1. The forging material should be fabricated, inspected and accepted according to JB4726-2000.
2. The plumbness tolerance of tubesheet sealing face to center axis shall be within 0.5mm.
3. The distance for more than 96% of tube hole-bridge of the tubesheet must be exceed 3.36mm,not less than 2.38mm for 4% of tube hole-bridge.
4. The tolerance on bolt circle diameter and bolt hole spacing shall be ±0.6mm,the tolereance on random bolt hole spacing shall be ± 1.0mm.
5. The tolerance of the dimension for surface machined shall be in accordance with GB/T1804-2000 , grade m, other with grade c. |