The Alfa Laval Unique SSV Two Step is a specialized two-step pneumatic valve designed to solve the challenges of rapid fluid displacement in hygienic lines. The valve utilizes an intermediate plug position within the actuator to manage flow in two distinct stages. This mechanical configuration is essential for precision dosing, where the final portion of a filling cycle must be slowed to reach an exact volume without overshooting. By controlling the speed and volume of the fluid transition, the valve manages kinetic energy to ensure product integrity throughout the cycle.

Water hammer mitigation in processing lines

To protect sensitive downstream equipment and piping infrastructure, the Unique SSV Two Step provides soft, controlled pressure surge reduction. The two-stage closing sequence acts as a dampening mechanism, preventing the force of water hammer that occurs when fluid flow is stopped abruptly. This function is vital in high-velocity filling applications where traditional single-stage valves might cause mechanical stress or seal failure. The actuator includes adjustable lifting height via spacer rings, allowing operators to match specific volumes and quantities to their exact process requirements.

Hygienic construction and seal integrity

Built as an extension of the Unique SSV platform, the Two Step version features a smooth inner valve body without crevices to ensure superior cleanability. Product safety is enhanced through a static seal leak detection system and a double lip seal that provides protection against full vacuum conditions. The valve seals are optimized for durability through a defined compression design, which extends service life by preventing over-stressing of the elastomers during high-frequency cycles. Whether configured as a shutoff valve with two ports or a changeover valve for draining two pipes at once, the design maintains strict hygiene across all configurations.