Safety Solved: How STO Manifolds Deliver Critical Machine Protection Without the Engineering Headaches

Bosch Rexroth Web Editorial

When hydraulic system failures mean production stops, product gets damaged, or worse—people get hurt—you need more than components. You need solutions that work right out of the box.

Your Safety Challenge Just Got Simpler

Machine builders and plant operators face a persistent problem: meeting ISO 13849 functional safety requirements for hydraulic systems often means months of engineering, custom manifold design, complex safety assessments, and expensive validation. One miscalculation, and you’re back to square one.

The Bosch Rexroth STO (Safe Torque Off) Manifold eliminates this complexity entirely.

Problem Solved: Safety Functions That Work From Day One

The STOM series delivers pre-engineered, pre-validated safety shutdowns for hydraulic systems up to Category 4 PLe—the highest safety level defined by ISO 13849. Instead of designing your own safety circuits, you select from three standardized configurations based on four simple parameters:

  • Pressure (up to 315 bar)
  • Flow rate (up to 1750 l/min)
  • Required safety level (Cat 3 or Cat 4)
  • Functions needed (STO, SDE, SLS)

Your hydraulic problems—solved. From design constraints to uptime issues, we identify root causes and deliver effective hydraulic solutions.

Three Safety Functions in One Compact Block

Safe Torque Off (STO): Two-channel, position-monitored blocking from P1 to P2 ensures leak-free shutdown of entire machine areas or systems. When it must work—you call us.

Safe Decompression (SDE): Controlled pressure relief through dual bypass valves with flow-limiting nozzles safely drains downstream pressure in under 300ms in most applications. No sudden movements. No unexpected energy release.

Safe Limited Speed (SLS): Pre-compression through the same bypass circuit minimizes switching shocks, extends component life, and reduces noise—while meeting functional safety requirements for controlled flow.

The Engineering Time You’ll Save

Traditional custom safety manifolds require:

  • 40-80 hours of safety circuit design
  • Risk assessment documentation
  • Component selection and validation
  • Safety logic programming
  • Final system validation

With STOM, you select a material number from a datasheet. Documentation, validation calculations, and installation instructions are included. Every solution is engineered to simplify your machine lifecycle: Design → Installation → Operation → Maintenance.

Real-World Reliability From Decades of Expertise

The STOM portfolio builds on proven Bosch Rexroth valve technology—pilot-operated check valves (SL) in sizes 20/30, and actively controllable 2-way cartridge valves (LC2A) in sizes 32/40. These aren’t experimental components. They’re field-tested workhorses now configured for functional safety.

Galvanized surface coating provides long-term corrosion protection. Compatibility with mineral oils (HLP) and flame-resistant fluids (HFC, HFDU) means retrofit flexibility. Identical electrical control across all nominal sizes simplifies commissioning and spare parts management.

Stop Paying an Electrician to Wire Your Hydraulic Valves

Bosch Rexroth STO (Safe Torque Off) Manifold 

When Performance Bottlenecks Impact Output

Heavy-duty presses, metallurgical plants, and test benches face a common challenge: hydraulic area shutdowns that meet safety standards while minimizing production disruption.

A metal forming facility recently integrated STOM-32B4E manifolds for zone isolation. Results:

  • 87% reduction in safety engineering time versus custom design
  • Closing times under 280ms with 200-bar system pressure
  • Safe decompression in 1.2 seconds for 12-liter downstream volume
  • Zero safety-related downtime in first 18 months of operation

When performance bottlenecks impact your output, our specialists solve them with data-driven, high-performance hydraulics.

Your Challenges Just Became Manageable

Whether you face unpredictable downtimes during retrofits, need breakthrough safety compliance for new machine designs, or require reliable area shutdown for high-risk operations—STOM manifolds make your challenges manageable.

We’re not just a hydraulics supplier. We are the problem solvers behind your productivity—reducing downtime, simplifying design, streamlining installation, and optimizing performance.

CMA/Flodyne/Hydradyne is an authorized Bosch Rexroth distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

Leave a comment