Learned a trick from an old boilermaker in Texas last spring

I was working a shutdown at a refinery in Port Arthur and this older guy named Roy showed me how to set a tube with a simple string line instead of a level. He said levels can lie on hot pipe but a string never does. I tried it on a row of superheater tubes and it was dead nuts accurate. Any of you guys use string over a level in tight spots?

2 comments

2 Comments

john_johnson7513d agoMost Upvoted

Wouldn't a wet string sag more than a dry one on hot pipe?

paulperez13d ago

Hang on, that's not quite how it works. The string itself isn't gonna sag more from being wet. The real problem is the moisture messes with the tension. When the pipe gets hot, the water trapped in the string can turn to steam, which makes the fibers expand and get loose. That's where the sag comes from, not just the weight of the water. It's the heat and steam combo that changes the string's shape. So yeah, you're close, but it's more about the boiling reaction than extra weight.