pvc fitting for water supply standard: JIS,ASTM, BS All Lipson Fittings( such as PVC reducing socket)are produced from High Precision ... Machines for Quality Consistency and Superior Product Finishing. Our pipes and fittings can be made, according and conforming to ... ISO 4422, ISO 3633, IEC 614, GY 3050) All Lipson PVC pipes and fittings are approved and certified by the National QualitySupervision ...