... water hygiene standard 4.100m/coil in plastic film 5. black pipe uv protection pex pipe .uv protection pex pipe advantages1 ... passed the drinking water hygiene standards.The outer layer containing carbon black anti-ultraviolet radiation. The service life is 25 yr if ... ,hoop stress4.4Mpa,1000h,not cracking,no leakage UV Protection Black water pipe PEX