Safe pneumatics

Safe pneumatic actuator technology for the output

In practice, you will be able to deal with safety issues regarding pneumatic components, for example in technical documentation or risk assessment. The applicable directive is the Machinery Directive 2006/42/EC as the basis for the functional safety of machines; the harmonized standard EN ISO 13849 is also relevant. The good news is that Festo is your competent partner in all cases. In addition to consulting, we also offer precise application notes for our solutions.

Pneumatics with Safety Service

Festo offers a wide range of individual pneumatic components, which must be evaluated in the system. In contrast to electrical systems, where you work with certified components, the functional safety of a specific application in pneumatics is usually designed and constructed using standard hardware components. The following applies here: In all cases, the machine manufacturer is responsible for safety-related evaluation and documentation.

Safety-related pneumatics are anything but trivial. This is why we provide all the relevant data for our products. What's more, our project engineers are on hand to provide you with expert advice until you have learned your way - for example, in order to go through the Failure Mode and Effects Analysis with you. With this service, you can secure your systems faster and more cost-effectively overall.

Active safety sub-functions that affect systems

SDE: Safe de-energization

The SDE function enables the directly downstream pneumatic system to be safely disconnected and de-energized.

Application note:

Safe energy-free switching with soft-start/quick exhaust valve MS6-SV -...- E (PDF)

SEZ: Safe energization

The SEZ function permits safe energization using a defined force/time function (soft-start function).

SBC: Safe brake control

The SBC function provides a safe output signal for controlling an external brake or clamping unit.

Active safety sub-functions that affect drives

STO: Safe torque off

The power supply to the pneumatic drive is disconnected. The chambers of the pneumatic drive are exhausted so that no force (torque) can be generated that could lead to a dangerous movement.

Application notes:

SSB – Safe stopping and blocking

The pneumatic drive is brought to a standstill. The free movability of the output component is blocked. Blocking can take place by means of positive locking or fictional locking.

SB – Safe blocking (not part of the VDMA 24584)

The free movability of the output component is blocked. Blocking can take place by means of positive locking or fictional locking.

Application note:

Definitions of pneumatic safety sub-functions: SB-f, PUS

SSC - Safe stopping and closing

The supply of energy to or dissipation of energy from at least one chamber of the pneumatic drive is closed, and the stored energy is used to achieve the shutdown.

Application note:

Definitions of pneumatic safety sub-functions: SSC, PUS

SET - Safe equilibrium of torque

The SET function prevents the pneumatic drive from deviating from the torque (force) equilibrium.

PUS - Prevention of unexpected start-up; lockout-tagout

The PUS function prevents the start position of the valve from changing and leading to an unexpected start-up of a machine function.

SLS - Safely limited speed

The SLS function prevents the pneumatic drive from exceeding the permissible speed.

SLT - Safely limited torque (force)

The SLT function prevents the pneumatic drive from exceeding the permissible torque (force).

SDI - Safe direction

The SDI function prevents the drive moving in the incorrect direction.

Application note:

Definitions of pneumatic safety sub-functions: SDI, PUS

SOS - Safe operating stop

The SOS function prevents the drive deviating from the stopping position by more than a defined amount. The compressed air supply is maintained to enable the drive to withstand the effect of external forces (e.g. variable load) without further measures (e.g. mechanical holding brakes).

THC - Two-hand control

Two-handed and simultaneous actuation of two control elements activates an output signal.

SS1 – Safe stop 1

The volumetric flow rates into and out of the two chambers of the pneumatic drive are reduced or blocked. This slows down the movement of the drive and brings it to a stop. If the standstill is reached in accordance with the defined tolerance window, the pressure in the chambers of the pneumatic drive is reduced so that no force (torque) is generated that could lead to a dangerous movement.

SS2 – Safe stop 2

The volumetric flow rates into and out of the two chambers of the pneumatic drive are reduced or blocked, thus slowing down the movement of the drive and bringing it to a stop. If the standstill is reached in accordance with the defined tolerance window, the pressure in the chambers of the pneumatic drive is maintained so that the existing pressure can be used to maintain the standstill.

We accompany you on your way to a safe machine in factory automation as well as to a safe system in the process industry.

How? Take a look at our guidelines on machine and system safety. Here you will not only find comprehensive information on the basic standards, risk assessment and risk reduction, but also detailed overviews of all safety functions with the appropriate products to implement these functions in your system.

The guideline also contains an overview of all Festo Training and Consulting seminars on the subject of safety engineering qualification.

Interested?

Read more in the guideline for machine and system safety (PDF)