Flange dimensions and weights to AWWA C228 standard. Every size we list is one we manufacture and ship, with custom sizes and modifications available on request.
Instant per-flange weight
Sizes, counts, lengths
Dimensional tolerances
Request a Product Catalog
Select a pressure class to view its dimension tables, including outside diameter, inside diameter bolt circle, number and size of bolt holes, thickness, and weight.
Each table lists, per nominal size: outside diameter, inside diameter, bolt circle, number and size of bolt holes, thickness, and weight. Dimensions and weights follow the AWWA C228 standard, and every C228 flange uses the ASME/ANSI Class 150 bolt pattern.
We manufacture to your specifications and stock domestic AIS/Buy America and imported materials, with galvanized, epoxy, and additional coatings available. Rubber expansion joints and gaskets are also supplied on request.
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 municipal pipelines, treatment plants, irrigation systems, and other applications up to 300 psi.
The American Water Works Association (AWWA) provides two main standards for flanges for water-work applications:
These standards also define dimensions, drilling patterns, pressure ratings, and material properties.
AWWA C207 covers carbon steel flanges, while AWWA C228 covers stainless steel flanges for the same applications. Both define dimensions, pressure classes, and material requirements.
Not directly. In many sizes the two share the same drilling, so they often bolt together, but AWWA C228 is stainless steel and C207 is carbon steel, and each standard sets its own thickness and pressure details. Match the standard, class, and material to your service before substituting one for the other.
Pressure ratings vary by class:
These ratings apply to water service and depend on flange size and material.
API International stocks AWWA C228 flanges across multiple nominal pipe sizes, pressure classes, and material options to meet your project requirements. Our machine shop can also modify stock products to accommodate any special project requirements. Contact API International’s experienced sales team, and we will help you select the right flange for your application.
