Shock valves, single-acting

A single-acting shock valve is a vital component in hydraulic systems, with its main function being the absorption of pressure spikes. It protects expensive hydraulic components, particularly hydraulic motors and cylinders, against damage caused by sudden shock loads or overpressure events. The valve operates in one direction only and safely relieves excess pressure once a preset value is exceeded.

The key difference of a single-acting shock valve is its unidirectional mode of operation. It limits the pressure exclusively in the flow direction in which it is installed. In contrast, double-acting versions are required to absorb pressure spikes in both directions. This means that a single-acting valve is specifically designed to protect against pressure surges in a defined section of the hydraulic circuit.

Single-acting shock valves are widely used in systems subject to rapid or sudden pressure changes. They are often flange-mounted on hydraulic motors to provide protection during quick direction or load changes. In conveying and work machinery, they act as protection valves during sudden load variations. In cylinders and lifting drives, they provide safety against overpressure during rapid lowering or lifting. Their importance lies in avoiding costly damage while increasing operational safety and extending the service life of the entire hydraulic system.

• Mostly flange-mounted design for easy installation
• Consist of a high-pressure valve, optionally with integrated check valve
• Adjustment range: typically 30–250 bar
• Maximum flow rate: depending on design 60–120 l/min
• Manufactured from high-quality materials for long service life
• Optionally with integrated replenishing function for improved operational safety
• Common port sizes: G 1/2" or G 3/4"

Proper selection and installation are essential for the function and service life of hydraulic components. The valve should be mounted as close as possible to the component being protected. The adjustment must be precisely matched to the maximum expected system pressure and the specific application in order to ensure optimal protection and avoid undesired malfunctions.

Using a single-acting shock valve prevents costly damage from sudden pressure surges, increases operational safety, and significantly extends the service life of hydraulic motors and cylinders. It is therefore an indispensable element for preventive protection in many applications.

In general, single-acting shock valves are low-maintenance. Their robust design and high-quality materials ensure long service life. Nevertheless, regular functional checks are recommended to ensure the valve operates reliably when required.

No, single-acting shock valves are designed only to limit pressure spikes in one flow direction. For applications with pressure peaks in both directions, double-acting shock valves are required.