Rationale

A53 pipe in small sizes of ERW pipe have exhibited very high Y/T ratios that have affects on cold bending and threading of these pipes. A summary of heats shows that at least 50% of all present heats in sizes from NPS2-4 have Y/T ratios exceeding 90% and yields in excess of 55,000 psi. To allow users who have concerns about these unusual properties and the affects they have on bending, a supplementary requirement will be proposed to allow limiting the maximum yield and perhaps the Y/T ration.