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Coupling copper to steel pipe

Jeff Elston
Jeff Elston Member Posts: 289
Use some GruvLok

check it out some ideas

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  • greg_30
    greg_30 Member Posts: 8
    coupling 4\" copper to 4\" steel pipe

    Here is the project. We are installing a new atmospheric, water tube hot water boiler (ray-pak, 1223 MBH input, nat. gas. ) on an old system that has 4" steel pipe. The plan is to create a primary-secondary loop system. We will remove the old boiler and pipe the 4" in/out together (in a sence, bypassing the old boiler) creating the secondary loop that circulates the building. In this bypass we will place two closly space tees for connection to our new primary loop and boiler. Question: the old piping is steel, we hope to use copper for the 4" bypass and 2" copper for the primary loop. We want to couple 4" steel to 4" copper. We want to avoid reactions between the dissimilar metals. It seem because of the large pipe diameter we may have to use 4" flanges with isolation gaskit kits. Any suggestion on this connedtion?
  • hvacfreak
    hvacfreak Member Posts: 439
    Malony Kit

    We call them " Malony Kits "..flange kit with plastic sleeves and non metallic washers for the hardware.
  • rich pickering
    rich pickering Member Posts: 277
    Closed system?

    I'm sure others will chime in, but corrosion shouldn't be a problem in a closed system.

    Did a similar job last winter, we used groved fittings and 2 Knghts.
  • Rich Kontny_4
    Rich Kontny_4 Member Posts: 73
    I'.m With...

    HVAC freak on this one,the Maloney kits as he calls them are designed for di-electric style applications. While corrosion is not usually an issue this sounds like a large system that will most likely use make up water. The makeup water adds oxygen to the system and possibilities of corrosion.

    Also these companion flanges act as a union and are more forgiving than lets say a 4" female adapter. Large copper and brass fittings can be distorted when tightened increasing the probability of leaks.

    Rich Kontny
  • [Deleted User]

    Their 4" fittings are brass, a known neutral in disimilar metal connections.

    If you don't own a tool, surely you can rent one from a contractor that does.

This discussion has been closed.