Tube rolling after PWHT or before PWHT
Tube rolling after PWHT or before PWHT
(OP)
Hi Guys,
Is that possible to expand (Rolling) tube to tubesheet after PWHT? The bundle is in sour services and tubesheet have both tube to tubesheet weld and grove expands area. The hardness of tube expanded area (As measured in a sample) is less than 178 Brinle after rolling.
Is that practical to perform rolling before PWHT? This will not lead to weld cracking during PWHT?
Is that possible to expand (Rolling) tube to tubesheet after PWHT? The bundle is in sour services and tubesheet have both tube to tubesheet weld and grove expands area. The hardness of tube expanded area (As measured in a sample) is less than 178 Brinle after rolling.
Is that practical to perform rolling before PWHT? This will not lead to weld cracking during PWHT?





RE: Tube rolling after PWHT or before PWHT
Go back and check to make sure that the tube-to-tubesheet weld joints are only seal welds and not strength (partial penetration) groove welds. If you need to roll the tubes, this would have to be performed after PWHT to derive any benefit from rolling.
RE: Tube rolling after PWHT or before PWHT
gr2vessels
RE: Tube rolling after PWHT or before PWHT
The order is improtant.
I have seen a lot of cases us rough tubesheet holes instead of actuall grooves. It works just as well.
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Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Tube rolling after PWHT or before PWHT
RE: Tube rolling after PWHT or before PWHT
If you are PWHT then you will roll the tubes afterwards. Tubes that are strength welded must be expanded into the holes. Even though you don't need the strength or sealing you can't risk haveing the tubes loose. I have seen many tubes fatigue at the back face of the tubesheet because they were loose. Not only does this make the first span longer than designed it also allows the tube to impact the edges of the holes.
Stan has been doing this stuff for a long time, read his papers.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Tube rolling after PWHT or before PWHT
rmw
RE: Tube rolling after PWHT or before PWHT
Please correct the gap length behind the weld root in my post. I shoulden't post information when I am half asleep. The gap should be 12.5 mm or slightly more, not 50 mm. Mea Culpa Surprised that no on picked me up short.
Stan