Replacement for heater elbow on 2F ... size and thread

[MAR FJ40]

Coolant pressure is like 15 psi normally so it doesn't a lot of force to contain it like 170 psi compression. Stack of washers, a section of metal tubing/pipe to make the spacer. Many of ways to skin a cat - none approved by cats

Not a cat fan except for barn cats. Barn cats are cool. I like the washer idea better than me hacking the fitting shorter as long as I can get a good seal.

 

[charliemeyer007]

Getting a seal and keeping the seal over time is the issue INHO. Thermal cycles and vibrations can loosen things over time. Tapered pipe threads are designed to tighten internally, regular thread needs to tighten externally on like the bolt head, fitting shoulder or the bottom of the hole....

Not a house cat person either, but I do like Cougars - both kinds!

Merry Christmas!