Common specifications and models of PE water supply pipes are typically distinguished by their outer diameter and wall thickness.

Common outer diameters include 20mm, 25mm, 32mm, 40mm, 50mm, 63mm, 75mm, 90mm, 110mm, 125mm, 140mm, 160mm, 180mm, 200mm, 225mm, 250mm, 280mm, 315mm, 355mm, 400mm, 450mm, 500mm, 560mm, and 630mm.

Wall thickness varies depending on the pressure grade and outer diameter. Generally, common pressure grades include SDR11 (standard dimension ratio) and SDR17.6.

Note that the specific model selection should be determined based on actual engineering requirements, usage environment, and pressure requirements, among other factors.