How to fix this mono flow rad? (FIXED)

EdTheHeaterMan

sixplex said:

there are 2 1/8 bleeder vents at the top, screwed into what looks to be a reducer, at least 1/4 i guess.

before i do any major surgery on this rad, thinking of connecting the two outlets at the top together.

would not fix the rad but would possibly affect the rads downstream in a positive way

Probably not. using your illustrations I believe that the backwards tee is a restriction for the entire 1-1/4" loop because there is no alternate or return path for the water flow when it gets backed up behind the restrictor of the incorrectly installed tee. It's just restricted at the backwards tee.

This may be more accurate

EBEBRATT-Ed

@EdTheHeaterMan

Mega press couplings won't work. You will never spread the pipes far enough to get them in place. They have a stop, there not like slip couplings.


Make a cut between the two tees remove the pipe and the tee that is backwards and trash them. Put a regular tee in place of the monoflow so you know have 2 regular tees. Use a black tee.

Then 2 threaded adapters, a balancing valve and a union or slip coupling. Done


This one is getting tiring.

Either it is installed right the way it is or it is not. Fix it and move on.

EdTheHeaterMan

@EBEBRATT-Ed, I actually selected the NO STOP coupling for this on purposeTurn the tee 90°. Slide the coupling past the pipe end, then turn the rest of the 90° and align the pipes, then slip the coupling back over the cut. Press away. but from the looks of that location, it is a tight fit for the press tool.

EdTheHeaterMan

EBEBRATT-Ed said:

@EdTheHeaterMan
This one is getting tiring.

Either it is installed right the way it is or it is not. Fix it and move on.

I Agree the first mention of backwards tee was in August when @HomerJSmith gave 4 possibilities: Blockage in the radiator, supply and return inverted, monoflow tee installed backward, monoflow tee plugged

The backwards tee was not verified until Oct 25. If that was diagnosed and verified sooner, the tee could be turned around by now. So much time wasted thinking about how to fix this based on insufficient info.

Simple fix. Put the tee in the right way. I guarantee that it will work when that is done.

Has anybody said it yet? "What goes into a tee must come out of a tee" Gill Carlson

ScottSecor

Megapress is your friend in situations like this.

sixplex

EdTheHeaterMan,

First of all thanks for your input.

1. Both supply and return go 6" up from the main. That's the level they come out from the wall where the rad is. This is to get rid of air. Then both supply and return go down to the rad.


2. Is the return tee even backwards??? On a bell and gossett monoflo tee the arrow points towards the red ring, where the wide part of the cone is. So the supply arrow needs to point TOWARDS the flow, and the return AGAINST. Exactly what your image showed. Is this not correct?




The problem is the SUPPLY tee, it's a regular tee. So the question is what's the easiest way to fix that.

There needs to be a monoflo tee instead of it with the arrow pointing towards the flow

109A_5

Hello @sixplex,
I'm seeing this part built like this, so the radiator works poorly and it diminished the flow through the rest of the loop.

mattmia2

Someone needs to find an armstrong catalog and figure out what the arrow means. Or maybe the guy that's retired that used to sell this stuff will answer, but he absolutely doesn't have to.

109A_5

My guess is BOTH red arrows are the water flow direction and the word "Return" is the position in the system in relation to the Main and the Radiator. The other Monoflo T would be labeled "Supply".
Maybe @sixplex can verify this in other parts of the system that work well (or better).

Are the orifice / venturi the same size with the Supply and Return ?

sixplex

109A_5 you're a genius! never realized it said supply/return

here is an identical radiator, which works! piped the same only inversed, on the opposite side of the building.
it's smaller and uses TWO diverter tees, both arrows point towards the flow, supply tee labelled supply, return tee labelled return

sixplex

109A_5 said:

Hello @sixplex,
I'm seeing this part built like this, so the radiator works poorly and it diminished the flow through the rest of the loop.

if this is indeed the way this rad is piped, they really messed up, no wonder it never worked and the rads after don't heat as well either

EBEBRATT-Ed

@EdTheHeaterMan My apologies. Never new that had no stop couplings.

sixplex

i ordered two of these
https://afsupply.com/pvf/fittings/bell-and-gossett-cast-iron-moniflo-tee-1-1-4-x-1-1-4-x-1-2.html

the outlet is 1/2 on them, not 3/4.


thinking having a machine shop enlarge them to 3/4 (wont be exactly as a proper 3/4 tee but will flow better for sure), and remove the armstrong tee altogether.


does anyone have a better idea? as in easier, nobody in Toronto wants to touch this job so the easier the fix the better, i'm willing to pay whatever it costs

109A_5

Appears color coded too.

sixplex

us canadians need all the help we can get including the colour coding, but every now and then 70 years ago a tee still gets put in the wrong way.

here is a high quality picture of the tees from a different part of the building for anyone dealing with armstrong tees in the future

mattmia2

sixplex said:

does anyone have a better idea? as in easier, nobody in Toronto wants to touch this job so the easier the fix the better, i'm willing to pay whatever it costs

Use copper monflow tees of the proper sizes or use plain tees and a balancing valve to do the same thing as the venturis.

My guess is that the old system was overpumped enough that you got enough flow in this half of the loop for it to heat adequately (but probably not this radiator) even though the flow in this loop was a lot less than the other half of the loop.

109A_5

Hello @sixplex,

If that is all you can find as a replacement Monoflo T. I would NOT modify it, it may weaken the casting. Unless you are reasonably sure it is the same casting as with the 3/4" version. I would go with the 1/2" pipe (close nipple) for as short a distance as possible then back to 3/4". That radiator and that whole loop may work a lot better after the repair.

sixplex

109A_5 said:

Hello @sixplex,

If that is all you can find as a replacement Monoflo T. I would NOT modify it, it may weaken the casting. Unless you are reasonably sure it is the same casting as with the 3/4" version. I would go with the 1/2" pipe (close nipple) for as short a distance as possible then back to 3/4". That radiator and that whole loop may work a lot better after the repair.

Fair enough. So use an adapter to go from 1/2 to 3/4, correct?

How about reusing the existing Armstrong 3/4 on the return in the correct orientation
and using a Bell and Gosset 1/2 on the supply with a 3/4 adapter?

EdTheHeaterMan

It seams that all the repairs suggested involve draining the system to do some piping near or around the Monoflo® tee. I believe that is the case here. Anyone that is suggestion anything more than installing that tee in the proper configuration is just asking you to spend more money than you need to. I am guilty of that when I assumed that the tee was correctly installed, I said a circulator pump would fix the problem. Even though it would fix that radiator problem, it was more money than needed to make the proper fix.

Knowing that the Tee is incorrectly installed, The only recommended solution should be to install the tee correctly. @sixplex, You would be amazed at how well this stuff works when you follow the instructions. Too bad the original installer of that tee is not around anymore. He may have covered it under his lifetime warranty. But that warranty expired when he expired.

sixplex

Bell and gosset specifies 2 tees for any rad below the main.

Would 1 monoflo tee on the return side in the correct orientation even work?

Would 2 bell and gosset 1/2 monoflo tees work better?

Or one 1/2 bell and gosset on the supply and one 3/4 armstrong on the return?



This radiator never had a balancing valve originally, there is one now. If there is too much flow i can restrict it. What i can't risk is paying for the work, for example only changing the orientation of the return tee, and then having to pay again to fix it if the rad still doesnt heat up.

109A_5

Hello @sixplex,
I'm thinking the Monoflo T as a set was an engineered strategy to maintain the same cross section area as the Main pipe while diverting a portion of the water through a radiator. So the first Supply T is a diverter and the Return recombines the flow and maybe with the added a benefit of the Venturi effect to enhance the flow through the Radiator branch. Resulting in good overall loop flow and good radiator flow.
Reusing the existing one by flipping it around may work, but it may break the advantage (if any) of a proper set, since the Venturi maybe a different size and/or length. I wonder why Armstrong had one of each (Supply and Return) and others don't ?
Since your Radiator is below the Main I would definitely use two as a set and installed in the correct flow direction.
In this case not a big fan of the balancing valve (in-between Monoflo T's) since it is a restriction not in the original engineering. It may also seriously reduce the Venturi effect. As far as valves, how are the other radiators set up ? Do this one the same.

sixplex

Thanks 109A_5 !

I agree, set of 2 Bell and Gosset, seems like the way to go.
The 1/2 instead of 3/4 isn't ideal, but the radiator should work, and likely the rest of the system would work better.

As far as balancing valves, 95% of the rads are cast iron baseboard and they all have
a balancing valve on them meant to regulate the flow to some extent.

Emailed Armstrong with a request for literature. Not hopeful, but you never know.
My guess it is the same monoflo Tee as all the other brands, they just labelled them so that people are less likely to screw it up.

mattmia2

My guess is that the product got sold to B&G at some point since they are both branded Monoflow.

109A_5

Hello @sixplex,
Yours was the super minimum flow setup (not listed).
Other info.
https://s3.amazonaws.com/s3.supplyhouse.com/manuals/1350220861259/82323_PROD_FILE.pdf

hot_rod

Know also that there is a lot of pressure drop involved with diverter tees. Every 1-1/4 tee is worth 25' of pipe. The Cv value assumes no flow through the side port, according to the B&G equivalent length table.

And radiators are in series, so the last radiators will see a lower, maybe much lower temperature.

sixplex

venturi doesnt seem to specify using 2 tees for downfed rads.


concerned if i put in two tees, that rad might take too much heat out the water affecting the downstream
ones.

safest choice is to maybe reverse the existing tee? rads should get some flow, and the downstream ones will work

not sure how to decide on this

109A_5

Hello @sixplex,
That whole loop was limited or restricted by the backwards Monoflo T (Red Arrows). Your new 1/2" ones may have a bigger orifice since the branch is smaller. The old Monoflo T may have to be cut out and may become useless.

If you want full control (with no major restrictions is possible) just add two valves while it is all apart. And install both Monoflo T's correctly. This covers all the bases in one shot.

sixplex

thanks 109A_5, you're the best!

waiting for the Ts to arrive, will report back when it's all done.

EBEBRATT-Ed

@simplex

Why don't you take the simple solution and install 2 regular tees with a balance valve?

That way you can adjust the flow needed for the radiator and get the heat you need without overly starving the downstream radiators.

Furthermore, the discussion about running the downstream radiators at a cooler temperature is (or should be) moot. When the system was designed, the installer is supposed to adjust the radiation size based on the water temperature.

Same way it is done in a series loop system where the water temperature at the end is always cooler than at the supply.

mattmia2

please edit to remove pricing. safest bet is 2 plain tees and a balancing valve in the main that will let you divert however much you need to the emitter

sixplex

Can't edit that post anymore, sorry.  
The point was it's a hard job nobody wants to do,   not the money. 

The main is inside a ceiling, sealing a valve in there isn't great. This is in a small apartment building covering up the hole with an access panel will increase sound transfer between apartments.

EdTheHeaterMan

sixplex said:

Can't edit that post anymore, sorry.  
The point was it's a hard job nobody wants to do,   not the money. 

The main is inside a ceiling, sealing a valve in there isn't great. This is in a small apartment building covering up the hole with an access panel will increase sound transfer between apartments.

There are 3 dots on the right side of your comment, click on the 3 dots and a one item menu will appear. click on edit and you will have access to the comment to edit it. When finished editing, go to the bottom and "Save Changes"

sixplex

so the plot thickens, supplier shipped wrong tees, not the ones pictured on their site, they don't have others.
they are scoop style labelled as "supply tee".

from what i understand a venturi (orifice) should be used on the return.



also found documentation on the Armstrong monoflow tees (what i have in the system.

looks like they're orifice type.

something very interesting, apparently the 1-1/4 armstrong diverter tee has the equivalent of only 7ft of pipe, i keep seeing 25ft for other brands of tees, weird.







can i use, a 1-1/4 x 1/2 (connected to 3/4 pipe) scoop style tee on the supply,
and original 1-1/4 x 3/4 orifice on the return?

can anyone help sourcing TWO, 1-1/4 x 3/4 orifice style monoflow tees? that would be ideal for me

EBEBRATT-Ed

I see no reason that you could not use those tees on the supply or return if the orientation is right. All the manufacturers of diverter tees, Monoflo tees etc whatever you call them allow you to use two tees if the branch pipes have high resistance.

I have never seen a manufacturer make "supply" and "return" tees it all depends on how they are installed. Maybe someone will prove me wrong.

I still say two regular tees with a ball valve in between would avoid all the confusion and give you an 'adjustable Monoflo.

Monoflo systems were commonly installed in the 50s and maybe the 60s and not much after that. So, tees are not as readily available as they used to be.

EdTheHeaterMan

EBEBRATT-Ed said:

I see no reason that you could not use those tees on the supply or return if the orientation is right. All the manufacturers of diverter tees, Monoflo tees etc whatever you call them allow you to use two tees if the branch pipes have high resistance.

I have never seen a manufacturer make "supply" and "return" tees it all depends on how they are installed. Maybe someone will prove me wrong.

I still say two regular tees with a ball valve in between would avoid all the confusion and give you an 'adjustable Monoflo.

Monoflo systems were commonly installed in the 50s and maybe the 60s and not much after that. So, tees are not as readily available as they used to be.

This:
But I'll bet you Dollars to Doughnuts that they are identical inside and just painted a different color and labeled with different arrows.

And you are correct. Your regular tee with a valve plan will work fine. But I wonder why everyone is reinventing the wheel. All @sixplex needs to do is to install the tee he already has, the correct way. It is working on the neighbors home with the identical system because they didn't make the mistake.

To Quote a very knowledgeable colleague "Maybe someone will prove me wrong"

sixplex

My tees, by Armstrong, are just painted differently, correct, according to the newly discovered specs I posted, because they are cone type not scoop type.

Legend Valve still makes copper diverter tees, both scoop and cone type. In their instructions they they don't suggest the scoop is used for anything other than supply with a regular return.

Cool graphic 

EBEBRATT-Ed

@EdTheHeaterMan

I had a 1950s Monoflo system in my house which I lived in for 34 years until I sold it 3 years ago. I don't remember who made the tees it was a name I never heard of before. On one side of the tee it said "return" with an arrow pointing to the right on the other side it said supply with an arrow pointing to the left.

sixplex

Wanted to thank you all guys for your help, each and every one added insight necessary for me to understand the problem.

Rad has been repiped using two b ang g monoflo tees, and is now possibly too hot

EBEBRATT-Ed

lets see the tees

sixplex

before


after



Needed 1-1/4 by 3/4. Could only find 1-1/2 by 1/2. Had a machine shop enlarge the 1/2 to 3/4, used reducing bushing on the 1-1/2. Spray painted a "ring" on them.