This standard specifies the classification, requirements, test methods, inspection rules, marking and packaging of hydraulic lap welding method flanges (hereinafter referred to as method flanges). This standard applies to the design, manufacture and acceptance of square flanges of hydraulic oil steel pipes with nominal pressure PN ≤ 250.
CB/T 4228-2013 Referenced Document
GB/T 1184-1996 Geometrical tolerancing--Geometrical tolerance for features without individual tolerance indications
GB/T 1800.4-1999 Limits and fits Tables of standard tolerance grades and limit deviations for holes and shafts
GB/T 1804-2000 General tolerances Tolerances for linear and angular dimensions without individual tolerance indications