Built for Power Loss: How KEB Brakes Support Fail-Safe Actuators

Power failures don’t have to mean loss of control. Learn how Schiebel’s fail-safe actuators and KEB’s Power-on brakes work together to ensure valves move to a safe position when it matters most.

Prepared for Every Scenario

In pipeline applications, where the consistent flow of materials is an essential process, an unexpected power loss can interrupt material flow, halt production, and create safety risks if critical valves cannot respond.

That’s why an emergency operation plan is designed into the system from the beginning.

Valves regulating oil, gas, and water pipelines must immediately transition to a designated safe position during an emergency. Whether that means closing a valve to isolate a hazard or opening one to maintain critical flow, the actuator must respond instantaneously, even during a complete loss of electrical power.

Meeting these extreme performance requirements is where Schiebel Antriebstechnik excels. Based in Austria, Schiebel has spent over 60 years engineering and manufacturing high-reliability electric actuators. That deep application expertise makes them a trusted partner across water treatment facilities, power plants, and oil and gas networks worldwide.

The Importance of Fail-Safe Valve Operation

One of Schiebel’s key actuator offerings is its fail-safe series, designed for applications where valves must automatically move to a predetermined spot in the event of a power failure.

Traditionally, electric actuators rely heavily on electrical power to position a valve. If power is interrupted, the actuator typically stops in whatever area it’s at. In pipeline applications, this can interrupt material flow or prevent a valve from reaching the position needed to protect the system.

Schiebel addresses this challenge with its fail-safe series, which combines an electric actuator with a mechanical spring-return system. During normal operation, the actuator positions the valve as needed and stores mechanical energy within the spring mechanism. In the event that power is lost, that stored energy is immediately released, automatically moving the valve to its safe position.

Depending on the application, this safety position may be fully open, closed, or another agreed upon position that will protect the equipment and the process itself. Because the system relies on the stored mechanical energy rather than backup power, it can respond even during a complete electrical failure.

“The advantage of our fail-safe series is that in the event of a power failure, valves can be moved to a predefined position in less than a second – and with maximum precision,” says Klaus Schiebel, CEO of the Viennese family business.

The Power-On Brake Driving Schiebel’s Actuator

While the spring mechanism provides the stored mechanical energy during a power failure, it also doubles as a dependable holding machine. To ensure that energy remains available until it’s needed, the actuator relies on a brake to hold and secure the spring-loaded system in place. When electrical power is interrupted, the brake releases, allowing the actuator to move the valve to its determined safe position.

When selecting a brake that could match the precision and engineering rigor of their own actuator design, Schiebel turned to KEB’s COMBINORM B Power-on brake to manage the actuator’s holding and release cycle.

“We use the brake in sizes 6 to 9 to keep the integrated spring-return mechanism in place with a sufficient power supply,” said Robert Kwich, Sales Area Manager East at KEB Austria.

Available in a variety of sizes, KEB’s COMBINORM Power-on brake provides the dependable holding force required for Schiebel’s fail-safe actuators. This anti-remanence, power-on brake is designed for 100% duty cycle and continuous operation without sacrificing performance. Its short switching times and consistent positioning accuracy ensure the actuator responds as quickly and consistently as possible during emergencies, while its wide range of voltage options allow it to easily integrate into actuator configurations.

The power-on brake is also engineered to operate across a wide range of temperature and voltage ranges. Schiebel’s actuators are placed in various applications including natural gas fields in northern Canada, where temperatures can drop to as low as -50°C and industrial facilities operating at +50°C.

“Our customers expect the highest quality and reliability,” says Schiebel. Regardless of the environment, KEB’s Power-on brake delivers reliable holding performance and supports the fail-safe operation of Schiebel’s actuators.

A Fail-Safe Partnership

Over more than 15 years of collaboration, Scheibel and KEB have refined the integration between the power-on brake and fail-safe series actuators to ensure reliable, efficient operation in the field.

Beyond the engineering specs, however, the foundation of this success rests on the close relationship between KEB Austria and Schiebel.

“A good product isn’t everything, it’s about the overall package. We appreciate the reliable service and have a direct contact person for any concerns. And since our Fail-safe series is a customized product, the technical advice and experience from KEB was also very helpful,” says Schiebel.

Robert Kwich adds, “We place great importance on remaining in close contact with our customers even after commissioning and offering the best possible support. Schiebel and KEB are very similar in this quality mindset.”

Keeping Pipeline Systems Moving Safely

In critical pipeline operations, safety depends on every single component doing its job without fail. By integrating KEB’s anti-remanence Power-on brakes with Schiebel’s spring-return actuators, these systems achieve sub-second valve shutoffs during complete power loss. The result? Pipeline operators get a fast, reliable, fail-safe defense against catastrophic failures when every millisecond counts.

If you’re interested in reading more about KEB’s role within Schiebel’s actuators, be sure to check out Fail-Safe actuators: With KEB brakes in the Pipeline. For more information on KEB’s brakes and other products, explore www.kebamerica.com.