Relief valves are essential components in industrial, commercial, and residential systems, designed to keep pressure under control and protect infrastructure and equipment from potential damage. The primary function of a relief valve is to release accumulated pressure when it reaches critical levels, thus preventing overpressure risks that can cause severe damage, including explosions.

With the market offering numerous models, choosing the right relief valve can be complex. The right decision will depend on multiple factors, which we will detail below, to ensure the relief valve meets the system’s requirements and provides optimal performance and safety.

Key Factors for Selecting a Relief Valve

When selecting a suitable relief valve, there are several critical factors that will ensure its proper functioning and safety within the system. These are the key elements to consider:

The size of the relief valve must match the size of the inlet and discharge pipes. Improper connections can affect the performance and safety of the system. For example, valves may have male or female NPT connections or be connected via flanges. Each of these options should be considered to ensure an optimal installation and prevent leaks.

The activation pressure adjustment is the point at which the relief valve opens to release pressure. This setting must be lower than or equal to the maximum allowable working pressure (MAWP) of the equipment. Generally, the system’s MAWP should exceed the expected operating pressure by at least 10%, thus ensuring a safety margin and allowing the valve to act before reaching dangerous levels.

The temperature of the fluid (whether gas or liquid) affects the choice of valve material. Materials like stainless steel withstand higher temperatures compared to bronze or iron, making them more suitable for certain systems. It is essential to evaluate both the operating temperature and the relief temperature to avoid material failures and prolong the valve’s lifespan.

Backpressure, or the pressure on the outlet side of the valve, is another important factor. The valve should be selected according to the type of backpressure present in the system: it can be constant or variable. In cases of variable backpressure, it should not exceed 10% of the set pressure. If necessary, a valve with a bellows seal or pilot-operated valve may be the best option to prevent damage.

The relief valve must be compatible with the type of medium it will operate in, whether steam, air, gas, or corrosive fluids. For example, stainless steel is ideal for corrosive services, while bronze may be suitable for less demanding applications. Choosing the right material ensures optimal resistance to the specific factors of each application.

The capacity of a relief valve is measured in terms of discharge flow (such as pounds per hour for steam, SCFM for air/gas, or GPM for liquids). The valve must be capable of handling the amount of pressure released according to the applicable code, adapting to the volume and speed of the medium that needs to be relieved to maintain safe pressure in the system.

Valvula de exceso de presión S1

Tips for Installing a Relief Valve

Proper installation of a relief valve is just as important as selecting the right one. Below, we provide essential recommendations to ensure the valve operates correctly and extends its lifespan within the system:

  • Pipe Cleaning
    Before installing the relief valve, it is essential to thoroughly clean the pipe to remove any debris or impurities that could block or damage the valve mechanism. Additionally, it is recommended to install a filter at the valve inlet to prevent the accumulation of particles and ensure a clean and continuous flow.

  • Valve Orientation
    To optimize performance, it is advised to install the valve on a horizontal pipe, aligning the flow direction with the arrow marked on the valve body. This ensures the valve operates according to the design and that the pressure flow is regulated correctly.

  • Valve Supports
    Support pieces should be placed near the valve to reduce the risk of structural stress, but without fastening them directly to the valve body or actuator. This separation is important to prevent vibrations or external movements from affecting the valve’s operation.

valvulas de alivio de presion autoregulables - Valfonta

Start-up of the Relief Valve

To start the operation of a relief valve, careful steps must be followed to avoid issues like water hammer, which can damage the system and the valve. Below are the basic steps for start-up:

  • Slow opening of shut-off valves
    It is recommended to open the shut-off valves gradually. This prevents sudden pressure changes that could damage the valve and other system components.

  • Pressure adjustment
    Once installed, the outlet pressure of the valve is regulated by adjusting the control screw. Turning it clockwise increases the pressure, while turning it counterclockwise decreases it. This adjustment allows the valve to be calibrated according to the system’s needs, ensuring it stays within the established safety limits.

Benefits of proper relief valve regulation

Properly regulating a relief valve not only contributes to the system’s efficiency, but also improves safety and extends the lifespan of the equipment. Here are some of the key benefits of proper regulation:

A well-regulated relief valve keeps the pressure within safe limits, preventing damage to the equipment and reducing the risk of system failures. This helps extend the lifespan of the components, minimizing wear and maintenance costs.

By maintaining the correct pressure, the system is prevented from operating at unnecessarily high levels, which reduces energy consumption. This is not only beneficial for operational efficiency but also contributes to sustainability by lowering energy expenditure.

Maintaining stable and controlled pressure is essential to ensure the safety of operators and the system as a whole. Pressure beyond the limits can lead to accidents and severe damage, so precise regulation is key to minimizing risks.

A properly adjusted relief valve allows for constant pressure control in the system, which contributes to consistency in processes and, consequently, to the quality of the final product. This is especially relevant in industries where precision is crucial for the process outcome.

These benefits make the regulation of a relief valve a fundamental practice in any system that requires precise pressure control.

Advisory and custom manufacturing at Valfonta

At Valfonta, we have over 50 years of experience in designing and custom manufacturing relief valves for all types of fluid systems. We understand that each project has unique requirements, which is why we offer personalized advice to help our customers find the relief valve that best fits their pressure, flow, and temperature needs.

Our team of experts is always ready to guide you in choosing the right relief valve, and we also offer custom solutions for cases where standard valves do not meet the system’s specific requirements. Whether for residential, industrial, or commercial applications, our relief valves are designed to deliver optimal performance and safety.

📞 Need help with your pressure relief system? Feel free to contact us for expert advice and to learn about our customized solutions. At Valfonta, we are committed to the safety and efficiency of your project.

Contact us