... ISO and Non standard,4. Size:1/2"-48"5. Type:Slip-on flanges, Blind flanges, Lap joint flanges, Welding ... .8. Used for : petroleum,chemical,power,gas,water,linepipe, heat exchanger,shipbuilding,construction,etc.9. Tolerance:not less than +_8% of ... thickness.10.Production process : raw material--cutting--heating--forging--heat treatment--maching--inspection.-washing-ex-working.11. Mill ceitificate : ...