AWWA C504

Covers — rubber-seated butterfly valves, 3–72 in., with various body and end types, for raw/potable/reclaimed water and wastewater within a defined pH and temperature range, for isolation and throttling.

Does NOT cover (exclusions) — the following are governed elsewhere:

• Resilient-seated water gate valves → AWWA C509 / C515.
• Process (hydrocarbon/high-temperature) butterfly valves → API 609.
• The connecting pipe/fittings → AWWA C151 / C200 / C110.

C504 is the waterworks butterfly valve; process service uses API 609 with different seat/rating logic.

C504 sets minimum requirements for water butterfly valves:

• Design — disc/shaft/body construction with a rubber seat for tight shutoff.
• Pressure Class — waterworks pressure classes matched to the service.
• Materials & Coating — corrosion-protective materials/finishes for water service.
• Testing — shell and seat (drop-tight) testing and operability of the actuator.

AWWA C504 is the standard rubber-seated butterfly valve for water service, 3–72 in., used for isolation and throttling on larger water mains and in treatment plants. Its rubber seat provides tight shutoff on water at low-to-moderate pressure, and at large sizes it is far more compact and lighter than a gate valve.

It is the waterworks counterpart to the process API 609 butterfly valve, with pressure classes and construction tailored to water quality and temperature limits. The companion resilient gate valve for water is AWWA C509.

Engineering Note: C504 butterfly valves throttle well but the disc sits in the flow path even when open — account for the pressure loss and, for pig-launched or full-bore requirements, confirm whether a gate valve (C509/C515) is needed instead.