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How Pressure Regulating Valves Work

Find out the functioning and importance of water pressure regulators or unloader valves


How Pressure Regulating Valves Work

In the world of industrial washing, accurate water pressure management is essential to ensure safe and efficient operations. Unloader valves or water pressure regulators play a pivotal role in this context. But how exactly do they work, and what are their main functions? This article aims to explore in detail the functioning and significance of water pressure regulators or unloader valves.

What is a Water Pressure Regulating Valve?

A pressure regulating valve or unloader valve is a device designed to stabilize water pressure in a system, keeping it within a safe and desired pressure level.

These devices have a long and significant history, with evolving technology allowing for increasingly precise and reliable pressure adjustment over time. Compared to other pressure control methods, these valves offer a simple and efficient solution that has become indispensable in many industrial applications.

How the water pressure regulating valve works

The pressure regulating valve or unloader valve operates based on the principle of a proportional valve directly actuated by a spring. This valve is continuously adjustable, and the valve body is made of forged brass, a material known for its sturdiness and corrosion resistance. Stainless steel body valves are also available.

Depending on the volume of water consumed and the pressure set on the spring, the valve opens a section to the bypass, diverting excess water to the pump's inlet. When no water is consumed, the valve's bypass function is activated, redirecting the entire water flow to the inlet of the pump, thus preventing overloads and potential system damage.

What's the difference between a water pressure regulating valve and an unloader valve?

  • Unloader valves: they allow for the adjustment of the system's working pressure. When the delivery is closed, water is diverted in bypass, and the pump operates at low pressure. Typical applications are systems where the usage conditions involve frequent openings and closings of the delivery with prolonged periods in bypass mode.
  • Pressure regulating valves: they adjust the system's working pressure but, unlike unloader valves, the pump continues to operate at high pressure when the delivery is closed. They are also available in a pneumatic control version (VRPP) for remote pressure adjustment. Typical applications are systems with multiple outlets fed by the same valve or systems that do not frequently close the delivery.

Tips for Proper Use of These Valves

Valve adjustment is done once the water delivery unit is fully assembled. With changes in the nozzle size, the setting must be redone, emphasizing the importance of proper maintenance and system verification.

The pressure regulating valves or unloader valves should always be used in conjunction with safety or discharge valves, which are normally calibrated at a pressure that is 10% or 20% higher than the working pressure and intervene only in case of overpressure or malfunction of the unloader valve.

Use of Water Pressure Regulating Valves in the Industrial Field

The pressure regulating valves or unloader valves are essential in high-pressure water-fed systems, such as high-pressure washers. They help ensure all system components are coordinated in terms of pressure, providing a critical line of defense against overloads and potential damage to components and operators.


Water pressure regulating valves or by-pass valves are indispensable devices to maintain water pressure within safe and manageable limits across a wide variety of industrial applications. Understanding their functioning is crucial to ensure the safe and efficient operation of high-pressure systems. These components prove to be essential in many sectors, helping to prevent overloads, malfunctions, and potential hazardous situations, while at the same time ensuring efficient water resource management.

In particular, amidst the vast landscape of available solutions for pressure and flow control, the products offered by Emiltec stand as a quality choice. With a range of valves and flow regulators designed to meet the specific needs of industrial applications, Emiltec is committed to providing reliable and long-lasting solutions. For instance, Emiltec's pressure regulators are designed to ensure precise pressure control, ensuring easy maintenance and prolonged operational longevity at the same time.

Emiltec's vast knowledge and experience in the sector enable us to offer products that not only meet functional requirements but also provide added value in terms of technical assistance and continuous support. Choosing a reliable partner like Emiltec for the critical components of your high-pressure systems represents an investment towards safer and more efficient operation.