1.1 This specification covers polyethylene (PE) pipe made in thermoplastic pipe dimension ratios based on outside diameter and pressure rated for water (see Appendix X1). Included are criteria for classifying PE plastic pipe materials and P This specification covers polyethylene (PE) pipes made in thermoplastic pipe dimension ratios based on outside diameter, and pressure rated for water. All pipes produced under this specification may be used for the transport of water, industrial proces