Help Modifying 2 Pipe Hydronic Radiator Line

[Europe72dead]

I’m in the process of relocating a cast iron radiator and will be running Uponor hePex to the new Runtal Cast Iron Radiator. I’m planning on using all brass fittings including a brass nipple as a riser to the radiator shutoff valve.

The Runtal valve is nickel plated brass so I’m most concerned with mixing metals by transitioning from original black pipe to brass pex transition fitting. Because this is a closed loop system I believe I’m fine but wanted some assurance. Thanks!

Is there anything wrong with this setup?

 

[Fitter30]

There's no problems with mixing material. Valves are brass. With system drained good time to put in some boiler treatment and if you have a bladder tank check the air charge.

https://www.amazon.com/Rectorseal-68712-Quart-Boiler-Treatment/dp/B008A3UEA0/ref=mp_s_a_1_5?adgrpid=1346902310800703&dib=eyJ2IjoiMSJ9.PjtmgeQHS8-mhk_FT8louJ7e18aaZpMLuiemoxtGu1Re5uNfut9gHvP0K9CT_JCkS-brRNCdow5kIzDb952N_Qgu4GRUPyggVON8rmIEc5r252VARhAOPcBmQZUBJ_3CgvYvVwZJO9rdHfZiCckh030B9EDnjZoMMAnaEQKC50gOSKusFDzRxB68ZKXYkLNLhik1DHAa2UFTtRcY9u98lA.VPKVu45BXnAqczXAS9CdaM4RHo05tye6xdVcc1WXjvg&dib_tag=se&hvadid=84181543767848&hvbmt=bb&hvdev=t&hvlocphy=85016&hvnetw=o&hvqmt=b&hvtargid=kwd-84181744474666%3Aloc-190&hydadcr=24662_13493378&keywords=boiler+liquid&mcid=a334f998f3d43207bec4fdf6d0be3996&qid=1745334944&sr=8-5

 

[Sponsor]

 

[John Gayewski]

Looks fine to me.

 

[cdherman]

Key is using pex with an oxygen barrier, which the Wirsbo has.

One warning -- pex expands a LOT more than steel or copper. If you have bends or tight spots where you go through wood, you could get more popping and expansion sounds when the temp is changing (ie, when you call for heat). If you have continuously variable termostatic heads on the radiator, and a constant flow design, less of problem. But if you have a zoned system with thermostats, you can get noise. Ask me how I know......

 

[Sylvan]

Key is using pex with an oxygen barrier, which the Wirsbo has.

One warning -- pex expands a LOT more than steel or copper. If you have bends or tight spots where you go through wood, you could get more popping and expansion sounds when the temp is changing (ie, when you call for heat). If you have continuously variable termostatic heads on the radiator, and a constant flow design, less of problem. But if you have a zoned system with thermostats, you can get noise. Ask me how I know......

You're right, the coefficient of expansion per degree of Cast Iron and PEX can be a problem

I'm on a case now where the system was black steel schedule 40, and he used copper to connect a CI radiator on a long run.

No expansion loops, and the copper ruptured, causing massive damage, plus the death of an 11-month-old baby in Brooklyn

11-month-old boy dies after apparent burn from steam radiator in Brooklyn home

The 11-month-old was sleeping in his room when a radiator malfunctioned and sent scalding steam into the room.

abc7ny.com