Ethylene plant I used to contract for had a 80 to 600 Fahrenheit swing during startup. We caught an adhesive seal weeping on a steam line just before full pressure. Swapped to a spiral-wound gasket and never had a callback. For critical high-temp stuff, the extra install time is a cheap insurance policy.
Switched to mechanical seals after a similar scare last year. They handle the heat cycles way better, even if the install takes longer. No more pucker factor during rapid temp drops lol.