The AWWA C504 concentric double flange butterfly valve from Laux Valve is engineered specifically for municipal waterworks and industrial water applications. Built to the stringent AWWA C504 standard with a Class 125 pressure rating, this valve features a vulcanized rubber seat bonded directly to the ductile iron body and flat face flanges per ASME B16.1 Class 125/250lb for direct mating to cast iron flanged fittings and valves.
The vulcanized seat design eliminates the risk of seat movement, extrusion, or blowout under pressure, providing reliable bubble-tight shut-off over decades of service. The concentric design centers the disc on the valve bore axis, delivering consistent sealing with lower operating torque.
| Parameter | Specification |
| Size Range | 3" to 48" (DN80 to DN1200) |
| Type | Concentric Double Flange Butterfly Valve |
| Design Standard | AWWA C504, Table 1 (Class 125) |
| Body Material | Ductile Iron ASTM A536 65-45-12 |
| Disc Material | Ductile Iron |
| Seat Type | Vulcanized EPDM Rubber (bonded to body) |
| Seat Material | EPDM (Option: NBR / Hypalon / Viton) |
| Body Coating | Fusion Bonded Epoxy (FBE), min 250 microns |
| Pressure Rating | Class 125 (125 PSI / 8.6 bar) |
| Flange Type | Flat Face (FF) per ASME B16.1 Class 125 |
| Face-to-Face | AWWA C504 Short Pattern |
| Test Standard | API 598 / AWWA C504 |
| Temperature Range | -20°C to +110°C (EPDM) |
| Operation | Lever / Worm Gearbox / Pneumatic / Electric |
| Stem Material | 416 SS / 316 SS / 17-4PH |
| Mounting Pad | ISO 5211 (F14 - F40 depending on size) |
| Feature | Vulcanized Seat | Cartridge Seat |
| Seat Bonding | Chemically bonded to body | Mechanically retained |
| Blowout Resistance | Excellent — bonded seat cannot move | Good — relies on mechanical retention |
| Field Replacement | Factory re-vulcanization required | Field replaceable without special tools |
| Typical Life | 15-20 years | 8-12 years per seat |
| Best For | Waterworks, critical isolation | Chemical, frequent seat change |
Flat face flanges (ASME B16.1 Class 125) are the standard for cast iron flanged fittings in North American waterworks. The flat face design distributes the gasket load over the full flange face, reducing bending stress on cast iron mating components. Key advantages:
AWWA C504 is the American Water Works Association standard for Rubber-Seated Butterfly Valves. It covers design, materials, pressure ratings, testing, and dimensional requirements for butterfly valves used in water supply and wastewater systems. Valves meeting this standard are suitable for potable water, raw water, and wastewater service.
Class 125 (125 PSI) is a lower pressure rating primarily used in North American waterworks with cast iron flanged fittings. Class 150 (285 PSI) is a higher rating used with ductile iron or steel flanges. Class 125 valves use flat face flanges (ASME B16.1) while Class 150 use raised face flanges (ASME B16.5).
A vulcanized seat is a rubber lining that is chemically and mechanically bonded to the valve body during the molding process. Unlike loose or cartridge seats, a vulcanized seat cannot shift, extrude, or blow out under pressure. This provides maintenance-free operation and reliable bubble-tight shut-off for the life of the seat — typically 15-20 years in water service.
Yes. The double flange design supports full dead-end service at the rated pressure. The valve can be installed at the end of a pipeline with a blind flange and maintain bubble-tight shut-off. This is a key requirement for isolation valves in water distribution systems.
This valve can be supplied with NSF/ANSI 61 certification for drinking water system components in the US and Canada
For pricing, dimensional drawings, or actuator sizing, contact our sales team.
Email: james@lauxvalve.com | Tel: +86 18920833829
From raw material inspection to final delivery, every butterfly valve undergoes a comprehensive quality inspection to ensure reliable performance and compliance with international standards.
