49 CFR §192.59

1. (a)New plastic pipe is qualified for use under this part if:
   1. (1)It is manufactured in accordance with a listed specification;
   2. (2)It is resistant to chemicals with which contact may be anticipated; and
   3. (3)It is free of visible defects.
2. (b)Used plastic pipe is qualified for use under this part if:
   1. (1)It was manufactured in accordance with a listed specification;
   2. (2)It is resistant to chemicals with which contact may be anticipated;
   3. (3)It has been used only in gas service;
   4. (4)Its dimensions are still within the tolerances of the specification to which it was manufactured; and
   5. (5)It is free of visible defects.
3. (c)For the purpose of paragraphs (a)(1) and (b)(1) of this section, where pipe of a diameter included in a listed specification is impractical to use, pipe of a diameter between the sizes included in a listed specification may be used if it:
   1. (1)Meets the strength and design criteria required of pipe included in that listed specification; and
   2. (2)Is manufactured from plastic compounds which meet the criteria for material required of pipe included in that listed specification.
4. (d)Rework and/or regrind material is not allowed in plastic pipe produced after March 6, 2015 used under this part.