ASME Temper Bead Welding of P1 Material for a Deaerator Repair

[RobsVette]

Greetings,

Currently I am looking at writing a weld procedure for temper bead welding. We are looking at potentially performing a repair on a deaerator and are considering the use of temper bead procedures vs post weld heat treatment to prevent stress hardening.

If you guys have any good resources for where I could find information regarding temper-bead welding, I would greatly appreciate it. Any information on how the weld is exactly done and metallurgical stress relief would be greatly appreciated.

The vessel we would be working on is a deaerator, so it would be a relatively thin wall (probably 3/8") and the material is carbon steel.

If I can provide any other information that is needed please let me know, or if you need other questions or comments also please let me know.

Thanks
Rob

 

[metengr]

RobsVette;
I would suggest you use the National Board Inspection Code (NB-23) because this weld repair would fall under this code. The temper bead is described in one of the Alternative Welding methods. The temper bead WPS will require qualification in accordance with ASME B&PV Code, Section IX.

If you want additional information here is another source regarding temper bead;

http://www.wtia.com.au/pdf/TGN-PE-02 Temper Bead Welding.pdf

Why would you consider temper bead when PWHT is not required for this vessel if it is manufactured from carbon steel. I would consider use of elevated preheat and weld repair as required.

 

[RobsVette]

metengr,

The deaerator in question does require stress relieving even though it is only 3/8" thick. From my experience, most deaerators do require stress relieving due to being subject to extreme thermal shocking from cold make up water entering a hot vessel. They may also have a requirement for double welding (inside and outside)for the exact same reason.

thank you for the links and information.

 

[metengr]

RobsVette:
The DA vessel being carbon steel is exempt from PWHT because of the material thickness, if built to ASME Boiler and Pressure Vessel Code, Section VIII, Div 1. Now, you can always specify PWHT above and beyond code requirements. I have seen this done for DA vessels to reduce susceptibility to stress corrosion cracking or corrosion fatigue for weldments located at or below the waterline in service.