How to Select the Right Pressure Relief Valve for a Hydraulic System

Pressure control valves are used to limit and regulate pressure within the functions of a hydraulic system. Pressure relief valves are commonly used as a safety valve to ensure that pressure does not exceed a predetermined limit. Pressure spikes can occur due to external factors such as loads and temperature, potentially causing system failure and component damage. The most common types of pressure relief valves are direct-acting or pilot-operated.

Direct-Acting Pressure Relief Valves – Fast Response Time

For quick reaction to pressure spikes, direct-acting valves are a solid choice. They are ideal for cutting off sudden spikes in pressure, such as external shocks to actuators. These valves are durable in demanding environments and less sensitive to oil contamination. In this category, the RDDA model is a commonly used option and is available in multiple sizes.

Pilot-Operated Pressure Relief Valves – Stable Pressure Levels

Need reliable pressure control with varying flow rates? Sun’s pilot-operated valves are easy to adjust under pressure thanks to their two-stage design. These valves maintain a consistent pressure level and have low pressure drop relative to flow. The RPEC valve offers robust protection for your system. It is an excellent standard valve for pressure control in applications with variable flow and works well as a system pressure limiter. They are available in various sizes.

Balanced Poppet Pressure Relief Valves – Fast Response and Easy Adjustment

These valves are similar to other pilot-operated types but offer added benefits such as low leakage and high precision. The RPES valve combines the best of both worlds: fast response like a direct-acting valve and fine-tuned control like a pilot-operated one. RPES valves are easy to adjust under pressure, smooth, quiet, fast, and have a low pressure drop relative to flow. They are available in various sizes.

Electrically Controlled Proportional Pressure Relief Valves – Stepless Proportional Control

Electrically controlled proportional valves are available in both direct-acting and pilot-operated versions. Unlike traditional valves, they offer stepless proportional control. Sun’s latest electrically controlled proportional valve, RPEI, provides accurate control and unmatched precision. RPEI features an inverted function—without power to the solenoid, it delivers maximum pressure. Increasing current lowers the set pressure.

It is designed for demanding drive circuits and enhances the performance of your hydraulic system. They are available in various sizes.

Unloading and Pressure Relief in One

The electrically operated RVCK valve includes both a manually adjustable pressure relief setting and a full unloading mode for bypass flow. This versatile valve combines the functions of an adjustable pressure relief valve and an unloading valve in a compact solution.

Contact us and we’ll help you find the right solution!