Accurate flange specifications are critical for proper system design, structural integrity, and regulatory compliance. Understanding weight and dimensional parameters ensures your piping system performs reliably and meets all AWWA, ASME, and ANSI standards.
The overall external diameter of the flange. This dimension determines the footprint and space requirements in your installation. Larger OD provides greater load distribution and structural support for high-pressure applications.
The inner opening that connects to the pipe or fitting. Bore diameter must match your pipe size and is critical for proper flow and pressure containment. Standard bore sizes follow NPS (Nominal Pipe Size) specifications.
The diameter on which bolt holes are positioned. BCD determines bolt spacing and is essential for proper fastening. Larger BCD provides better load distribution and reduces stress concentration at bolt attachment points.
The axial dimension perpendicular to the face. Thickness directly affects load-carrying capacity and weight. Lightweight flanges use optimized thickness to minimize weight while maintaining structural integrity under rated pressures.
The number of holes and their diameter are standardized by AWWA and ASME. Proper bolt sizing and spacing ensure even load distribution, prevent leakage, and guarantee reliable assembly without over-torquing or under-tightening concerns.
Flat-face or raised-face designs affect gasket seating and joint integrity. Face height impacts fluid volume in piping and is critical for certain applications. Lightweight flanges typically feature optimized face designs for specific pressure classes.
Proper dimensions ensure flanges withstand rated pressures and prevent catastrophic failure.
Accurate bolt patterns and spacing reduce assembly time and minimize field modifications.
Weight specifications guide material choices, balancing durability with cost and ease of handling.
AWWA C207, ASME B16.1, and ANSI specifications ensure interchangeability and safety.
Proper sizing minimizes waste, reduces unnecessary weight, and optimizes material usage.
Correct flange specifications prevent leakage, reduce maintenance, and extend service life.
Lightweight flanges (125 PSI rating) are ideal for low-to-moderate pressure water and wastewater applications. Below are typical dimensions for common sizes per AWWA C207 standards.
| NPS (Pipe Size) | OD (inches) | BCD (inches) | Bolt Holes | Thickness (inches) | Weight (lbs) |
|---|---|---|---|---|---|
| 4 | 9.50 | 7.50 | 4 x 0.625" | 0.625 | 3.2 |
| 8 | 15.25 | 12.50 | 8 x 0.75" | 0.75 | 9.8 |
| 12 | 20.00 | 16.50 | 8 x 0.75" | 0.875 | 17.5 |
| 16 | 24.00 | 20.50 | 12 x 0.75" | 1.00 | 27.3 |
| 24 | 33.00 | 28.75 | 12 x 0.875" | 1.125 | 48.6 |
* All dimensions per AWWA C207 standard. Weights are approximate and may vary by material grade. Contact Texas Flange & Fittings for complete specifications or custom sizes.
Lightweight flanges are optimized for lower pressures (typically 125 or 150 PSI), which allows reduced thickness and weight compared to heavier classes. If your system requires higher pressure ratings, heavier flange classes may be necessary.
Common materials for lightweight flanges include ductile iron and carbon steel. Material choice affects both weight and corrosion resistance. Consult with engineering to determine the best option for your application and environment.
OD and thickness dimensions determine the physical footprint required for installation. In tight spaces or congested valve vaults, lightweight designs provide significant advantages. Verify clearances early in your design phase to avoid costly field modifications.
Proper bolt sizing and hole positioning determine torque requirements. Over-torquing can crack flanges, while under-torquing causes leakage. Consult the manufacturer's installation guide for your specific flange weight and size.
Texas Flange & Fittings Inc. provides complete dimensional data, technical drawings, and expert guidance for selecting the right lightweight flanges for your project.
Email: sales@texasflange.com | Established 1986
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