Shock valves, double-acting

A double-acting shock valve is a hydraulic valve designed to limit pressure spikes in both flow directions of a hydraulic system. It safely relieves pressure at the ports of a hydraulic motor or cylinder once a preset maximum value is exceeded. This is particularly important during rapid changes in movement direction to prevent damage from sudden pressure surges.

Double-acting shock valves are used in systems where hydraulic motors, cylinders, front loaders, forklifts, and conveyor systems need protection against external forces and abrupt directional changes. They are commonly applied in mechanical engineering, agriculture, construction, and industry – for example, for smooth braking or safeguarding snowplow cylinders, lifting systems, and other hydraulic actuators, particularly in reversing movements.

• Maximum flow rate: 45–70 l/min
• Adjustment range: 50–250 bar (standard), up to 350 bar possible
• Port sizes: G 3/8" to G 1/2" female thread
• Material: Zinc-plated steel or steel housing
• Temperature range: Ambient -40°C to +60°C, oil -15°C to +80°C
• Additional functions: Integrated check valves to prevent cavitation and replenishing function

• System protection in both directions
• Protection against peak pressures regardless of force direction
• Fast response time
• Extended component life by preventing pressure surges and cavitation
• Low maintenance due to robust design

Installation can be flange-mounted or as a block valve, ideally directly on the hydraulic motor, cylinder, or manifold block to ensure direct pressure relief. Pressure adjustment is carried out via an adjustment screw or locknut. Valves are often factory-set to approx. 130 bar but can be adapted depending on the application. Mineral oil-based hydraulic fluids are recommended for operation.

With integrated check valves, double-acting shock valves prevent cavitation by releasing oil (usually to tank) during pressure spikes while simultaneously ensuring reliable replenishment. This keeps oil supply stable, supporting safe and continuous operation. Models with integrated replenishing function provide especially high protection.

While single-acting shock valves provide protection in only one direction, double-acting versions secure the system in both directions of movement. This is a crucial advantage for protection and operational safety, particularly with reversing actuator movements and under demanding operating conditions.

They protect hydraulic systems from sudden high pressure spikes that could damage components. The bidirectional pressure relief in combination with the replenishing function ensures stable and safe operation, especially in dynamic applications with changing loads and directions – significantly extending the service life of the entire system.