Localized PWHT for pressure vessel
Localized PWHT for pressure vessel
(OP)
Greetings
We're doing repair work for pressure vessel as per EN 13445.
Repair work means "cutting deep dent-damaged area and re-welding with new plate as square size".
After re-welding, localized PWHT as per client's requirement has been planned. But, we're worried about deformation during and/or PWHT. Because, this vessel will be subject to the localized PWHT only for damaged area (3.4m X 5.8m) as per EN standard not entire circumference.
Vessel specification is as below.
- Design code : EN 13445
- Material : P355 NL1
- Thickness : 33mm(existing) / 35mm(new plate to be welded)
- Inside diameter : 7,210mm
- PWHT Temp. : 550-600
Our concern is deformation that may be happened during and/or after PWHT.
To avoid any problem, we've searched for proper manner such as reinforcement inside, but nobody makes it sure.
What is the best method to avoid deformation? And, if using reinforcement, is it available?
We're doing repair work for pressure vessel as per EN 13445.
Repair work means "cutting deep dent-damaged area and re-welding with new plate as square size".
After re-welding, localized PWHT as per client's requirement has been planned. But, we're worried about deformation during and/or PWHT. Because, this vessel will be subject to the localized PWHT only for damaged area (3.4m X 5.8m) as per EN standard not entire circumference.
Vessel specification is as below.
- Design code : EN 13445
- Material : P355 NL1
- Thickness : 33mm(existing) / 35mm(new plate to be welded)
- Inside diameter : 7,210mm
- PWHT Temp. : 550-600
Our concern is deformation that may be happened during and/or after PWHT.
To avoid any problem, we've searched for proper manner such as reinforcement inside, but nobody makes it sure.
What is the best method to avoid deformation? And, if using reinforcement, is it available?





RE: Localized PWHT for pressure vessel
RE: Localized PWHT for pressure vessel
RE: Localized PWHT for pressure vessel
Distortion can be minimized with proper application of PWHT.
RE: Localized PWHT for pressure vessel
http://www.ultragen.com/doc/tech-articles/en/Artic...
RE: Localized PWHT for pressure vessel
Length (From T.L to T.L) is 52,800mm.
There are two repair locations. One is located at the bottom of vessel and, another is located on the side of vessel. Both locations are so far on the vessel (Approximately, 30,0000mm).
Dimension of both repair areas is almost same.
We've been doing stress analysis to measure the distortion during PWHT, but it's not easy job. Distortion on few areas has been predicted after preliminary analysis. To minimize distortion, proper method of PWHT is required.