For welded pipe, the normal under-tolerance thickness is which value?

For welded pipe, the normal under-tolerance thickness is which value?

• A. .010 or 10 mils
• B. .020
• C. .005
• D. .015

Answer: (A)

Under-tolerance is the fixed amount by which a pipe wall may be thinner than its nominal design thickness and still pass inspection. For welded pipe, the standard under-tolerance is 0.010 inch (10 mils). This means you can subtract 0.010 from the nominal thickness to get the minimum acceptable thickness before it’s considered out of tolerance. For example, with a nominal thickness of 0.250 inches, the minimum acceptable thickness is 0.240 inches. Values thinner than that would require corrective action. The other options do not represent the standard under-tolerance used for welded pipe.

Under-tolerance is the fixed amount by which a pipe wall may be thinner than its nominal design thickness and still pass inspection. For welded pipe, the standard under-tolerance is 0.010 inch (10 mils). This means you can subtract 0.010 from the nominal thickness to get the minimum acceptable thickness before it’s considered out of tolerance. For example, with a nominal thickness of 0.250 inches, the minimum acceptable thickness is 0.240 inches. Values thinner than that would require corrective action. The other options do not represent the standard under-tolerance used for welded pipe.