With a fillet welded patch installed, the maximum SMYS allowed for the pipe is

With a fillet welded patch installed, the maximum SMYS allowed for the pipe is

• A. 50,000 psi
• B. 30,000 psi
• C. 60,000 psi
• D. 40,000 psi

Answer: (D)

When a fillet welded patch is added, the pipe’s allowable stress is reduced to account for the added discontinuity and the weld’s limited capacity. The rule used here is to limit the maximum SMYS to about two-thirds of the pipe’s specified minimum yield strength. This provides a safety margin because the patch and its welds don’t carry load as reliably as the intact base metal. So, if the pipe’s SMYS is 60,000 psi, the highest allowable SMYS with the patch in place is 40,000 psi (0.66 × 60,000).

When a fillet welded patch is added, the pipe’s allowable stress is reduced to account for the added discontinuity and the weld’s limited capacity. The rule used here is to limit the maximum SMYS to about two-thirds of the pipe’s specified minimum yield strength. This provides a safety margin because the patch and its welds don’t carry load as reliably as the intact base metal.

So, if the pipe’s SMYS is 60,000 psi, the highest allowable SMYS with the patch in place is 40,000 psi (0.66 × 60,000).