Heat exchanger end caps

Jane-O · Member

Heat exchanger end caps

Farron · Senior Member

Hello Jane-O,

What you have described is normal. The sealing takes place between the o-ring and the 3 sealing surfaces of the tube stack, heat exchanger body and the cap itself.

It is not required that the base of the cap seats metal to metal. Only that the rubber o-ring seals against the 3 sealing surfaces. Use grease on the o-ring and screw threads and tighten until things snug up with no leaks visible.

Blue Moon · Veteran Member

Just pulled my end caps today and have the tube stack in vinegar overnight, so reassembly should be tomorrow. In addition to some grease on the o-rings, which makes perfect sense, it appeared that there was some hardened sealant used on the cap screw threads on both ends. I'm carefully scraping the residue away so that it doesn't interfere in sealing the reassembly. But, what is the recommendation for any sealant to be used on the six cap screws securing the end caps. Is Tef-Gel, to avoid corrosion adherence, the right answer? Or is some one of the Permatex or other thread sealant products the way to go, or is something like Loctite Blue required?

Want to get the right and avoid any post-reassembly leaks!

-- Edited by Blue Moon on Saturday 16th of May 2020 08:10:37 PM

-- Edited by Blue Moon on Sunday 17th of May 2020 10:31:38 AM

Stanley · Guru

Tef-Gel should be perfect for this job.