... ,Dia250mm. 1) American standard (ASTM Sch 40 & Sch 80, SDR 21, SDR 26, SDR41)2) British standard (BS 3505, BS ... 5255, 4515)3) Singaporean standard (SS 141, SS 272, SS ... 6741, JIS K 6743, JIS K 6739)6) National standard (GB 10002, GB 5836, GB 14823, GB 13664)7 ... ) International standard (ISO 4422, ISO 3633, IEC 614, GY 3050) ...