scope:

This method describes the procedure to be used in determining the quality of the seam or helical, continuously welded seam, corrugated steel pipe. The procedure to be used involves distorting a short length of welded seam by using a 25-mm diameter, hemispherical punch and a 38-mm inside diameter contoured die. The resulting distorted weld area will hereafter be called the "cup."

At the option of the engineer, or in the event of a disagreement between the engineer and fabricator, the referee test described in Section 4 will be performed.

The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of R 18 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with R 18 alone does not completely assure reliable results. Reliable results depend on many factors; following the suggestions of R 18 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.