Taco circulator flanges - BAH

[pybyr]

Hello all--

tonight was the momentous occasion to fill and pressurize and then hopefully fire my system, at least in its "Mark I" (heat the house before I freeze or have to buy oil) mode (the wood cookstove only goes so far when the outsize temps are in double digits below zero)

back when I was acquiring components, I ran across a heck of a discount deal on some Taco 1.25 threaded flanges. got some thread-to-copper adapters to match.

being that I have been accused of going overboard on tightening things in the past, I gooed these up with good teflon bearing pipe dope and tightened them until the threaded fittings seemed to find a happily tight place- but I did not crank them within inches of their lives

well, tonight, as I fill the system, the darn things are weeping here, there, and everywhere, at the threaded joints.

NONE of my other joints are.

I am not running high psi- only about 12 psi to start

I conclude crummy Q/C on the threads.

Now I am disassembling and re-tightening (and swearing)

Wanted to pass this along in hopes that someone else can skip such misery

 

[TMonter]

Wrap pipe threads with three wraps of teflon tape and then add the teflon pipe dope. Done a lot of low pressure boiler systems (30psig hot water) and that is what we typically do.

 

[pybyr]

Thanks- someone had warned me against use of teflon tape in a hydronic system, on grounds that bits of tape supposedly can get in the system and foul things up.

___all___ my other fittings are fine. I've done a considerable amount of plumbing over the years, usually on domestic water systems with much higher PSI, and have never run into a situation this bad.

these things are the only culprit, and they are leaking even after considerable additional tightening

I detest them

 

[jebatty]

Some claim that pipe threads on the pipe, not the flanges, are the source of the problem getting a leak-free fit. I've always expected some problem when I mate copper to steel, need to get these tight. At the same time, I only use teflon tape, about 7-9 full wraps on 3/4" and larger, and 5-7 on 1/2". The problems have just about gone away since I increased the number of wraps to these ranges.

 

[stee6043]

I used the Loctite teflon "rope" on my system at all connections. I'd run a little dope (Rectorseal), 7 or 8 turns of the rope and then more dope. Not a single leak. You can buy the Loctite stuff at grainger.com.

 

[Northwoodsman]

I've done a fair amount of my own plumbing (installed propane boiler and most recently installed my EKO40 with storage).

Having learned from joints that leak, I have determined that the number of wraps and not over torquing are the 2 most important features of a leak-free threaded joint.

I use 6-7 wraps of teflon tape and just make the joint snug with a a decent sized pipe wrench.

Hope this helps !

BC

 

[steam man]

I've seen it all when it comes to threaded fittings leaking. I like the dope-tape-dope trick but the real problem is the copper male threads. I would bet they are Chinese made and just don't work, especially larger sizes. I've wasted way too much time on bad fittings. Any project I do will have American made fittings or at least have an american brand on them.

Mike

 

[chuck172]

I use wicking and a black permatex type sealant like grip etc.
If you really want a leak proof sealant, try expando, if you can find it. You mix it with water, makes a paste that hardens like cement.

 

[Plumbit]

I agree it is the copper X male adapt. I scar the male threads with pliers to make grooves then I wrap wicking (thin cotton string) around the threads and add Mega-Loc a liquid teflon dope. The cotton wicking is jammed in the threads by the scars and when water seeps into the threads it swells and stops the weeping. I always seem to have problems with teflon tape and go back to the wicking. when desperate I pulled thread from my socks,rags,cotton towels, the thread must be cotton. Allot of old wood boats used a cotton caulking that was then covered with a lead based caulk with great success. (the EPA shudders at the thought of lead today)

 

[in hot water]

Why not sweat flanges? If you are trying to connect copper to the circ flange there are a bunch of sweat flanges, including Taco, on the market.

Or an iso valve/ sweat flange like B&G;Webstone, Grundfos, etc. Iso valves should be required on all circs. That coming from a service persons opinion

hr

 

[mtnmizer]

Would doing an air leak test prior to filling be
of any value? Fill it to 80 lbs and soapy water
on the joints..

 

[Rickard]

I have also had the most success when using teflon and pipe dope together. Dope on the male side, 6 wraps of teflon and no leaks even with cheap Chinese fittings.

Dean

 

[Tarmsolo60]

Would doing an air leak test prior to filling be
of any value? Fill it to 80 lbs and soapy water
on the joints..

I would only try this if you could isolate and not pressurize the boiler cavity. large volumes of compressed air are dangerous. boiler manufacturers pressure test with water.

 

[pybyr]

Thanks for the input, everyone. If it is the copper X male adapters, what's puzzling is that the same type and make are not leaking where they meet iron.

So here's my next question- last night, I had the whole thing ready to go for a first burn, and it was 25 below out; with the oil tank rather low and the wood cookstove "not cutting it" After re-tightening these fittings each as much as I could, I finished filling the system, including using the quart of Gunk/ Solder Seal "Liquid Boiler Seal" that Econoburn sent with my boiler.

And then I fired it up.

The small leaks ceased quickly, and the one drip that kept going slowed as time went by- and by this morning, it too had ceased.

And I have heat, like never before, even with a low of around 30 below last night. It's wonderful.

my question is this- to what degree can I hopefully count on the "boiler seal" keeping those little weeps in the fittings closed up, or should I plan, during some moderate weather spell, to pull these apart and re-do?

Thanks again for all the help

 

[Tarmsolo60]

If they stopped I would leave them alone. the only reason to drain it down for me would be to solder in some new webstone flanges. Put a set on your shelf and when you need to drain it down sometime put them in.

 

[pybyr]

Why not sweat flanges? If you are trying to connect copper to the circ flange there are a bunch of sweat flanges, including Taco, on the market.

Or an iso valve/ sweat flange like B&G;Webstone, Grundfos, etc. Iso valves should be required on all circs. That coming from a service persons opinion

hr

I'd gone with these threaded flanges (which do have isolator valves- I have used valved flanges throughout) because I ran across an exceptional deal on them- about 1/2 the cost of regular sweat flanges in this size, and I figured that with the thread to copper adaptors, I'd be all set. I even soldered the copper pipr into the thread adaptors before installing in the fittings, and then used a sizeable wrench + vise to tighten the threaded fittings into the flanges. ....

 

[Tarmsolo60]

If they are isolators, than I wouldnt replace them, I was thinking they were the basic threaded cast iron flanges.

 

[Tarmsolo60]

Also forgot to mention, Congrats on getting your system online.

 

[DaveBP]

When I have put threaded iron pipe together I have taken a pipe tap and die and just chased the threads to clean up the dings and galled surfaces, not even a full cut to new thread surface, just clean up what's there. Fittings come together another full thread or more just from that. It's gotta help.

But I work in a machine shop and can borrow the tools. They are very expensive in the bigger sizes of hydronic systems.

 

[mtfallsmikey]

Did you thread the male adapters into the flanges, then solder copper pipe into them?....a BIG no-no.

 

[pybyr]

Did you thread the male adapters into the flanges, then solder copper pipe into them?....a BIG no-no.

no- see above, I carefully sweated the adapters to the pipe, let them cool, then applied abundant teflon bearing pipe dope, and cranked them together using a plumber's vise and a pipe wrench until I started lifting the bench with the force of the wrench.

I'd have thought that that'd have been enough to get a good seal.

ndeed, such a techniques was good enough to get a perfect seal wherever else copper met threads in other parts of my install- just not on these blankety-blank discount Taco bronze valved flanges. that alone tells me that the flanges' female threads had lousy Q/C

The happy ending is that the dripping finally stopped after running the system for a few hours with the boiler seal goo (supplied with my boiler) circulating in it all

 

[Willman]

Hey Trevor, how about some pics of your install ? I am interested in your piping loop in relation to your boiler. Is your storage online also ?
Will

 

[Der Fuirmeister]

Why not sweat flanges? If you are trying to connect copper to thecirc flange there are a bunch of sweat flanges, including Taco, on the market.

Or an iso valve/ sweat flange like B&G;Webstone, Grundfos, etc. Iso valves should be required on all circs. That coming from a service persons opinion

hr

I'd gone with these threaded flanges (which do have isolator valves- I have used valved flanges throughout) because I ran across an exceptional deal on them- about 1/2 the cost of regular sweat flanges in this size, and I figured that with the thread to copper adaptors, I'd be all set. I even soldered the copperpipr into the thread adaptors before installing in the fittings, and then used a sizeable wrench + vise to tighten the threaded fittings into the flanges. ....

I'm betting I got some of the same flanges for our shop heat system. Has anyone ever used fuel rated Teflon pipe dope? We use it to plumb the diesel fuel systems on generators at work. The stuff is so thick that I don't believe we've ever had a leak. Circ. pumps, valves etc. Fuel systems are all pressure tested.

 

[mtfallsmikey]

I would fault the threads on the copper male adapters more than the flanges...they drove me nuts for years in the heating trade...I've been a big fan of Rectorseal and Megaloc pipe dopes for years.