The Flat Face flange has a gasket surface in the same plane as the bolting circle face. Applications using flat face flanges are frequently those in which the mating flange or flanged fitting is made from a casting.
Flat face flanges are never to be bolted to a raised face flange. ASME B31.1 says that when connecting flat face cast iron flanges to carbon steel flanges, the raised face on the carbon steel flange must be removed, and that a full face gasket is required. This is to keep the thin, bittle cast iron flange from being sprung into the gap caused by the raised face of the carbon steel flange.
This flange helps in easy access to a line once it has been sealed. The blind flange is sometimes custom made or machined to accept a nominal sized pipe to which reduction is being made. This reduction can be a threaded reduction or welded reduction.
Material:
- Cabon steel: A105, A350 LF2
- Stainless steel: A182 F304/F304L/F316/F316L/F321
- Alloy steel: F11, F12
- Packing: plywood case and plywood pallet
Specifications:
- ASME/ANSI B16.5 Class 150 BL
- ASME/ANSI B16.5 Class 300 BL
- ASME/ANSI B16.5 Class 600 BL
- ASME/ANSI B16.5 Class 900 BL
- ASME/ANSI B16.5 Class 1500 BL
- ASME/ANSI B16.5 Class 2500 BL
- ASME B16.47 Series A/MSS SP-44 Class 150 BL
- ASME B16.47 Series A/MSS SP-44 Class 300 BL
- ASME B16.47 Series A/MSS SP-44 Class 600 BL
- ASME B16.47 Series A/MSS SP-44 Class 900 BL
- ASME B16.47 Series B/API 605 Class 75 BL
- ASME B16.47 Series B/API 605 Class 150 BL
- ASME B16.47 Series B/API 605 Class 300 BL
- ASME B16.47 Series B/API 605 Class 600 BL
- ASME B16.47 Series B/API 605 Class 900 BL
- DIN 2527 PN10
- DIN 2527 PN16
