Discover Applications of Flanged and Lug Butterfly Valves

Flanged Butterfly Valves

A Flanged Butterfly Valve is installed between two pipe flanges and secured with bolts passing through the valve body. Gaskets are normally installed between the valve and pipeline flanges to provide a tight seal.

This design is commonly used where a stable and rigid connection is required. It is suitable for water treatment plants, pump stations, cooling water systems, irrigation pipelines and industrial process lines.

A Double Flanged Butterfly Valve has integral flanges on both ends of the valve body. This construction is widely used on larger-diameter pipelines, particularly in municipal water and wastewater applications. It is also suitable for long pipeline sections where a strong and fixed connection is required.

For waterworks and underground installations, Ductile Iron Flanged Butterfly Valves are a popular choice. Ductile iron provides good mechanical strength and impact resistance, while epoxy coating helps protect the valve body against corrosion.

For applications where simple manual operation is sufficient, a Manual flanged butterfly valve can be fitted with a lever or worm gearbox. Gear-operated valves are especially useful on larger sizes where the operating torque is too high for direct lever operation.

Lug Butterfly Valves

A Lug Butterfly Valve has threaded inserts or lugs around the valve body. Each side of the valve is bolted separately to the corresponding pipe flange.

One major advantage of the lug design is its suitability for dead-end service. In many applications, the downstream pipe can be removed while the valve remains attached to the upstream side. This makes lug valves useful for equipment isolation, tank connections, pump systems and pipelines that require regular maintenance.

The independent bolting arrangement also makes lug valves convenient where sections of the piping system need to be removed or replaced.

A Pinless Lug Butterfly Valve uses a stem-to-disc connection without conventional pins. The pinless design reduces the number of exposed connection points and can help reduce potential leakage and corrosion problems around the disc and stem connection. It also simplifies maintenance and component replacement.

For corrosive media, a Pinless PTFE Lined Butterfly Valve can be supplied with a PTFE seat and corrosion-resistant disc coating. It is suitable for many chemical applications involving acids, alkalis, solvents and other aggressive fluids.

Grooved Butterfly Valves

For projects where fast installation is important, a Grooved Butterfly Valve offers another practical solution. The grooved ends connect directly to mechanical couplings, eliminating the need for welding or conventional flange connections.

Ductile Iron Grooved Butterfly Valves are widely used in fire protection, HVAC, chilled-water systems and building services. They are particularly useful in retrofit projects where installation time and working space are limited.

Soft-seat construction provides reliable shutoff for many water-based applications, while a lever operator allows quick manual operation on smaller valve sizes.

Coated Disc Butterfly Valves

For abrasive fluids and slurry service, standard soft-seat butterfly valves may not provide sufficient wear resistance. A Coated Disc Butterfly Valve can be used where the disc and seating area require additional protection.

Depending on the coating material and valve construction, these valves can be used in mining, pulp and paper, power generation and other applications involving abrasive or corrosive media.

The coating selection should be based on the actual fluid, temperature, pressure and abrasive conditions rather than simply choosing the coating with the highest nominal resistance.

High Performance Butterfly Valves

For higher pressure, higher temperature or frequent cycling applications, High Performance Butterfly Valves provide a more advanced alternative to standard concentric butterfly valves.

Double-offset and triple-offset designs reduce contact between the disc and seat during operation. This can lower operating torque, reduce seat wear and extend service life.

Depending on the application, high-performance valves can be supplied with resilient, PTFE or metal seats. Triple-offset metal-seated butterfly valves are often selected for demanding industrial services where temperature and cycle requirements exceed the capability of conventional soft-seat designs.

Motorized Butterfly Valves

When the valve needs to be operated remotely, a Motorized Butterfly Valve can be equipped with an electric actuator. The actuator can be connected to a PLC, DCS or building management system for remote open/close control or automatic flow regulation.

Motorized butterfly valves are commonly used in water treatment, district cooling, HVAC, process systems and automated pumping stations.

The actuator should be selected according to valve torque, operating frequency, power supply, control signal and environmental conditions.

Butterfly Valves and Backflow Protection

A standard butterfly valve is mainly used for isolation and flow control. It should not be treated as a dedicated backflow prevention device.

Where reverse flow must be prevented automatically, a Butterfly Check Valve or another suitable check valve should be installed according to the pipeline design. Check valves operate automatically when the flow direction changes and do not require an external operator.