Pilot Controlled Series

A pilot-operated safety valve is an automatic pressure safety device consisting of a main valve and an auxiliary pilot valve that controls its movement. When the system pressure remains within the normal operating range, pressure is directed to the upper section of the main valve to generate a closing force. This keeps the main valve firmly seated and prevents the process fluid from entering the discharge line.

When the system pressure reaches the predetermined set pressure, the pilot mechanism is activated. The pilot valve reduces the control pressure above the main valve, allowing the main piston or diaphragm to move. The main valve then opens, and the excess fluid is discharged in a controlled manner. Once the pressure falls to a safe level, the pilot mechanism closes again, the control pressure is restored, and the main valve returns to its sealed position.

Thanks to this operating principle, a pilot operated safety valve can maintain stable shut-off performance even when the normal system operating pressure approaches the set pressure. However, for reliable valve operation, the pilot lines, control passages, and related components must be designed in accordance with the process conditions.

The operating principle of a safety relief valve is generally based on the balance between system pressure and the spring force inside the valve. When the inlet pressure exceeds the set opening pressure, the valve disc lifts from its seat and the discharge process begins. This automatic mechanism helps protect equipment against overpressure without requiring operator intervention.

Pilot-operated safety valves can be used in a wide range of industrial applications involving high pressure, high capacity, or variable operating conditions. Oil and natural gas facilities, refineries, petrochemical plants, power plants, chemical production lines, and gas storage systems are among their most common application areas.

Pilot operated safety valve solutions can be used in pressure vessels, pipelines, compressor systems, process vessels, and high-capacity gas lines. Pilot-operated designs can provide significant advantages, particularly in systems operating close to the set pressure and requiring high sealing performance. Products with an appropriate design may also be selected for applications involving variable back pressure.

However, the contamination level, viscosity, and chemical properties of the process fluid must be carefully evaluated during the selection process. Depending on the process conditions, filtration or special design measures may be necessary to prevent particles from affecting the narrow control passages within the pilot mechanism. Kiatork provides technical support by reviewing application data and determining whether the valve is suitable for the relevant process.

Working with a technically competent safety valve supplier is essential for obtaining products that meet specific operational requirements. The supplier should evaluate not only product specifications but also the process fluid, temperature, pressure values, and facility conditions. Kiatork examines application data in detail and provides solutions designed to support system safety and operational efficiency.

One of the primary advantages of a pilot-operated safety valve is its ability to maintain high sealing performance as the system pressure approaches the set pressure. In many designs, the force keeping the main valve closed increases together with the system pressure. This feature helps reduce the risk of leakage in processes where the difference between the normal operating pressure and set pressure is limited.

When selected correctly, a pilot operated safety valve can offer an effective solution for controlling high discharge capacities. As the main valve is controlled by the pilot mechanism, its opening and closing behavior can be configured according to the process requirements. Some designs provide rapid opening characteristics, while others can relieve pressure in a modulating manner.

Models equipped with a suitable pilot design can deliver reliable performance under variable back pressure conditions. In large-scale applications, reducing the need to control the main valve directly with a mechanical spring can also contribute to the development of more compact and efficient solutions. To benefit from these advantages, the product must be correctly selected and sized according to the specific process conditions.

In every safety valve application, the type of discharged fluid, required discharge capacity, and back-pressure conditions must be considered. Opening at the set pressure alone is not sufficient; the valve must also be capable of relieving excess pressure at the required capacity and within the appropriate period. Kiatork evaluates these technical parameters comprehensively to develop reliable product solutions.