Cast Iron baseboard leak on strange fitting

castiron1790

I have an older home with cast iron baseboard. I found a leak on a strange looking fitting. Can I replace this fitting with a normal peice of 3/4 copper? What is the point of this fitting?

Grallert

Looks like an expansion coupling. Looks like a bad idea. Should be a simple repair with a couple of couplings and a length of pipe.

hot_rod

A # 75 SlantFin expansion coupling, I'll bet. They come across E bay from time to time.

Screenshot 2025-02-01 at 3.40.34 PM.png

EBEBRATT-Ed

Expansion joint. How long is the pipe run? I doubt they installed it for no reason

castiron1790

there are two of these joints both are leaking, both at the beginning of the run. The water comes up from the basement then splits at a tee fitting on the second floor, About two feet from the t fitting are these joints. Each run goes around the perimeter of separate bedrooms then back down to the basement.

Long Beach Ed

How long is the pipe it's on?

castiron1790

Coming off the tee, The pipe is about 3 foot long before it goes into the cast iron baseboard.

hot_rod

You should be able to see how much the tube is moving by the scale around the outside.

an expansion loop can be built with 4 ells also.

castiron1790

https://forum.heatinghelp.com/discussion/comment/1839626#Comment_1839626

so these should not be eliminated with straight pipe but replaced with new expansion fittings?

hot_rod

https://forum.heatinghelp.com/discussion/comment/1839644#Comment_1839644

it depends on the overall length of that section. The piping and baseboard combined.

Without an expansion joint you may get noise, creaking, snap, crackle pop type noises as the metals heat and expand and try to grow in length.

Long copper fin tube sections will arc up off their supports if you don’t accommodate the expansion movement.

There are other types of expansion joints like a corrugated section. Viessmann use to have a short corrugated coupling that went between their solar hot water panels. I think it was a metric size however

I wonder what the temperature rating is on these water heater connectors? I think it would offer enough flexibility.

IMG_1019.jpeg

delcrossv

Bellows type is still available.

Much better than a slider joint.

https://www.flexicraft.com/Metal_Expansion_Joints/Copper_Piping_Expansion_Compensator_S/

Larry Weingarten

Hi, What temperatures is this seeing? Perhaps a loop of PEX would do the job.

Yours, Larry

EBEBRATT-Ed

Larrys pex solution is probably the simple best solution if the temp is ok for the pex

delcrossv

https://forum.heatinghelp.com/discussion/comment/1839670#Comment_1839670

With more connectors? What's wrong with a compensator? 2 sweat joints and you're done.

Intplm.

A lot of good ideas. Fostapex has a top temp rating of around 200Deg. f. . If it was me I would replace the expansion joints with a length of that.

pecmsg

https://www.supplyhouse.com/Parker-Hannifin-475447-VAB7SS-7-8-ODF-Vibration-Absorber?utm_source=google_ad&utm_medium=Shopping_HVAC&utm_campaign=Shopping_X_HVAC_X_SSC_ClassB/C&utm_campaignid=21633352527&utm_adgroupid=164986448125&utm_targetid=aud-386072062457:pla-2352433400835&utm_product_id=475447&utm_matchtype=&utm_keyword=&utm_adtype=pla&utm_category=HVAC&gad_source=1&gbraid=0AAAAAD_WAytSArjNTgjqdKLzFSkR2w6t_&gclid=CjwKCAiAzPy8BhBoEiwAbnM9OwC63tVi6cAUJjR5aAP3f6-fq9NLqu2BfKqW4gFK59T3h3oA8o1TahoCEyMQAvD_BwE

delcrossv

https://forum.heatinghelp.com/discussion/comment/1839710#Comment_1839710

Not heat rated.

pecmsg

It will handle 180°F water.

McMaster Carr lists it at -300 - 1200°F

castiron1790

https://forum.heatinghelp.com/discussion/comment/1839670#Comment_1839670

around 180F

castiron1790

thanks for the help fellas, put in a small expansion loop, no leaks and no popping sounds like before.