Butterfly valves are a cornerstone of modern fluid control, prized for their compact design, cost-effectiveness, and efficiency. Among the various types available, the lined butterfly valve stands out as a specialized solution designed to withstand aggressive or corrosive process media. By incorporating a protective lining on internal surfaces, these valves provide superior chemical resistance while maintaining reliable performance across a wide range of industrial applications.
Used to regulate or isolate flow, lined butterfly valves feature a central rotating disc as the closure mechanism. This disc is connected to a shaft that runs through the valve body and is actuated manually or automatically via handles, gears, pneumatic, hydraulic, or electric actuators.
Lined butterfly valves operate on a quarter-turn mechanism—a simple 90° rotation of the disc fully opens or closes the valve. They can also be partially opened for throttling purposes, especially when combined with positioners or modulating control devices, offering precision control for demanding flow regulation scenarios.
Lined butterfly valves are constructed with an internal lining material, such as PTFE (Teflon), PFA, FEP, EPDM, or Viton, to protect the valve body and disc from direct contact with process media. This lining acts as a corrosion-resistant barrier, making the valve suitable for aggressive chemicals, acids, alkalis, or high-purity applications where metal contamination must be avoided.
The lining is typically bonded or molded to the valve body and disc surfaces, ensuring leak-proof protection and long-term reliability, even under harsh operating conditions.
Lined butterfly valves are available in two primary body styles—wafer-type and lug-type—each suited for different installation requirements.
Designed to be sandwiched between two pipe flanges.
Lightweight and compact—ideal for systems with space or weight constraints.
Secured using through-bolts that pass through the flanges and valve body.
Cost-effective and easy to install.
Feature threaded lugs (inserts) around the valve body for direct bolting.
Allow one side of the piping system to be disconnected without affecting the other—ideal for dead-end service.
Provide a more secure and isolated mounting option.
Common in systems requiring frequent maintenance or section isolation.
Both types can be manufactured with full-face or tapped-lug designs to meet different pipeline standards and flange specifications.
The lined butterfly valve operates by rotating a circular disc mounted on a shaft inside the flow passage. When fully open, the disc aligns parallel with the flow direction, allowing minimal obstruction. When closed, the disc rotates perpendicular to the flow, effectively sealing the valve and stopping fluid movement.
The lining material ensures that the fluid never comes into contact with the metal valve body, offering high corrosion resistance and extending the service life of the valve. This makes lined butterfly valves particularly suitable for chemically aggressive environments.
Lined butterfly valves can also be used for throttling—adjusting the valve to intermediate positions for flow regulation. For automated systems, precise flow control is achieved with the help of:
Pneumatic or hydraulic actuators paired with positioners.
Electric actuators with modulating control boards.
Lined butterfly valves are widely adopted across industries requiring reliable, corrosion-resistant flow control. Common applications include:
Chemical and petrochemical processing
Pulp and paper production
Pharmaceutical and food-grade systems
Water and wastewater treatment
Power generation and HVAC
Marine and offshore systems
Acid and caustic transfer lines
Gas scrubbers and chlorine systems
These valves are particularly suited for applications where:
Corrosive media like sulfuric acid, hydrochloric acid, sodium hypochlorite, or solvents are present.
Sanitary or hygienic conditions are mandatory.
Metal-free flow paths are required.
The most significant advantage is the valve’s resistance to harsh chemicals and corrosive fluids. Linings such as PTFE, PFA, or EPDM provide excellent protection even in highly aggressive environments.
Modern lined butterfly valves deliver tight shutoff, minimizing leakage even under low-pressure conditions. This is essential for preventing contamination or fluid loss.
Compared to other valve types (such as diaphragm or ball valves in chemical services), lined butterfly valves offer an economical solution with lower installation and maintenance costs.
Thanks to their quarter-turn mechanism and compact footprint, lined butterfly valves are easy to install, even in tight spaces or suspended piping systems.
The non-metallic lining reduces wear, minimizes corrosion, and extends the operational life of the valve—resulting in long-term cost savings.
A wide selection of seat and lining materials (EPDM, Teflon, Viton, etc.) enables compatibility with various media and processes. FDA-approved materials are also available for sanitary applications.
Lined butterfly valves are available in a variety of sizes, pressure classes, and styles to meet different engineering and industry standards.
Body Styles: Wafer and lug
Seat Materials: EPDM, Viton, Teflon (PTFE), NBR, and others
Lining Materials: PTFE, PFA, FEP, or rubber compounds
Pressure Classes: ANSI 150, 300, 600, or equivalent
Size Range: Typically from 2 inches (DN50) up to 48 inches (DN1200), depending on the manufacturer
Face-to-Face Standards: API 609, ISO 5752, EN 558
Flange Compatibility: ASME B16.5, EN 1092-1, JIS, DIN
Valves designed for dead-end service are built to withstand full pressure from one side even when the opposite flange is removed—a key requirement for many maintenance-intensive applications.
Lined butterfly valves are not designed for high-pressure systems. They are generally used in low-to-medium pressure applications, and while they excel in corrosion resistance, they have lower pressure ratings than other types, such as:
High-performance (double-offset) butterfly valves: Designed for higher pressure and temperature applications.
Triple-offset butterfly valves: Provide metal-to-metal seating for critical isolation in steam, oil, or gas pipelines.
However, for corrosive or sanitary applications, the lined butterfly valve is often the best-suited option due to its chemical resistance and leak-proof design.
Actuation and Automation Options
Lined butterfly valves can be operated manually via a handle or gear box, or automated for remote or process-integrated control using:
Pneumatic actuators
Hydraulic actuators
Electric actuators
For automated systems, accessories such as:
Positioners
Limit switches
Solenoid valves
Modulating control boards
are added to provide feedback, flow control, or system integration into PLC, SCADA, or DCS platforms.
To ensure optimal performance and longevity of lined butterfly valves:
Handle with care during installation to avoid damaging the lining.
Align the valve precisely between flanges to prevent uneven loading or twisting.
Avoid overtightening flange bolts, which could deform the liner or disc.
Periodically inspect for signs of liner degradation, especially in aggressive chemical environments.
Flush the system when changing process media to prevent chemical incompatibility.
Following manufacturer guidelines during installation and operation is essential to avoid premature failure or performance loss.
The lined butterfly valve is a vital solution for industries requiring precise, corrosion-resistant flow control. Its unique design—combining the simplicity of butterfly operation with chemically resistant lining—offers a dependable and cost-effective alternative to more complex valve types.
Whether used in chemical processing, water treatment, food-grade systems, or marine applications, lined butterfly valves deliver durability, safety, and performance—making them a top choice for engineers and operators alike.
With growing demand for reliable fluid handling under challenging conditions, the lined butterfly valve remains a preferred choice for efficient and long-lasting operation.
