Hello all, which part of ASME is

[parsomash1977]

Hello all,

which part of ASME is talking about longitudinal crack on a boiler tube. We got a 4-5 inches crack on down comers side and I need to follow ASME code to repair that. Your advice is highly appreciated.

Thanks

 

[metengr]

ASME Code is not a repair code, it is a construction code so no specific guidance is provided for in-service repairs.

For in-service repairs of boilers you need to folow the National Board Inspection Code (NB-23 publication).

If this is a waterwall tube and yuo have an axial crack, I would replace the tube section with a dutchman (new tube) butt welded on each end to the existing tube away from the damage.

Use a qualified welding procedure based on material, and perform a post repair non-destructive test (x-ray) or other surface NDT.

 

[metengr]

Also, removing the failed tube section for a dutchman repair will allow you to determine what caused the axial crack. I would bet it is either corrosion fatigue crack propagation or short term overheat (axial thin-lipped split).

 

[parsomash1977]

thanks metengr

 

[chicopee]

Can you tell us more about this watertube boiler such as manufacturer, type, year build, MAWP, heating tube and superheater surface areas. .

 

[parsomash1977]

It's a 200 klb/hr A type CLEAVER BROOKS boiler with dry saturated steam of 450 psi. almost 20 years old.