AWWA C207 and AWWA C228 are two different standards established by the American Water Works Association (AWWA), each applicable to different pipeline connection components. Below are their main differences:
Scope of Application
AWWA C207: Applicable to steel pipe flanges, covering sizes from 4 inches to 144 inches, and is suitable for water treatment plants, wastewater treatment plants, and similar applications.
| Standard | AWWA C207 | |||||||||
| Type | Steel Ring Flanges | Blind Flanges | Steel Hub Flanges | |||||||
| Size Range | 4”-144” | 4”-144” | 4”-144” | 4”-48” | 4”-72” | 4”-72” | 4”-72” | 4”-72” | 4”-96” | 4”-96” |
| Pressure Rating | Class B | Class D | Class E | Class F | Class B | Class D | Class E | Class F | Class D | Class E |
| Working Pressure | 86 psi | 175-150 psi | 275 psi | 300 psi | 86 psi | 175-150 psi | 275 psi | 300 psi | 175-150 psi | 275 psi |
AWWA C228: Applicable to stainless steel pipe flanges, with sizes ranging from 2 inches to 72 inches, primarily used in environments requiring corrosion resistance.
| Standard | AWWA C228 | |||||||||
| Type | Steel Ring Flanges | Blind Flanges | ||||||||
| Size Range | 2”-72” | 2”-72” | 2”-72” | 4”-48” | 4”-48” | 2”-72” | 2”-72” | 2”-72” | 2”-72” | 2”-72” |
| Pressure Rating | Class SA | Class SB | Class SD | Class SE | Class SF | Class SA | Class SB | Class SD | Class SE | Class SF |
| Working Pressure | 50 psi | 86 psi | 175-150 psi | 275 psi | 300 psi | 50 psi | 86 psi | 175-150 psi | 275 psi | 300 psi |
Pressure Ratings
AWWA C207: Provides multiple pressure ratings (e.g., Class B, D, E, F) to accommodate different working pressures.
AWWA C228: Pressure ratings are similar to C207, but due to the material differences, it is more suitable for corrosive environments.
Materials
AWWA C207: Primarily targets carbon steel or stainless steel flanges.
| Property | Requirement |
| Specified Minimum Tensile Strength | 50,000 psi (345 MPa) |
| Specified Minimum Yield Strength | 32,000 psi (221 MPa) |
| Elongation | – 2-in. (50-mm) gauge length (minimum): 18% |
| – 8-in. (200-mm) gauge length (minimum): 14% | |
| Carbon (Maximum) | 0.35% |
| Phosphorus (Maximum) | 0.04% |
| Sulfur (Maximum) | 0.05% |
AWWA C228: Specifically designed for stainless steel flanges, offering superior corrosion resistance.
| Section | Requirement |
| Flanges | Flanges shall be made from: |
| – Castings | |
| – Seamless forgings | |
| – Rolled and welded bar rings | |
| – Segmented and welded plates | |
| – Cut from plate as a single piece | |
| Note: The purchaser shall specify the materials to be used. | |
| Castings | Cast stainless-steel flanges shall meet the minimum requirements of ASTM A351. |
| Forgings | Forgings shall meet the minimum requirements of ASTM A182 certified stainless-steel material. |
| Plate/Bar | Stainless-steel plate or bar shall meet the minimum requirements of ASTM A240 or ASTM A276. |
| Minimum Strength | Specified Minimum Yield Strength: 30,000 psi (205 MPa). |
| Standard | Material Designations |
| ASTM A240 | Types: 304N, 304H, 316N, 316H, 317L, 317LMN, 321 |
| Alloys: 2205 (S32205), 2202 (S32202), 2101 (S32101), 2003 (S32001), 2304 (S32304) | |
| ASTM A182 | Alloys: 2202 (S32202), 2205 (S32205) |
| Types: 304N (S30451), 304H (S30409), 316N (S31651), 316H (S30609), 317L (S31703), 317LMN (S31726), 321 (S32100) | |
| Dual-Certified | ASTM A240 Types: 304/304L, 316/316L |
Application Environments
AWWA C207: Widely used in general water supply systems.
AWWA C228: Suitable for highly corrosive environments, such as seawater desalination or chemical processing plants.
Standard Content
AWWA C207: Covers flange dimensions, thickness, bolt hole arrangements, and more.
AWWA C228: In addition to dimensions and pressure ratings, it specifically addresses the corrosion resistance properties of stainless steel materials.
Summary
AWWA C207: Suitable for steel flanges in general water supply systems.
AWWA C228: Suitable for stainless steel flanges in corrosive environments.
For more information about AWWA C207/C288, please contact SSM. We provide product and technical service support.
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