Redundant safe

Pneumatically controlled systems must be vented quickly in the event of an emergency stop to avoid posing a hazard. This often involves multiple components, which also waste valuable time until complete venting. SMC has therefore developed the VPX400 series safety exhaust valve, which combines three functions in one device: rapid exhaust, valve condition monitoring, and compressed air supply control.

It complies with ISO 13849-1 categories 3 or 4, is doubly redundant, and features a soft-start function. The series can also be combined with SMC's AC-D series modular maintenance units, has an IP65 protection rating, and enables direct status monitoring thanks to LEDs.

Functional safety is paramount in any system – especially when it comes to protecting people. In the event of an emergency stop, it is important to ensure that pneumatic systems in the automotive, robotics, packaging, and food industries, for example, are vented as quickly as possible. With the new VPX400 series, SMC has developed a multifunctional single solution for this purpose. The safety exhaust valve provides a uniquely fast exhaust on the market, monitoring two internal valves to ensure double redundancy.

The already certified product thus meets the highest performance requirements of ISO 13849-1 and can be used in parallel to control the compressed air supply, enabling a soft-start function. It is also equipped with LEDs for immediate status monitoring, can be combined with SMC's modular maintenance units, and is also impressively robust thanks to its IP65 protection rating.

Three functions in one device

With exhaust characteristics from 10,500 to 15,000 l/min (ANR), the VPX400 series safety exhaust valve particularly quickly reduces the risk of residual compressed air in the event of an emergency stop scenario. This is achieved thanks to a large effective cross-section for ports 2 and 3, which leads to rapid pressure reduction. A special silencer from the INA-25-100 series not only ensures low noise levels but also ensures that exhaust is not restricted.

The mutual monitoring of the two integrated valves provides double redundancy, which meets the requirements of ISO 13849-1 in categories 3 or 4. SMC's already certified solution also features an integrated soft-start function. This allows users to precisely limit the flow of air supplied by the valve to prevent sudden movements in pneumatic systems.

In addition, the new safety exhaust valve can be directly integrated into SMC's AC-D series modular maintenance units, for example, with a filter, pressure regulator, and flow meter – and forms a visually appealing unit thanks to the same design. If the VPX400 series is equipped with either a pressure gauge or a digital pressure sensor, the machine pressure can be read directly on the valve. Overall, users benefit from three functions in a single product with the highest level of safety, while reducing space, installation, and maintenance effort.

Frugal, clear, and robust

The VPX400 series is a compact, lightweight device: In a direct comparison between its predecessor, the VP746 series, and the VPX406-A4 variant, the size has been reduced by 60% and the weight by 9%. At the same time, the internal valves, with a consumption of only 0.2 watts each when active, reduce energy consumption and thus ensure negligible waste heat. The CO2 footprint also benefits. The power connection is made via two M12 connectors.

The VPX400 series monitoring system independently detects errors and displays them via four status LEDs located directly at the connector input. This simplifies and speeds up troubleshooting on a stationary machine, reducing expensive downtime. Available in three sizes and suitable for an operating pressure range of 0.25 to 1.0 MPa, the solution also meets IP65 protection class. This means it is protected from water and dust and can therefore perform its duties without any problems even in harsh environments.