Springs for industrial valves are critical components for the correct operation of valves, actuators and safety devices. They must ensure consistent performance even under high pressure, fluctuating temperatures, vibration and repeated operating cycles.
Spring selection depends on the operating conditions of the application and involves several factors, including material, geometry, spring characteristics and heat or surface treatments.
The function of springs in actuators and valves
- Actuator springs help open, close and return the valve to its designated position.
- In pneumatic actuators, springs return the valve to its fail-safe position if pressure is lost.
- In safety valves, the spring applies a calibrated force to keep the valve disc or obturator in position until the set pressure is reached.
- In control valves, springs contribute to controlling the movement of the valve plug in response to the actuation system.
Types of springs for valves and actuators
Spring configuration depends on the type of valve or actuator, the available space and the required load.
Industrial valve springs are generally manufactured as helical compression springs, although other geometries may be used depending on the application.
Compression springs are among the most widely used solutions for valves and actuation systems. In applications where installation space is limited, disc springs (Belleville springs) may also be used, as they can provide high forces within a reduced axial space.
Spring geometry is defined according to dimensions, loads and operating conditions, taking into account stress levels, deflection, cycle frequency and temperature.
Applications in the energy, Oil & Gas and process industries
Industrial valve springs are widely used in refineries and Oil & Gas facilities for the control of oil, gas and process fluids; in the energy sector, for example in systems handling steam, water and thermal fluids; and in chemical, petrochemical and process plants.
In these environments, springs may be exposed to high operating cycles, fluctuating temperatures and harsh environmental conditions, making reliability and long-term performance stability essential.
Materials
A range of materials and wire grades are used to manufacture springs for industrial applications. These include CrSi and CrV alloyed pre-tempered spring wires, compliant with EN 10270-2, which are suitable for applications requiring high performance and good fatigue resistance.
For applications requiring increased resistance to corrosive environments, stainless steel spring wires compliant with EN 10270-3 are available.
For particularly demanding operating conditions, nickel-based alloys can also be used, including Inconel 750, Inconel 718, Nimonic 90 and Hastelloy. These materials are valued for their ability to maintain good mechanical properties and dimensional stability at elevated temperatures and under particularly severe operating conditions.
The most suitable material grade must be selected based on the actual operating conditions to which the spring will be exposed.
Shot peening, presetting and quality control
Specific treatments and manufacturing processes can be used to improve the performance of springs subjected to repeated operating cycles.
Shot peening is a cold mechanical treatment in which the spring surface is bombarded with a high-velocity stream of spherical media. This process significantly increases spring fatigue life under repeated cyclic loads by reducing the risk of premature fatigue failure and improving the component’s overall service life.
Presetting, or spring scragging, consists of subjecting the spring to a controlled compression load up to a condition defined during the design phase. The process stabilizes the spring geometry and elastic characteristics, reducing dimensional changes during the initial operating cycles.
The manufacturing process is completed by dimensional inspections, verification of spring load characteristics, material testing and, where required by the specific application, non-destructive testing (NDT).
Industry certifications and standards
Documentation requirements depend on the industry sector, equipment, application and customer specifications. For valves and pressure equipment intended for the European market, the Pressure Equipment Directive (PED) 2014/68/EU may apply. The directive covers the design, manufacture and conformity assessment of pressure equipment.
In the Oil & Gas sector, specific API standards are also used for valves and overpressure protection devices. These include API 520, which covers the sizing and selection of pressure-relief devices, and API 526, which specifies flanged steel pressure-relief valves.
For the spring manufacturer, these requirements may involve ensuring raw material traceability, material certificates, dimensional and functional inspections, and documentation of the tests performed, in accordance with the applicable technical specification.
Springs Group: springs for industrial actuators and valves
Springs Group manufactures custom-designed springs for industrial actuators and valves, produced according to the specific requirements of each application. Our product range includes compression, extension, torsion and disc springs, manufactured from steels and special alloys.
From material selection through manufacturing and final inspection, Springs Group supports customers in developing springs for valves, actuators and control systems used in industrial applications.