Picked up a trick from an old timer for freeing stuck exhaust nuts on turbines

I had a PT6 that wouldn't budge after 3 hours with a breaker bar so I tried heating the flange with a propane torch just enough to expand it and let it cool twice, then the nut came off by hand, has anyone else used heat cycling like that on hot section fasteners?

3 comments

3 Comments

the_julia26d ago

Read somewhere that some guys in the hangar do that with compressor bleed valves too. Guess the old timers knew what they were doing with the whole heat-soak thing.

abby_king2225d ago

@the_julia you're right about the bleed valves, I've actually had to deal with that exact thing on a hot section swap a few years back. Let that compressor cool for a good 20 minutes before cracking the bleed lines, and the seals came out PERFECT. Had another guy rush it on a different bird, no heat soak, and we ended up chasing leaks for a week. Those old timers figured out that thermal shock kills the softer seal material way faster than just waiting around does. Plus it gives you time to actually check over your paperwork instead of rushing into the next step blind.

linda_clark26d ago

So did you ever actually see the old timers do it, or is it one of those hangar stories that gets passed down like folklore? I've heard a few old heads swear by it, but then I've also seen newer guys claim it's just wasted time. The whole heat soak debate seems to split the room every time it comes up. Seems like nobody can agree on whether it actually saves wear on the seals or if it's just an old habit that stuck around. What's your gut on it after hearing both sides now?