Leading global certifications set the benchmark. ISO 4427 series covers PE fittings for buried or above-ground water applications with maximum allowable operating pressure up to 25 bar. ASTM standards establish requirements for billets and prescribe minimum quality control measures for manufacturers.Don’t compromise on quality or rely solely on low cost. Demand verifiable certifications. Keep manuals and material test reports on record. .https://ifanplus.com/knowledge/can-you-screw-into-hdpe/