# Cast Iron Radiator Connector Fitting



## Eric Johnson

I just picked up a couple of old cast iron radiators from a neighbor's "remuddling" project, and I'm trying to figure out how to use the standard connectors that they're plumbed with. In the past, I've simply removed these old brass fittings and installed standard black iron or copper fittings into the standard-thread bushings already in the rad, but since these are in good shape and it would be a lot less work just screwing a fitting into what's already there, I'd like to give that a try.

However, they don't accommodate a standard 3/4-inch fitting. The threads are somewhere between 3/4" and 1". I read somewhere (I think) that I what I need are "angle unions" which, judging by most of the other radiators in my house, are a kind of special street 90. No clue where to score such a piece.

Any thoughts? I plan to put 3/4-inch ball valves on these rads instead of conventional radiator-specific gate valves, so I need to reduce the line to a standard 3/4-inch pipe thread at some point.

I can post pics, but won't unless somebody needs to see precisely what I'm talking about.

These rads would replace HW baseboards in my mom's farmhouse, BTW, which I find to be pretty worthless and ugly, to boot. Nothing like a solid mass of cast iron and hot water on a cold winter morning to warm body and soul, IMO.


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## woodsmaster

If you cant find anything to fit maybe you culd have a machine shop make somthing ?


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## Eric Johnson

Easier and cheaper just to remove the odd fittings and screw something standard into the standard bushing.


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## Eric Johnson

Here's what it looks like:







This is what I think I need.





And here's how I typically do it.


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## slim

Replace copper piped baseboard with cast iron radiators? Rust?


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## Eric Johnson

slim said:


> Rust?


 
Rust? Rust from where?


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## salecker

Hi Eric
 I was told that a ball valve may erode if its used to regulate flow.Havn't seen one that has eroded.
 Just thought i'd mention it.
 Thomas


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## Clarkbug

I think you are right on the fitting that you are looking for.  I was given a few old radiators, and they had that same angle union fitting.  I cant find anything that will mate up to it, so Im going to have to try and just back the old thing out and put in new bushings/fittings.


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## Eric Johnson

I've backed a few out and cut a few out. You can do a lot if you have a big enough wrench.


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## raybonz

Not trying to hijack but WOW Eric I haven't seen you here in eons! Welcome back!

Ray


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## Eric Johnson

raybonz said:


> Welcome back!


 
Thanks, Ray. I've been distracted by health issues, unfortunately. Not dead yet (but we're working on it).

Anyway, I'm still cutting firewood and heating with same. Still fooling around with hydronic heating systems. I like the woodshed in your avatar, BTW.


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## raybonz

Eric Johnson said:


> Thanks, Ray. I've been distracted by health issues, unfortunately. Not dead yet (but we're working on it).
> 
> Anyway, I'm still cutting firewood and heating with same. Still fooling around with hydronic heating systems. I like the woodshed in your avatar, BTW.


Well I hope you're on the mend Eric.. Thanx for the wood shelter comment! I just posted on another member's shelter which came out better and had a few improvements over this one.. Thinking a wood shelter picture area would be helpful to forum members that are thinking of building one..

Ray


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## Eric Johnson

Here's the answer.

http://www.heatinghelp.com/forum-thread/141537/Angle-Union-for-Cast-Iron-Rad-Connection

I pulled the 1 1/4 inch plugs and will replace them with standard 1 14/ to 3/4 reducer bushings. They weren't hard to get out with a 24-inch pipe wrench. I think I'll plumb the visible parts in black iron and make the copper connections below the floor. It will look better, I think, and provide a bit more stability.


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## heaterman

salecker said:


> Hi Eric
> I was told that a ball valve may erode if its used to regulate flow.Havn't seen one that has eroded.
> Just thought i'd mention it.
> Thomas


 

They do. I have about 100 pounds worth in a box in my shop, (going to melt them down to make a cannon ) None of them will close off completely because the bottom of the valve plate is worn off.

A globe valve is best for throttling flow. A circuit setter is the ultimate but pricey.


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## Eric Johnson

Any idea why that would be? What's different between a hydronic line leading into our out of a cast iron radiator and any other location on the system? I've put ball valves on rads before, but I never use them to modulate the flow. It's more of a shutoff/isolation arrangement than anything else, though (to my mind) it certainly could be used to control heat output--probably even if the ball leaks..


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## maple1

I think the point is no matter where used (on a cast rad or not), the erosion will occur when a ball valve is used for throttling. They're not exactly designed for partially-open throttling, more for on/off. As I see it.


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## Eric Johnson

I see. That's ironic, given that one of the big advantages of ball valves is that you can see what they're set at from halfway across the room, vs. gate valves, etc., which need to be turned to figure out how they're set--and even then you're not completely sure, especially with older installations and those piped into fresh water systems and other applications prone to corrosion.

Of course, if the ball is eroded, then I guess the handle location doesn't tell you as much about the valve as you'd like to think.


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## flameretardant

I got 15mm TRV's on my cast rads. It was impossible to find metric fittings/adapters so I had a machinist ream the valves to 5/8 inch. They were compression fittings so there is some leeway on fit. No leaks. And mixing copper and iron is a BAD idea. You WILL get corrosion. Fortunately, the cast rads can take a fair bit of corrosion. Hope you have a good sediment trap on your return.


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## Eric Johnson

Interesting point about dissimilar metals. Every house I've owned for the past 25 years or more has had hydronic heating systems mixing copper and cast iron, including my current setup which has a 54 year-old cast iron gas boiler extensively piped with copper. But I'm sure it wasn't originally. The one place I did own with all black iron (except for the brass valves, which I assume don't count) had a fine, black powder deposit on the inside of the pipes and rads and kind of a fishy smell. I'm trying to think what the other places' interior piping looked like, but I don't think they'd be considered rusty, at least to a noticeable degree. But the deposits are different, and I suspect there is a degree of corrosion going on in the mixed systems, as you say.

Pex seems to be replacing plenty of copper these days, which is probably just as well, considering the cost of metals.


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## maple1

Disagree on iron + copper = corrosion.

In a sealed/pressure system, at least.


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## Eric Johnson

Here's how I've got it plumbed up (and pressure tested). I'm going through the floor with black iron for stability (small rad on an uneven floor), but will put isolation valves and drain down below and either connect it to pex or copper.


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## flameretardant

maple1 said:


> Disagree on iron + copper = corrosion.
> 
> In a sealed/pressure system, at least.


 
Got anything to back that up? Did a salvage on a copper/iron system. The steel panels failed en masse in 3 years. All iron parts showed extensive grooving that worsened as it approached copper. Closed system. Water tests were fine. No excessive make-up was reported. Also, chemistry: Copper + iron/steel + water = galvanic cell = transfer of electrons = corrosion.


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## maple1

Just doing maintenance on my own boiler. I've had to disassemble some copper/iron connections, everything looked A-OK inside after 15 years or so. Copper + galvanized fittings I would say to be a different story.


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## woodsmaster

I don't have any data but I was told that my steel panel rads shouldn't be plumbed with copper so I used pex.


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## coaly

The part you have is on the left.  The elbow that mates to it is on the right. Pictured above is the tool that goes inside the union to remove the nipple from radiator. You will notice two raised nubs inside the fitting that the tool comes up against to turn it out. They went by thread size, not the union straight thread. (non tapered) Before anything was standardized, the threads could be different from mfg. to mfg. I run into Imperial threads on steam stuff too. Mostly Canadian locomotives.
These are new old stock. I bought up a garage full of plumbing parts from a retired plumber that did a lot of steam work.
 When using a new piece that wasn't an original mate, you put a dab of valve grinding compound on the ball joint (the mechanical joint) and work it back and forth to lap them together for a steam tight joint. When you find one of us steam collectors with traction engines, road rollers and what-not, you'll find we aquire house parts in buckets of stuff we hang onto just in case. I have many like this with an adjustible shutter valve inside too.

 The bushings used on radiators in old homes had fancy markings like twisted ropes, dots, hash marks.......... so back in the day, the entire building matched ! It was an art back then that has been lost.

  I collect these bushings when I find them, and have a bucket full of all different designs. Just one of each, but quite a collection. I've always said "look long enough, you'll find someone that collects anything".


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## Eric Johnson

I totally agree on the works of art opinion, coaly. And yep, some of those bushings are pretty elaborate. Pretty outrageous designs cast into some of those old rads and you're right, having a complete set in any house is worth a lot.


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## coaly

Here's a few of the adjustible type with shutters inside to balance flow; They come in straight and Tee too. To give you an idea of size, they are sitting on a 10 inch stove lid.

The one on the right has a drain petcock with mount ears.

I have buckets of these things, including brass railing parts. Too cool to scrap !  I bought the lot for Lunkenheimer parts, steam relief valves, whistles, and oilers. It came with a bench type threader, portable pipe vice on a long pipe with adjustable top to take into a basement and tighten against a floor joist llike a post, pipe vices that have a strap affair to prevent marring chrome and brass pipe, and large pipe cutters like a chain wrench with cutter wheels all the way around that cuts well casing and larger pipe very easily. $200 for the entire garage full in the 80's. Most of the stuff was from the 1920's and 30's. I bought it for the stuff from the 1800's ;

.


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## coaly

Ah, old fittings have captured my attention for quite some time.
I call this stuff my "dead men collection" since most people that used them when new are dead.
Could there be anyone else with a ornate bushing collection?



Or these early type brass fittings with holes to melt lead or solder into a groove inside the fitting? I don't collect used ones taken from homes, only unused new old stock.




With the lot I bought was a bunch of these plugs on the bottom shelf, made with a large wing nut to bulge the rubber plug open for possibly pressure testing or draining large lines ??   I know what the pump parts are on the right, but these things are a mystery.


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## guy

Eric Johnson said:


> I just picked up a couple of old cast iron radiators from a neighbor's "remuddling" project, and I'm trying to figure out how to use the standard connectors that they're plumbed with. In the past, I've simply removed these old brass fittings and installed standard black iron or copper fittings into the standard-thread bushings already in the rad, but since these are in good shape and it would be a lot less work just screwing a fitting into what's already there, I'd like to give that a try.
> 
> However, they don't accommodate a standard 3/4-inch fitting. The threads are somewhere between 3/4" and 1". I read somewhere (I think) that I what I need are "angle unions" which, judging by most of the other radiators in my house, are a kind of special street 90. No clue where to score such a piece.
> 
> Any thoughts? I plan to put 3/4-inch ball valves on these rads instead of conventional radiator-specific gate valves, so I need to reduce the line to a standard 3/4-inch pipe thread at some point.
> 
> I can post pics, but won't unless somebody needs to see precisely what I'm talking about.
> 
> These rads would replace HW baseboards in my mom's farmhouse, BTW, which I find to be pretty worthless and ugly, to boot. Nothing like a solid mass of cast iron and hot water on a cold winter morning to warm body and soul, IMO.


 just logged on ,did you ever get those radiators converted?You need to cut and break the old fitting out.


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## Mark Holden

Regarding corrosion; I studied it a little in the past.
Dissimilar metals will cause a galvanic cell to form and cause corrosion, but remember that corrosion is almost entirely oxidization; when the oxygen runs out [in a sealed system] the corrosion stops.
There are exceptions; stainless steels will corrode without oxygen, but are happy in the presence of oxygen. aluminum will combine with anything.
I've seen the same thing with ball valves; it could be crevice corrosion on the stainless balls due to the lack of oxygen. When fully open, the ball surfaces are protected, you'll never notice a bit of loss in the bore.
Or it could be turbulence [or erosion] corrosion, caused by high water velocity. I believe this is caused by electrical current being generated by the swirling water in the fitting. It's noisy too.

Coaly, good info on old pipe fittings! It's a constant learning process for me. Valve compound... how come I didn't know that? Good tip.
Here in Europe they've moved to straight threads [terrible to seal] but old fittings and some imported stuff has taper threads. BSP, NPT... it's a mess.
I've managed to collect pipe taps from 1/8" to 1", very handy.


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## Eric Johnson

I was able to back the original 1 1/4-inch brass fittings out without too much trouble, and I replaced them with 1 1/4 to 3/4-inch reducers and piped it through the floor with black iron going into copper down below. Carried the thing from NY out to Wisconsin in the truck of the family Jetta. It looks really nice in the kitchen--a lot nicer than that old, crummy hydronic baseboard. I assume once winter rolls around, it will heat the space a lot better, too. I'm color blind, so I bought dark brown spray paint instead of black, and didn't notice until it was dry, but Mom says she likes it better anyway.


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## Rob186

Wow a spud wrench you dont see them to often i am a pipe fitter and have changed thousands of steam rads to hot water and the best advise on removing spuds is lots of PB blaster a d a prayer to the pipe gods lol most of the time they are so frozen that the nubs break off  so I tap the spud wrench in and put a pipe wrench on it the spud wrench keeps the fitting from egging


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## Rob186

Oh forgot to add never throdel with a gate valve you will we're out the seats a d it wolnt be a positive shut off when you need it


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## wardk

coaly said:


> Here's a few of the adjustible type with shutters inside to balance flow; They come in straight and Tee too. To give you an idea of size, they are sitting on a 10 inch stove lid.
> 
> The one on the right has a drain petcock with mount ears.
> 
> I have buckets of these things, including brass railing parts. Too cool to scrap ! I bought the lot for Lunkenheimer parts, steam relief valves, whistles, and oilers. It came with a bench type threader, portable pipe vice on a long pipe with adjustable top to take into a basement and tighten against a floor joist llike a post, pipe vices that have a strap affair to prevent marring chrome and brass pipe, and large pipe cutters like a chain wrench with cutter wheels all the way around that cuts well casing and larger pipe very easily. $200 for the entire garage full in the 80's. Most of the stuff was from the 1920's and 30's. I bought it for the stuff from the 1800's ;
> 
> .
> 
> 
> 
> 
> 
> 
> 
> 
> 
> View attachment 68963


I have one of the shutter valves I would like to reuse if I can seal it, the packing seal was almost gone do you think an O ring would work?


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## Nicholas Geti

wardk said:


> I have one of the shutter valves I would like to reuse if I can seal it, the packing seal was almost gone do you think an O ring would work?


 
The usual packing that one can get locally is some kind of string. It fails totally to stop leaking. I found a Teflon Valve Stem Packing (1/8" dia corded Teflon) that worked well. I had to ask a local plumbing supply to order it for me from http://www.gore.com/en_xx/products/sealants/packing/packing.html


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## Nicholas Geti

Mark Holden said:


> Regarding corrosion; I studied it a little in the past.
> Dissimilar metals will cause a galvanic cell to form and cause corrosion, but remember that corrosion is almost entirely oxidization; when the oxygen runs out [in a sealed system] the corrosion stops.
> There are exceptions; stainless steels will corrode without oxygen, but are happy in the presence of oxygen. aluminum will combine with anything.
> I've seen the same thing with ball valves; it could be crevice corrosion on the stainless balls due to the lack of oxygen. When fully open, the ball surfaces are protected, you'll never notice a bit of loss in the bore.
> Or it could be turbulence [or erosion] corrosion, caused by high water velocity. I believe this is caused by electrical current being generated by the swirling water in the fitting. It's noisy too.
> 
> Coaly, good info on old pipe fittings! It's a constant learning process for me. Valve compound... how come I didn't know that? Good tip.
> Here in Europe they've moved to straight threads [terrible to seal] but old fittings and some imported stuff has taper threads. BSP, NPT... it's a mess.
> I've managed to collect pipe taps from 1/8" to 1", very handy.


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## coaly

You measure the "packing space" between shaft and outer bore. This is the packing diameter you need. Each wrap is it's own ring. The correct way is with a wood dowel the same size as shaft to cut it on. Wrap around the dowel one turn, and where it overlaps, cut with a razor knife on a 45* angle. Also hold the blade on a 45* like a compound mitre saw cut. As you 'stack' them on the shaft, keep the cut ends at different positions to overlap the cuts. When they wear, or crush, you simply add another ring. There is a corkscrew type tool used (packing puller) to remove rings down to a good one, so you don't normally replace all at once. The black graphite impregnated provides lubricant, and expands when heated to be steam tight. This is how packing is done on sliding steam valves on engines, as well as rotating valve stems.
There is also packing material made with a V on the sides. When stacked on each other, the space between them isn't straight to allow steam to leak between them. This is called chevron packing. (stacked up, the joints look like the old Chevron sign)


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## Nicholas Geti

Mark Holden said:


> Regarding corrosion; I studied it a little in the past.
> Dissimilar metals will cause a galvanic cell to form and cause corrosion, but remember that corrosion is almost entirely oxidization; when the oxygen runs out [in a sealed system] the corrosion stops.
> There are exceptions; stainless steels will corrode without oxygen, but are happy in the presence of oxygen. aluminum will combine with anything.
> I've seen the same thing with ball valves; it could be crevice corrosion on the stainless balls due to the lack of oxygen. When fully open, the ball surfaces are protected, you'll never notice a bit of loss in the bore.
> Or it could be turbulence [or erosion] corrosion, caused by high water velocity. I believe this is caused by electrical current being generated by the swirling water in the fitting. It's noisy too.
> 
> Coaly, good info on old pipe fittings! It's a constant learning process for me. Valve compound... how come I didn't know that? Good tip.
> Here in Europe they've moved to straight threads [terrible to seal] but old fittings and some imported stuff has taper threads. BSP, NPT... it's a mess.
> I've managed to collect pipe taps from 1/8" to 1", very handy.


 


Eric Johnson said:


> I was able to back the original 1 1/4-inch brass fittings out without too much trouble, and I replaced them with 1 1/4 to 3/4-inch reducers and piped it through the floor with black iron going into copper down below. Carried the thing from NY out to Wisconsin in the truck of the family Jetta. It looks really nice in the kitchen--a lot nicer than that old, crummy hydronic baseboard. I assume once winter rolls around, it will heat the space a lot better, too. I'm color blind, so I bought dark brown spray paint instead of black, and didn't notice until it was dry, but Mom says she likes it better anyway.


 

I have a cracked brass elbow fitting for a cast iron radiator. It is many years old. I took it to a local supply house to get one like it and found that modern fittings even made by the same mfg have a different flare angle and face-to-face distance. I can either buy a spud wrench and add new fittings or find someone who has the antique style willing to sell me one.

I have tried to keep my 200 yr old house authentic and am reluctant to replace any more than I have to.


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## coaly

Practice a bit with a brazing rod and torch on old brass fittings. You'll get good enough to melt it on like solder and repair your old fittings. A little hand machining and you're fittings are usually useable.


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## wardk

Nicholas Geti said:


> The usual packing that one can get locally is some kind of string. It fails totally to stop leaking. I found a Teflon Valve Stem Packing (1/8" dia corded Teflon) that worked well. I had to ask a local plumbing supply to order it for me from http://www.gore.com/en_xx/products/sealants/packing/packing.html


I found graphite packing at the local plumbing wholesaler , couple wraps doesn't leak a drop,they also had a sweet copper air extractor works great.


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## Nicholas Geti

wardk said:


> I found graphite packing at the local plumbing wholesaler , couple wraps doesn't leak a drop,they also had a sweet copper air extractor works great.


 
I visited most of the suppliers between Danbury, CT and Bridgeport, CT. No one had graphite packing which is why I tried the Teflon. Where did you buy yours?


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## Nicholas Geti

coaly said:


> Practice a bit with a brazing rod and torch on old brass fittings. You'll get good enough to melt it on like solder and repair your old fittings. A little hand machining and you're fittings are usually useable.


 
Are you talking about an acetylene type of torch or the plain, propane cylinder that people use for soldering copper pipe? The first one sounds like it would require heavy duty equipment and a skill I don't have.

Nick Geti


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## raybonz

Nicholas Geti said:


> I visited most of the suppliers between Danbury, CT and Bridgeport, CT. No one had graphite packing which is why I tried the Teflon. Where did you buy yours?


In the electrical trade we call rope packing monkey $hit 

Ray


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## wardk

Nicholas Geti said:


> I visited most of the suppliers between Danbury, CT and Bridgeport, CT. No one had graphite packing which is why I tried the Teflon. Where did you buy yours?


It was at B.A. Robinson Kamloops B.C. just hanging on the wall with all the tap repair parts Oring , cartridges, washers Etc.If I can find the package I'll let you know the brand and part #.


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## wardk

Nicholas Geti said:


> I have a cracked brass elbow fitting for a cast iron radiator. It is many years old. I took it to a local supply house to get one like it and found that modern fittings even made by the same mfg have a different flare angle and face-to-face distance. I can either buy a spud wrench and add new fittings or find someone who has the antique style willing to sell me one.
> 
> I have tried to keep my 200 yr old house authentic and am reluctant to replace any more than I have to.


IMHO I'd be more worried about water staining a 200 yr old floor than using a modern fitting.


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## Nicholas Geti

wardk said:


> IMHO I'd be more worried about water staining a 200 yr old floor than using a modern fitting.


 
No problem. The floor is 18" wide poplar planks which I sanded and coated with urethane colored very lightly with several stains to get a uniform color between the boards. It is gorgeous. The finish is very hard and can take any kind of punishment.

I still want to be consistent between brass fittings. In any case I have Googled and cannot even find a simple, modern valve and elbow. I ordered a spud wrench just in case I need to swap out the tail pieces.


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## Nicholas Geti

raybonz said:


> In the electrical trade we call rope packing monkey $hit
> 
> Ray


 
Do you really expect me to say that when I go shopping?


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## raybonz

Nicholas Geti said:


> Do you really expect me to say that when I go shopping?


Yes, tradesmen say this and they will understand it.. Just like peckerhead is a motor J-box or duck $hit is duct seal or channel locks are water pump pliers.. need I go on?

Ray


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## Couderay80

Eric Johnson said:


> Here's the answer.
> 
> http://www.heatinghelp.com/forum-thread/141537/Angle-Union-for-Cast-Iron-Rad-Connection
> 
> I pulled the 1 1/4 inch plugs and will replace them with standard 1 14/ to 3/4 reducer bushings. They weren't hard to get out with a 24-inch pipe wrench. I think I'll plumb the visible parts in black iron and make the copper connections below the floor. It will look better, I think, and provide a bit more stability.


 
Thats fine, when you go from black pipe to copper put a brass fitting in between the two like an union or valve. Brass ball valve is fine for throttling not my first choice but better than a poke in the eye with a sharp stick. That fitting in your rad. was exactly that and old collar for a union.


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## heaterman

salecker said:


> Hi Eric
> I was told that a ball valve may erode if its used to regulate flow.Havn't seen one that has eroded.
> Just thought i'd mention it.
> Thomas


 
Proper valve for flow regulation is a globe valve.


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## Couderay80

heaterman said:


> Proper valve for flow regulation is a globe valve.


 
Most circuit setters are ball valve type and have been around for along time.I agree its not the best choice but if I had to choose would go with a ball valve over a globe each and every time. In all the piping I've done over the years ball valves far out number globes, are cheaper, and dont seem to plug up as bad. Again not the best but does a good job in regulating the flow. Just ask any installer what they use to regulate the flow, ball valves far outnumber globes, at least in all the years I've been pipefitting.


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