Api Rp 1110.pdf May 2026

If you work in pipeline integrity, you’ve likely seen the file name: API_RP_1110.pdf . It usually sits in a folder alongside dozens of other standards—API 1160, ASME B31.8, DOT 192.

But in the era of high-frequency pressure cycling (thanks to renewable energy intermittency and batch switching), the 30-year-old assumptions in RP 1110 are being stress-tested like never before. Api Rp 1110.pdf

RP 1110 forces you to use the "devil's thickness"—the lowest possible thickness the mill was allowed to ship. This is why a pipeline that should test to 1,200 psi often tests to 1,140 psi. That 60 psi isn't a rounding error; it's the difference between elastic and plastic deformation. Most operators use RP 1110 for the acceptance criteria (e.g., "No drop in pressure for 1 hour"). But the coolest part is the section on cyclic pressure testing . If you work in pipeline integrity, you’ve likely