Logic elements

Sun Hydraulics offer a wide range of corrosion resistant logic elements: pressure compensating, balanced, unbalanced logic elements and logic elements with position indicator. Stainless steel cartridge valves are the optimal choice for corrosion-prone environments, such as marine applications, where the risk of rust and material degradation is high. The valves are available either in stainless steel or in standard steel with a zinc-nickel surface treatment that provides effective corrosion protection. SUN Hydraulics stainless steel valves have been salt spray tested for a minimum of 1,000 hours in accordance with quality standards ASTM B117-03 and ISO 9227.

Valve based on certain logical conditions

A logic element (logic valve) is a type of valve used to control flow or pressure based on certain logical conditions – “if this happens, then do that.” It functions similarly to a logic gate, where a control signal determines how the logic element will respond. Logic elements are often used to build hydraulic control logic without electronics, making the systems robust and reliable, even in demanding environments. These valves can be used in a wide range of hydraulic systems and when combined with other valves, can create functions for directional, flow and pressure control. They are available in both balanced and unbalanced versions, depending on the application requirements.

Balanced and unbalanced logic elements

Balanced logic elements are not affected by pressure variations in the system and are controlled solely by the pilot/control pressure. They are used when it is important to ensure that the valve can be opened or closed independently of load, such as in hydraulic presses and cranes where stable and precise control is required. Unbalanced logic elements, on the other hand, are influenced by both system pressure and load pressure. They are simpler and more cost-effective alternatives but offer lower accuracy. One advantage is that they do not require an external pilot source – the load pressure can be used to control the valve.

Monitored and safety classified logic elements

A logic element with position switch provides feedback in the form of an electrical signal indicating whether the valve is in the open or closed position. These valves are commonly used in applications where personal safety is critical or where compliance with machine and safety standards is required. They are frequently found in industries such as steel mills, paper mills, power plants, and other facilities with safety or work cells, where reliable feedback is essential. Logic element with position switch elements can, for example, confirm that a function is fully switched off during maintenance or be used as emergency shutdowns in safety systems.

Possibility for complex systems

Logic elements can be controlled by multiple pressure signals, allowing for the construction of more complex systems based on logical principles, similar to electrical logic gates. Logic elements are used, among other things, to assemble directional valve functions for large flows. The engineers at Hydnet are experts in advanced and intelligent hydraulic systems. Feel free to contact us – we would be happy to help you design a system tailored to your specific needs.