1 Scope
1.1 This recommended practice describes procedures which may be used to “prove-up” the depth or size of imper- fections. Included in this practice are the recommended pro- cedures for ultrasonic prove-up inspection of new pipe using the Amplitude Comparison Technique and the Amplitude- Distance Differential Technique for evaluation of
1) surface breaking imperfections in the body of pipe and
2) surface breaking and subsurface imperfections in the weld area of electric resistance, electric induction or laser welded pipe and
3) surface breaking and subsurface imperfections in the weld area of arc welded pipe. For the purpose of this document, pipe is defined as including casing, plain-end casing liners, tubing, plain-end drill pipe, line pipe, coiled line pipe, pup joints, coupling stock, and connector material.
1.2 Prove-up inspection is a method to evaluate the radial depth of imperfections detected by automated inspection equipment or other nondestructive testing (NDT) tech- nique(s) to determine acceptance criteria compliance with the appropriate API specification.
1.3 The recommended prove-up practices established within this document are intended as a guide, and nothing in this guide should be interpreted to prohibit the agency or owner from supplementing the guide with other techniques or extending existing techniques.
1.4 This RP covers evaluation, a description of inspection methods, calibration and standardization procedures, and inspection personnel requirements for prove-up.
1.5 Appendix A of this document is provided as an over- view to inform the user of the basis for the techniques outlined in this RP.
1.6 Appendix B of this document provides a procedure for determining if imperfections are surface breaking and a formula for calculating the sound path distance for a circumfer- ential or axial scan of a curved surface and a sample look-up table.
1.7 Appendix C of this document is provided as an over- view to inform the user of the specifics for the evaluation of welds with filler metal.
1.8 Appendix D of this document provides a procedure for sizing planar non-surface breaking imperfections from the pipe’s outside surface.
