop. I like Wilo's flange set that has the check valve in it rather than going with a circ that has the check built right into the outlet. Less problems.


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