Following this comment, it was decided that a different regrouping of the product control numbers that would allow for a similar level of comparability can be applied — namely with regard to pipe diameter and wall thickness.
Selle märkuse alusel leiti, et võib kohaldada teistsugust toote kontrollnumbrite rühmitamist, mis tagab samasuguse võrreldavuse – nimelt toru diameetrist ja seina paksusest tulenevat.