Flat face flange

TYPE 5 SLIP-ON FLANGE, FLAT FACE, FULL GASKET... 

Figure 2-15. Dimensional data and forces for a slip-on flange, flat face, full gasket.

Casing Connections. Connections shall he A.N.S.I. flat-faced flanges. [Cast iron (125) (250) psig rated] [Duron metal, steel, alloy steel (150) (300) psig rated]... 

Figures 10-133 and 10-134 illustrate the wide variety of types and facings available. Though flanged joints consume a large volume of metal, precise machining is required only on the facing. Flanged joints do not impose severe diametral tolerances on the pipe. Careful alignment prior to assembly of flat-face and raised-face flanges is not required, and the necessary wrenches are far smaller than those for screwed assembly for the same size of pipe.

For flanges of nonstandard dimensions or for sizes beyond the scope of the approved standards, design shall be in accordance with the requirements of the ASME Boiler and Pressure Vessel Code, Sec. T11, except that requirements for fabrication, assembly, inspection testing, and the pressure and temperature hmits for materials of the Piping Code are to prevail. Countermoment flanges of flat face or otherwise providing a reaction outside the bolt circle are permitted if... 

Flat face flange. Appendix Y. Fig. UA-111Q Welded connection. UW IS. UW 16. Fig. UW 15.1 Opening. UG 35to UG 42, UA 7. UA 280 Multiple openings. UG-42 Non pressure parts. UG-6, UG-22. UG-SS. UG-82 Hemispherical head. Pressures. 

Bolting a raised-face flange to a flat-faced, cast-iron flange can create bending moments in the less ductile cast-iron flange, which could cause it to crack. 

Cast iron flanges shall be flat face and shall, as a minimum, conform to the dimensional requirements of ISO 7005-2 (ANSI/ASME B16.1). 

Flat face flanges with full raised face thickness are acceptable on casings of all materials. Flanges in all materials that are thicker or have a larger outside diameter than that required by ISO (ANSI) are acceptable. 

A170 Other conn facing OTHER FACE c 1 A flat face B raised flange C ring type joint threaded Z other... 

Cast iron flanges shall be flat faced and, except as noted in 5.4.2.4, conform to the dimensional requirements of ISO 7005-2 and the flange finish requirements of ASME B16.1 or ASME B16.42. PN 20 (Class 125) flanges shall have a minimum thickness equal to that of PN 40 (Class 250) flanges for sizes DN 200 (8 NPS) and smaller. 

The lumped thermal mass equation also describes the heating-up process of flat face or clamp flanges, where the failure mode is, however, the loss of tightness and consequent secondary leak and fire. It should be noted that when the limped thermal mass heat transfer model was used for the calculation of time-to-failure of flanges engulfed by fire, the results agreed well with the full scale tests in Ref 4. 

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