Municipal Sector
AWWA Plate-Cut Flange Supply for Water and Wastewater
Municipal water and wastewater systems run on AWWA C207 plate-cut flanges and the lightweight ANSI cast iron pattern. Diameters are large, pressures are modest, and SA-516 Gr.70 and A36 plate are the working materials.
Industry Overview
How Water & Wastewater Piping Actually Looks
Water treatment plants, distribution mains, lift stations, and aeration basins share a common bolt pattern lineage. AWWA C207 Class B at 86 psi, Class D at 175 psi, Class E at 275 psi, and Class F at 300 psi cover the working pressures of nearly every municipal system in the country. Plate-cut construction from SA-516 Gr.70 and A36 keeps the cost in line.
Class 125LW lightweight steel flanges drop in against cast iron valves and fittings using the ANSI B16.1 pattern. This is the day-to-day stocking item for treatment plant work where Class 150 ASME would be both heavier and more expensive than the service requires.
Diameters from 4 inch through 144 inch are routine, with custom rolls available out to 203 inch when plant retrofits push the upper end of available sizing. Raw water intakes, effluent outfalls, and large distribution mains all live in this range. The plate-cut path is what makes the larger sizes economical at all.
Typical Flange Selections
What We Supply for Water & Wastewater
AWWA C207 Class D
Plate-cut hub flange, 4 to 144 inch
Standard 175 psi distribution and treatment piping
AWWA C207 Class E
Plate-cut hub flange, 4 to 96 inch
275 psi service in high head distribution
AWWA C207 Class F
Plate-cut hub flange, 4 to 96 inch
300 psi force mains and pump discharge
Class 125LW Lightweight Steel
ANSI B16.1 bolt pattern, plate-cut
Drop-in replacement for cast iron at low pressure
Blind Flanges
AWWA pattern, Class D and E, plate-cut
Vault terminations and future tie-in points
Plate Ring Flanges
Flat ring, AWWA pattern, A36 or SA-516
Tank nozzles and lower pressure connections
Material Selection
Common Materials and Why
SA-516 Gr.70 Plate
Pressure vessel quality carbon plate for AWWA hub flanges. Standard for the higher classes and larger diameters.
A36 Carbon Plate
Structural carbon plate for lower pressure rings, blinds, and tank nozzle flanges where SA-516 is overspec.
ASTM A105 Forged Carbon
Forged option where ASME B16.5 sizing is specified for higher pressure plant interfaces and chemical feed.
316L Stainless
Chlorine contact chambers, chemical feed systems, and brackish water at coastal plants.
Industry Challenges
What Procurement Has to Solve
- 01
Matching AWWA bolt patterns to existing cast iron valves and fittings without re-drilling on site.
- 02
Large diameter lead times that drag if not stocked, especially above 60 inch on Class E and F.
- 03
Coating requirements for buried and submerged service, often fusion bonded epoxy or coal tar epoxy.
- 04
Chemical feed lines that demand stainless even though the plant runs carbon plate everywhere else.
Standards and Codes
Specifications We Quote To
Ready to Quote Water & Wastewater
Plant retrofits and large diameter mains are our daily work. Send drawings and we will quote AWWA plate-cut from stock.
PO Box 2889, Pearland TX 77588