A stainless steel butterfly valve is a compact, quarter-turn shut-off valve built from 1.4307 (304L) or 1.4404 (316L) stainless steel, designed to route low and medium-viscosity liquids through hygienic pipework with minimal flow restriction and a small face-to-face footprint. Designed for high-volume routing, these valves isolate pipe sections, divert product to tanks, or manage flow to fillers while keeping product paths crevice-free. This reliability makes them the default choice for the process engineers and procurement specialists who maintain production continuity in dairies, breweries, food plants, and pharmaceutical facilities.

Euroflow is the regional Alfa Laval Master Distributor for hygienic process components. We supply the full LKB butterfly valve family, allowing you to match specific requirements for ISO tubing, DIN tube sizes from NW25 to NW150, or flange connections. For high-purity duties, the UltraPure variant ensures full transparency with documentation, while our Leakage Detection model provides mixproof integrity for CIP and water management circuits. Each sanitary butterfly valve in the range can be customized with pneumatic LKLA actuators, manual handles with multi-position locking, and ThinkTop sensing and control units to integrate with plant automation systems.

Across the range, material selection is critical to production uptime. You can specify product-wetted seals in EPDM, FPM, HNBR, Q (silicone), or PFA to suit various cleaning parameters and product temperatures. Whether you are scoping replacement parts for an LKB-2 installation or designing a new beverage skid, the data provided here establishes the technical specification required for precise flow management. By choosing the correct actuation and seal combination, plants can reduce total cost of ownership while maintaining uncompromised product integrity.

The Alfa Laval LKB family covers four main variants of stainless steel butterfly valve, each engineered for a specific hygienic duty. All variants share the same architecture consisting of two valve body halves, a disc, bushings, and a seal ring. They differ in connection standards, surface finishes, and documentation packages.

LKB and LKB-2 standard butterfly valves

The LKB is the primary variant for routing low and medium-viscosity liquids. The LKB suits ISO tubing standards, while the LKB-2 covers DIN tube sizes such as NW25, NW40, and up to NW150. These valves handle a maximum inlet pressure of 1000 kPa (10 bar). For manual operation, they utilize a standard handle with spring-locking action. For automation, they pair with LKLA actuators in ø85 mm or ø133 mm sizes.

LKB-F flange version

The LKB-F incorporates two flanges and two flange seal rings. This design allows for the easy removal of the valve body without dismantling extensive piping setups. It is a preferred choice in large-scale dairy or brewery plants where maintenance speed is vital. When using HNBR or PFA seal materials in the LKB-F (DIN), they are supplied with an EPDM flange seal.

LKB UltraPure for high-purity applications

The LKB UltraPure is designed specifically for biotechnology and pharmaceutical industries. Product-wetted steel parts are 1.4404 (316L) with internal finishes ranging from 0.5 µm (SF1) to 0.4 µm electro-polished (SF4). These valves are delivered with Alfa Laval Q-doc for full supply chain traceability. Seals comply with FDA and USP Class VI standards, ensuring biocompatibility for critical process lines.

Leakage Detection Butterfly Valve

This model prevents cross-contamination between product and cleaning media. It features a disc with a leakage chamber and a seal, allowing any accidental leakage to be visible immediately. It is typically used in CIP/SIP systems and flush-out processes where safeguard hygiene and maximizing uptime are mandatory.

Sanitary butterfly valves appear at flow-direction changes and tank-to-tank intersections in nearly every high-purity processing environment. Their substantial opening area and low flow resistance make them essential for both raw product intake and finished product distribution.

Upstream and downstream integration

In a typical process line, butterfly valves are placed upstream to isolate raw storage tanks and manage receiving manifolds. Downstream, they control flow to heat exchangers, separators, and filling lines. In dairy applications, they often isolate the pasteurizer while product is transferred. In breweries, they are found on the wort line out of the kettle and on fermentation outlets feeding bright beer tanks. The compact design allows these valves to be clustered in valve matrices, reducing the overall footprint of the intake and output skids.

Material requirements by sector

While the LKB family is modular, industry requirements dictate specific configurations. Dairy processes favor EPDM product-wetted elastomers because they withstand continuous steam and acid cleaning cycles up to 140 °C. Beverage and brewery applications frequently operate in potentially explosive atmospheres, requiring ATEX-classified equipment. The LKB range carries a II 2 G D1 classification. Food producers handling fatty products—such as dairy desserts or sauces—must specify FPM or HNBR because EPDM is not resistant to organic and non-organic oils and fats. For the personal care and pharmaceutical industries, LKB UltraPure valves meet high hygiene standards through internal finishes of Ra ≤ 0.5 μm and seals compliant with FDA and USP Class VI.

CIP and SIP system duties

The Leakage Detection Butterfly Valve is engineered for Cleaning-in-Place (CIP) and Sterilization-in-Place (SIP) systems. In these circuits, the valve prevents cross-contamination by providing a atmospheric leakage chamber between two media. If a seal fails, the leaked liquid drains through the disc's leakage chamber rather than mixing with the opposite flow. This mixproof security is standard in water management and flush-out processes where product integrity cannot be compromised. Operators can monitor these critical points using ThinkTop units for real-time status feedback.

Operating principle and core components

A stainless steel butterfly valve is a quarter-turn valve that utilizes a disc to stop or permit flow. The disc is a circular plate mounted on a central stem. Rotating the disc 90° closes the valve as the disc rim presses against a resilient seal ring fitted in the body. When open, the disc lies parallel to the direction of flow, providing a thin profile that minimizes pressure drop. The LKB design consists of two valve body halves, the disc, bushings for the stem, and the seal ring, all assembled with screws and nuts for straightforward maintenance.

Product-wetted steel parts are manufactured from 1.4307 (304L) or 1.4404 (316L). The bushings are made of PVDF to isolate the stem and ensure a long service life. The valve’s torque increases as the disc comes into contact with the seal ring, securing proper closing of the valve seat. For automated routing, the pneumatic actuator converts axial piston motion into this 90° rotation.

Selection factors for LKB valves

Selection begins with matching the valve size to the pipeline diameter. The LKB range covers sizes from 25 mm/DN25 up to DN150. Engineers must consult capacity/pressure drop diagrams, usually based on water at 20 °C in accordance with VDI 2173, to ensure the valve meets flow requirements. Sizing also involves verifying inlet pressure limits (1000 kPa) and temperature constraints based on the elastomer selected.

Seal material choice is dictated by the chemical and temperature exposure. EPDM is standard for dairy and beverage due to its 140 °C resistance to CIP acids/lye, though it fails in the presence of oils. FPM handles high fats and oils up to 180 °C. HNBR is mechanically strong and resistant to ozone. Q (Silicone) remains elastic from below -50 °C up to +180 °C. PFA is preferred for abrasive duties with high mechanical strength up to 90 °C.

Actuation and automated control

Manual operation is performed via handles available in two-position, four-position, or multi-position configurations. For automated systems, the LKLA actuator is the standard choice. It comes in three standard versions: normally closed (NC), normally open (NO), and air/air activated (A/A). These can be upgraded with ThinkTop V50 or V70 units for sensing and control. Alternatively, the Unique Control LKB offers a maintenance-free, intelligent actuator with an integrated control unit, tested for over one million strokes and compatible with PLC systems using digital or AS-Interface communication.

Butterfly vs. Ball and Diaphragm valves

The sanitary butterfly valve is the most cost-effective shut-off solution for low to medium-viscosity liquids, offering a compact footprint. However, the disc remains in the flow path even when open. A sanitary ball valve (SBV) provides a full-bore diameter for zero restriction, which is non-negotiable for high-viscosity products, liquids with large particles, or pigging recovery systems. Diaphragm valves, like the Unique DV-ST, are reserved for aseptic duties where a flexible diaphragm must completely isolate the stem from the product zone to prevent microorganisms from entering. While the butterfly valve is the economical standard for general hygienic routing, ball valves are required for obstruction-free bores, and diaphragm valves for maximum sterility.