Working pressures indicated are based on atmospheric temperatures. Refer to specification for additional details on pressure ratings based on other temperatures, and materials as well as gasket and bolt requirements.
When choosing a flange for your application, it is helpful to know that the most commonly available flanges are ASME/ANSI B16.5 and AWWA C207 series flanges. This generally means that these flange selections are the most economical choices.
100% US Manufactured Flanges Available on Request.
Note this is a limited summary based on most commonly used AWWA flange types. Please contact CAB, or consult the latest AWWA C207 or C228 specification for more detailed information.
AWWA flanges may be produced from plate, bar or forged materials. Steel must meet following requirements:
| Minimum Tensile Strength | 50,000 psi / 345 Mpa |
|---|---|
| Minimum Yield Strength | 32,000 psi / 221 Mpa |
| Elongation based on 2" gage length min | 18% |
| Elongation based on 8" gage length min | 14% |
| Carbon maximum | .29 percent |
| Phosphorus maximum | .04 percent |
| Sulfur maximum | .05 percent |
Bolt lengths calculation:
Sum of flange maximum thickness + gasket thickness + washer thickness + depth of nut + 1/4 inch minimum. If using studs, add depth of second nut and washer plus an additional 1/8".
Rubber gaskets with hardness Shore A 70-85 with gasket seating stress of 200 psi conforming to ASTM D1330 Grade 1 or Compressed Fiber (CFG) or PTFE gaskets may be used and must be suitable for minimum of 4800 psi seating stress.
Ring gasket diameters (if not using full face gaskets extending to OD) shall be:
| Outside Diameter (OD) | +- 1/8" (3.2mm) |
|---|---|
| Inside Diameter (ID) | + 1/16" (1.6mm) -0 |
| Thickness 18" nominal and smaller | +1/8 (3.2mm) -0 |
| Thickness 20" nominal and larger | +3/16" (4.8mm) -0 |
| Bolt Circle Diameter (BC) | +- 1/16" (1.6mm) |
| Bolt Hole Spacing (aka Chord) | +- 1/32" (.79mm) |
Flanges are typically supplied with spiral serrated finish with 24-55 grooves per inch. Concentric serrated finish may be available by special order though it is rarely used. A cutting tool of .06" radius or less should be used, yielding 125-500 RMS (3.2-12.7 RA) roughness.
AWWA Test Pressures are 1.5 times flange pressure ratings.
Note this is a limited summary based on most commonly used flange types. Please contact CAB, or consult the latest ASME/ANSI B16.5 specification for more detailed information.
Most common carbon steel materials used on B16.5 flanges are A105, A350 LF2, A 515-70 (Blinds Only), A 516-70 (Blinds Only).
B16.5 specification allows for several types of gaskets depending on operating environment. Consult specification for details.
ASTM A193 B7 bolts are commonly used as the minimum strength requirement on bolting for ASME/ANSI B16.5 flanges. The specification allows for other options based on flange pressure class.
Test pressures on B16.5 flanges are 1.5 times of pressure rating.
CAB supplied B16.5 flanges will be marked B16.5, pressure class, material grade, heat # and mfr.
(Partial listing of common slip on flange tolerances; more details in ASME/ANSI B16.5 specification)
| Outside Diameter | - |
|---|---|
| Inside Diameter 10" nominal and smaller | +.03" -0 |
| Inside Diameter 12" nominal and larger | +.06" -0 |
| Thickness 18" nominal and smaller | +.12" -0 |
| Thickness 20" nominal and larger | +.19" -0 |
| Bolt Circle | - |
| Bolt Hole Spacing | - |
| Bolt Circle Concentricity - 2.5" and smaller | .03" |
| Bolt Circle Concentricity - 3" and larger | .06" |
B16.5 flanges are typically supplied with a raised face, which is added to the minimum flange thickness (thickness through bolt hole). For Class 150 and 300 .06" is added. For Class 400, 600, 900, 1500 and 2500, .25" raised face is added.
Flat faced flanges are available. Flange faces are typically supplied with a spiral serrated finish of 44-55 grooves per inch with RMS of 125-250 (3.2 to 6.3 RA) finish.
Note this is a limited summary based on most commonly used flange types. Please contact CAB, or consult the latest ASME B16.47 specification for more detailed information.
Most common carbon steel materials used on B16.47 flanges are A105, A350 LF2, A 515-70 (Blinds Only), A 516-70 (Blinds Only).
Nonmetallic gaskets should conform to ASME B16.21; Metallic gaskets should conform to ASME B16.20.
ASTM A193 B7 bolts are commonly used as the minimum strength requirement on bolting for ASME B16.47 flanges. The specific allows for other options based on flange pressure class.
Flanges are not required to be pressure tested.
CAB supplied B16.47 flanges will be marked B16.47, pressure class, material grade, heat # and mfr.
(Partial listing of common slip on flange tolerances; more details in ASME B16.47 specification)
| Inside Diameter 10" nominal and smaller | +.03" -0 |
|---|---|
| Inside Diameter 12" nominal and larger | +.06" -0 |
| Thickness of Flange through bolt hole 1" or less | +.12" -0 |
| Thickness of Flange through bolt hole >1" to 2" | +.19" -0 |
| Thickness of Flange through bolt hole >2" to 3" | +.31" -0 |
| Thickness of Flange through bolt hole >3" | +.38" -0 |
| Bolt Circle | .06" |
| Bolt Hole Spacing | .03" |
| Bolt Circle Concentricity | .06" |
B16.47 flanges are typically supplied with a raised face, which is added to the minimum flange thickness (thickness through bolt hole). For Class 75, 150 and 300 .06" is added. For Class 400, 600 and 900, .25" raised face is added. Flat faced flanges are available on request.
Flange faces are typically supplied with a spiral serrated finish of 44-55 grooves per inch with RMS of 125-250 (3.2 to 6.3 RA) finish.
ASME B 16.47 Series A was formerly known as MSS SP 44 specification. Series B was formerly known as API 605 specification. Now both have been combined and included in ASME B16.47 specification.
Class 125 lightweight flanges are not governed by a flange specification. They are a hub designed slip on type flange with drilling that matches 150# or 125# drill pattern. The flanges do not have an official pressure rating, however, early AWWA specifications had a Table 2, Class D hub type slip on that is same dimensions and pressure rating for that flange as 150psi.
Ductile Iron backup flanges do not have a flange specification. They are considered "unrated" flanges for use on non-pressure type applications. Drilling pattern matches 150# or 125# drilling.
Pressure vessel flanges are designed per ASME Section VIII and are designed for pressure vessel use. They are only rarely used and are generally built to order.
Tubeturns 150# and 300# slip on flanges were originally designed by Tubeturns and appeared in their flange catalog for many years. Drill patterns were designed to match up to common valve drilling patterns 150# and 125# and 300# and 250# patterns.