5. Slip-on flanges may be used in Class I and II fluid services for ANSI Classes 300 and below, at design temperatures above 30oF (-1oC). Weld neck flanges shall be used in Class II or III fluid services, except slip-on flanges may be used for injection nozzles and similar cases where a smaller line must be installed inside a larger flanged nozzle. Slip-on flanges shall be welded inside and outside. Refer to Figure 328.5.2B of ASME B31.3. The weld shall be applied so that the flange face shall be free of weld spatter and does not require refacing.
6. Acceptance criteria and evaluation of flange facing finish shall be in accordance with ASME B16.5 and ASME B16.47.
7. Where lap joint stub ends are used, flange stops (same material as pipe) shall be furnished by fabricator.
D