What Is an ANSI Valve?
An ANSI valve is a valve designed and manufactured to the dimensional and pressure-rating standards of the American National Standards Institute (ANSI). Because the face-to-face dimensions, flange drillings and pressure classes are standardised, an ANSI valve can be installed in any piping system built to the same standard, regardless of the manufacturer. Sizes are expressed in inches (for example 1/2″, 2″ or 24″) and pressure ratings in classes such as Class 150, 300, 600, 900, 1500 and 2500.
ANSI valves are not a single valve design but a family of valve types built to the same standard. They can be operated manually or automatically and can be combined with a wide range of actuators.
Common ANSI Valve Types
- ANSI ball valve
- ANSI butterfly valve
- ANSI check valve (swing, tilting disc and piston types)
- ANSI gate valve
- ANSI globe valve
Depending on the design and pressure class, these valves are produced in cast steel or forged steel bodies. Forged steel is typically used for smaller sizes and the highest pressure classes, while cast steel covers the larger bore sizes.
Working Principle
The working principle depends on the valve type. Quarter-turn designs such as ball and butterfly valves open and close the flow with a 90° rotation of the ball or disc. Gate and globe valves use a linear movement of the closing element, while check valves open automatically with forward flow and close against reverse flow. In every case, the closing element seals against a seat to shut off or regulate the medium.
Technical Features
Luna Flow Control supplies ANSI valves in steel, stainless steel and other materials, with flanged, socket-weld/butt-weld (SW/BW) or threaded end connections. Operation is available by lever, gearbox, or electric, pneumatic or hydraulic actuator. The range covers nominal sizes from 1/2″ to 48″, pressure classes from Class 150 to Class 2500 and operating temperatures from -200 °C to +700 °C.
Application Areas
ANSI valves are used wherever piping is designed to American standards, including oil and gas, chemical processing, power generation and water treatment plants. Typical applications include:
- Chemical industry
- Food industry
- Shipbuilding
- Natural gas installations
- Heating and cooling systems
Advantages
- Interchangeability: standard dimensions simplify replacement and spare-part supply.
- Wide rating range: suitable for low-pressure utilities as well as high-pressure, high-temperature service.
- Flexible configuration: a choice of materials, end connections and actuators for each application.
Selection Tips
The weight and final configuration of an ANSI valve depend on the body material, size and pressure class, so there is no single standard weight. When selecting a valve, always check the maximum operating pressure and temperature of the line and choose a pressure class rated for these conditions. Providing full details of the medium, operating conditions and connection type allows Luna Flow Control to recommend or custom-build the most suitable valve for your system.
