Municipal Sector
AWWA Flanges for Treatment, Distribution, and Collection
Municipal water and wastewater systems run on AWWA C207 flanges and the lightweight ANSI cast iron pattern. Diameters are large, pressures are modest, and budgets are tight.
Industry Overview
How Water & Wastewater Piping Actually Looks
Water treatment plants, distribution mains, lift stations, and aeration basins all 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.
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. Plant retrofits, raw water intakes, and effluent outfalls all push the upper end of available sizing. We supply municipal contractors, treatment plant maintenance, and large diameter pipeline projects from common stock.
Typical Flange Selections
What We Supply for Water & Wastewater
AWWA C207 Class D
Hub flange, 4 to 144 inch
Standard 175 psi distribution and treatment piping
AWWA C207 Class E
Hub flange, 4 to 96 inch
275 psi service in high head distribution
AWWA C207 Class F
Hub flange, 4 to 96 inch
300 psi force mains and pump discharge
Class 125LW Lightweight Steel
ANSI B16.1 bolt pattern
Drop-in replacement for cast iron at low pressure
Blind Flanges
AWWA pattern, Class D and E
Vault terminations and future tie-in points
Plate Flanges
Flat ring, AWWA pattern
Tank nozzles and lower pressure connections
Material Selection
Common Materials and Why
Carbon Steel Plate
AWWA C207 is fabricated from rolled plate. Cost effective at large diameters where forgings would be uneconomical.
ASTM A105 Forged Carbon
Used where ASME B16.5 sizing is specified for higher pressure plant interfaces.
316L Stainless
Chlorine contact chambers, chemical feed systems, and brackish water at coastal plants.
Ductile Iron
Some plant standards still call out ductile iron flanged fittings for buried service compatibility.
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.
- 03
Coating requirements for buried and submerged service, often fusion bonded epoxy.
- 04
Chemical feed lines that demand stainless even though the plant runs carbon 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 classes from stock.
Texas Flange & Fitting Supply | PO Box 2889, Pearland TX 77588