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IPS header fitting leaks

JamieLeef Member Posts: 13
I have a vexing problem on a pressurized glycol system in the Boston area. All of the 1" NPT fittings of my SunMax VHP tube collector headers are leaking - a slow weeping drip. None of the other threaded connections leak in the system, just those at the headers. I have attached either copper female adapters, brass 1" threaded couplings, or brass female unions screwed onto these header nipples - all three types leak in the same way. And even with the couplings it is only the header side not the other side of the fitting. I originally used just Loctite 580 on them, then took it all apart and used blue teflon and high-temp dope. Same leak. Any thoughts? SunMaxx just says dope and blue teflon. And avoid over-tightening. I have lots of systems and lots of IPS connections with no other problems. Is this a known SunMaxx issue?



  • hot_rod
    hot_rod Member Posts: 22,258

    Is it a gasketed connection, or just threaded?

    dis-assemble, clean and dry the threads and use a loctite 272. This is a high temperature thread sealent. Not all Euro machined NPT threads seal well. They sometimes try to taper or modify a BSP, or machine a NPTF. Glycol is a tough fluid to seal, "gluing them together with loctite is a workable option. Give it 15 minutes or so to set before you re-fill and pressurize the system.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream