Those century-old steam systems in old factories, are they really that hard to deal with? I've seen plenty of seized bolts, but most times they're not as bad as people say. Just get a can of penetrating oil and let it sit for a day or two. A little heat from a torch can help, but go slow so you don't damage the surrounding metal. The real issue is when people get impatient and crank on them with a cheater bar. That's how you break stuff. Take your time, and it usually comes loose without a fight.