Circulator Substitute plumbing

[Nofossil]

Once again I need to tap the collective wisdom of the forum.

I'm moving a circulator to a different spot and I need a straight section of pipe where the circulator used to be. It's near the boiler and access is awkward at best. What I'd really like is a section of straight pipe with circulator flanges that I could just bolt in where the circulator used to be. The circulator itself has grooves in the flanges for the square seal ring - the mating flanges are flat.

Does anyone have an elegant solution for this? The best I've come up with is to use a section of threaded black iron with flat flanges and make EPDM gaskets. I'd hate to go down that path and find out that it's a bad idea.

 

[maple1]

Are all flanges flat? I might be misremembering but I thought some I brought home when I was doing my system also had grooves. I should go rummage my basement & look, might be some leftovers down there.

But if not - your idea sounds like it should work? If you can't get an off the shelf BI nipple exactly the right size (not sure how rigid the spot is), you could go with copper with threaded adaptors on each end, bolt it all in place, and then sweat the adaptors last. Well, that might not work due to too much heat on the gaskets, so maybe solder in place without gaskets then remove, add gaskets, then bolt back in - but you should be able to get to the right size.

I have some silicony goop here - 'Moto Seal' - that's intended for places that would need disassembled. Made for things like carb bowls & whatnot. I use a dab of it, on my union faces for some added insurance - I always found those things to want to seep a bit sometimes. Haven't had a leaking union since I started doing it. So maybe some of that on the gasket also?

 

[Nofossil]

Are all flanges flat?

The flanges on the pipes are flat, but the mating flanges build into the circulator body have square grooves for a compression ring.

The combination of flat flanges, and EPDM gasket, and some goop seems like a good option - I'm just hoping someone can confirm that it will work.

I like the idea of using sweat copper to fine-tune the length. Easier for me than black iron for sure.

I've also though about removing the impeller from a dead circulator and just bolting that in place, but I'm afraid of flow restriction.

 

[Buzz Saw]

NofossiI, don't see why your idea wouldn't work. Any brand silicon plumbers lube should do the trick to help make a good seal.

Sent from my SM-G950U using Tapatalk

 

[TCaldwell]

I’ve done it both ways described, the male copper adapters threaded into the circ flanges with the copper pipe in between gives more wiggle room when setting up. A safer way is to sweat say a 4 inch piece of pipe on each male adapter, let them cool, thread each into the respective flange, measure the total length of the assembly and trim each copper pipe so there is a joint in the middle, use coupler that doesn’t have stops. Bolt each flange up, center the coupler and sweat. This way the sweat joint is far enough from the pipe dope. I have used reg flat circ gaskets without a problem

 

[Nofossil]

.....and trim each copper pipe.....

I like it, except I think I'll trim just one ;-)

Thanks for the voice of experience using flat gaskets. I think I'll actually assemble and sweat all but the last joint on the coupling, assemble and bolt in place, then sweat the last joint.

 

[Fred61]

Being a former shade tree mechanic in my teen years, I have always assumed that anyone who has ever picked up a wrench had a roll or two or three gasket material of in the tool box. At one time you could go to the auto parts store and pick up a roll of gasket material. Perhaps that cannot be done anymore. If not I'll closely guard my stash. Can't recall how many times I screwed up a thermostat gasket and had to make a new one. Just laid the material on the casting and formed the shape with a ball peen hammer.

 

[Nofossil]

Just laid the material on the casting and formed the shape with a ball peen hammer.

Been there, done that, *and* have the T-shirt ;-)

My assumption is that boiler plumbing stresses gaskets in a slightly different way, so my initial thought was that EPDM would provide a bit of 'give' when pipes expand and contract - not something that an automotive water pump casting experiences in the same way. To make matters worse, the flange faces are not as nicely machined as automotive parts are. In any event, my stash of automotive gasket material is long gone.

Of course, I think I remember that you're almost local. Maybe trade some homebrew for a gasket?

 

[Hydronics]

Unless I'm missing something in your description - I made one with circulator flanges and a steel pipe nipple, I used the pre-made circulator gaskets between and had no issues. Use a good amount of Teflon on the threads so you have adjustability for length when tightening the nipple to flanges.

 

[Fred61]

I think the gasket material should work. When the two flanges are bolted together the two become one. I would rather work with gasket material than a squigly piece of rubber. remember Permatex, that goop we applied to the gaskets to help seal the joint. Probably can't get that anymore either but there's always pipe dope. No, not my plumber! The stuff in the can. It will help fill any porosity in the castings.

I can't see where you would gave any more trouble installing a straight pipe in place of the circ assuming you get your dimensions accurate.

I checked and do have some gasket material that I can give up. PM me your address and I'll get it out to you. It will be skinny. I traced a couple Taco flanges on to it and will cut it off fairly close.

 

[Bad LP]

In my former life I was a maintenance machinist at BASF Systems and Loctite made a product called static O ring. Sort of like silicone gasket sealer but better. Perfect for use with flanges.

 

[Bob Rohr]

You can also buy sweat type flanges, saves using adapters in threaded flanges.

 

[salecker]

How about cutting the flanges off an old pump,then welding in a piece of iron pipe to replace the pump housing.
You would then have a iron pipe with o ring flanges.Pressure test the welds,then bolt in place of your pump.

 

[Nofossil]

OK - here's my current thoughts:

The circulator is pretty short - not enough room for a center slip fitting. I'll use a pair of flat flanges with gaskets gooped with sealant:

existing flange
gasket
iron female npt flange
brass close nipple
copper fnpt-sweat
copper pipe
copper fntp-sweat
brass close nipple
iron female npt flange
gasket
existing flange

I'll dry-fit and make the copper pipe just a bit shorter than the stackup would indicate. I'll then reassemble and solder in place.

Long ago in my mis-spent youth I learned at the feet of a wise and grizzled old plumber that you never thread copper into iron - hence the brass close nipples. Is this still the accepted wisdom?

 

[Fred61]

Gasket material is in the mail!

 

[Nofossil]

Gasket material is in the mail!

Thanks - much appreciated.

 

[Hydronics]

OK - here's my current thoughts:

The circulator is pretty short - not enough room for a center slip fitting. I'll use a pair of flat flanges with gaskets gooped with sealant:

existing flange
gasket
iron female npt flange
brass close nipple
copper fnpt-sweat
copper pipe
copper fntp-sweat
brass close nipple
iron female npt flange
gasket
existing flange

I'll dry-fit and make the copper pipe just a bit shorter than the stackup would indicate. I'll then reassemble and solder in place.

Long ago in my mis-spent youth I learned at the feet of a wise and grizzled old plumber that you never thread copper into iron - hence the brass close nipples. Is this still the accepted wisdom?

The logic being reduced risk of galvanic corrosion. Brass is a bit closer (more noble/anodic) to iron than copper.
Just a suggestion: you could save some work and expense if you used sweat flanges only and copper between them.

 

[Fred61]

The logic being reduced risk of galvanic corrosion. Brass is a bit closer (more noble/anodic) to iron than copper.
Just a suggestion: you could save some work and expense if you used sweat flanges only and copper between them

All reactions greatly reduced with boiler water that is depleted of oxygen.

 

[Bob Rohr]

I have a bunch of copper jumpers mad up, be glad to mail you one.

Dis-similar meals really isn't a concern in closed loop hydronics. The O2 becomes depleted quickly and there should be no corrosion. Many cast iron boilers have copper screwed into them or the cast iron circulators.

 

[Nofossil]

Well, I have the brass nipples and I don't have a good source for sweat flanges - iron threaded flanges on order. Thanks for all the advice. For future reference, though - where can I get sweat flanges?