We produce steel and stainless steel AWWA flanges for waterworks service to comply with American Water Works Association (AWWA) C207 and C228 specifications.
The American Water Works Association (AWWA) was founded in 1881 to establish and unify standards across the water industry. With members ranging from utility operators and engineers to manufacturers and public health professionals, AWWA plays an important role in ensuring safe, efficient, and reliable water systems throughout North America and beyond.
AWWA is best known for its rigorous standards program, which began in 1908. These standards guide the design, manufacturing, and application of products used in water systems—especially piping components like AWWA flanges.
AWWA flanges, defined under the AWWA C207 and C228 standards, are commonly used in low-pressure waterworks applications. Manufactured from carbon steel or ductile iron, they offer strength, durability, and corrosion resistance what makes them ideal for municipal and industrial pipelines, treatment plants, and pump stations.
AWWA standards set clear guidelines for flange dimensions, materials, and production and ensure reliable connections and leak-free performance. With over 150 active standards, AWWA also supports a wide range of water system components, processes, and equipment, including:
A Slip On Flange is a type of pipe flange that is slipped over the end of a pipe and welded in place.
A Blind Flange is a detachable sealing device used to block off a pipeline or to create a stop.
Hub Ring Flanges are manufactured to AWWA C207 and ANSI #150 bolt pattern specifications.
An AWWA flange is a type of pipe flange designed for waterworks service. It follows standards developed by the American Water Works Association and is typically used in low-pressure systems like municipal pipelines, treatment plants, and irrigation systems.
The American Water Works Association (AWWA) provides two main standards for flanges for water-work applications:
AWWA C207 – carbon steel flanges
AWWA C228 – stainless steel flanges
These standards also define dimensions, drilling patterns, pressure ratings, and material properties.
AWWA C207 covers carbon steel flanges for low-pressure water service, while AWWA C228 covers stainless steel flanges for the same applications. Both define dimensions, pressure classes, and material requirements.
Pressure ratings vary by class:
These ratings apply to water service and depend on flange size and material.
AWWA flanges are primarily used in waterworks applications and cover larger size ranges (up to 144″ in diameter) but lower pressure ratings.
ANSI/ASME flanges are designed for industrial systems with higher pressure requirements and cover smaller diameters (up to 24″ in diameter).
ASME Flanges cover the remaining sizes from 26”-60” in diameter.
Pressure classes are defined in AWWA as class A, B, D, E, and F, (or SA, SB, SD, SE, SF for stainless steel versions) whereas in ANSI/ASME pressure classes are defined as 150, 300, 400, 600, 900, 1500, and 2500.
Capabilities:
• Custom Bolt Holes, Overbore, Counterbore, Tapped, Welds, O-ring Grooves, Threads, Special Serrations, Bevels, Chamfers
Thread Style:
• Metric Parallel, Metric Tapered, Parallel (BSPP), Taper Thread (BSPT), UN/UNF/UNC Thread,
NPT (National Pipe Thread)
Serrations:
• MWD
Tolerances:
• Contact API’s engineering department for exact specifications and tolerances.
Plastic: Delrin, POM, Lexan, Nylon 66, Nylon 6, PEEK, PP, PE, Acetal
Rubber: EPDM, Neoprene, Buna-N, Viton
Aluminum: A2011, A2024, A2017, A5052, A5056, A6061, A6063, A6463, A6082, A7075
Copper: 3600, 3604, 3771
Titanium: 1-28
Steel Series:
• Ductile Iron: ASTM A536
• Carbon/Mild Steel: A105, A36, A516-70, A572-50, etc.
• Stainless Steel:
- 300 Series – 303, 304, 304L, 316, 316L
- 400 Series – 420J2, 430, 434, 442
Special Metals: Hastelloy, Inconel, Incoloy, Duplex 2205, Super Duplex 2507, Chrome Steel, alloys, or their equivalents
Stock Finish, Spiral Serrated (Phonographic), Concentric Serrated, Smooth Finish, Cold Water Finish, MWD, Phonographic
Dipped, Nickel Plating, Zinc Plating (clear, yellow, black, red, blue), Super Agitine, Powder, Painted, Galvanized, Epoxy, Lacquer
Water/Wastewater, Irrigation, Agriculture, HVAC, Marine, Exhaust, Mining, Energy/Power Generation/Oil
Forming:
• Forged:
- Ring Rolling:
• Materials: Carbon Steel, Stainless Steel, Duplex
• Size: 2–202”
• Cast:
- Centrifugal Casting (Industrial):
• Material: Stainless Steel
- Continuous Casting:
• Material: Stainless Steel
- Sand Casting:
• Material: A536, Stainless Steel, Ductile Iron
Machining: Milling, Turning, Facing, Boring, Drilling, Tapping, Counter Sinking, Laser Cutting, Water Jet, Plasma Cutting
| Products | Type | Materials | Size Range |
|---|---|---|---|
| Flanges | Flat-Face, Raised-Face, & Plate: Slip-On/Ring Weld, Neck, Blind, Socket Weld, Orifice, Reducing, Threaded | See Materials List | 5–202″ |
| Gaskets | Molded, Extruded, sheet | EPDM, Buna-N, NBR, Non-Asbestos (GNA), Red Rubber (GRR), Viton | 5–60″ |
| Screens For Filters | Basket Screens and Cone Screens (Perforated, Mesh) | Galv. Carbon Steel, Carbon Steel, Stainless Steel | 6”D x 8’-H |
| Rings | Exhaust Rings (Marmon Flanges for DPF Filters) | Carbon Steel, Stainless Steel, Aluminum | 1–16” |
| Seamless Rolled Rings | Forged | Carbon Steel, Stainless Steel, Aluminum | 1–165” |
| Square Hole Rings | Repair Couplers | Carbon Steel, Stainless Steel, Galvanized, Epoxy Coated | 3–32” |
| Fabricated Assemblies | Weldments, Pipe Spools, Valve Bodies, Silencer Housings | Carbon Steel, Stainless Steel | 2–24” |
| Long/Short Radius Elbows | EN 10253-2–S235, P235GH–P265GH–P265NL and ASTM A234, WPB, WPC/ A420 WPL6, WPL3/ A860 WPHY52/ ASTM A234 WP11, WP22, WP5, WP9–16Mo3 | 304L & 316L Stainless Steel | (45° & 90°): OD: 21.3mm (1/2”)–3048mm (120”) WT: Up to SCH. XXS/160 |
| Miscellaneous | Tubesheets / Diffuser Plates / Baffles / Ferrules / Sleeves / Pins | Carbon Steel, Stainless Steel, Duplex | 5–104” |
Who we are
API International is a manufacturer and wholesale distributor of flanges, expansion joints, valves, other pipe fittings and custom fabricated parts. We offer a wide variety of AIS & imported flanges along with other industrial pipe fitting and accessories. Customers turn to us when they need quick delivery of parts and are looking for a higher level of customer service. Standard parts are stocked in one of our conveniently located warehouses for quick distribution throughout the United States.
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