Hydraulic Emergency Stop

These circuits function as a hydraulic emergency shut-off; both logic elements must be open for the cylinder to move.

For additional safety, monitored valves with position indicators can be selected. We provide MTTFd values for calculating Performance Level (PL) according to EN ISO 13849-1.

How these hydraulic emergency stops work

These manifolds are designed for emergency stop. For the cylinder to move, both logic elements must be open. They are closed in the neutral state, and since they are balanced, the actual pressure in A and B has no influence on their position. The logic elements respond only to the pilot pressure from the solenoid valve in order to open. If the power supply is cut or the emergency stop is activated, the solenoid valve drains the pilot flow to the logic elements, the logic elements close, and the cylinder stops immediately.

Monitored hydraulic emergency stops

Logic elements can also be supplied in a monitored version. With these, feedback is provided in the form of an electrical signal indicating whether the valve is in the open or closed position. These are often used where personal safety is critical or where it is required by machinery or safety standards. They are common in industries such as steel plants and paper mills, where work and safety cells are used.

We can provide MTTFd values for the calculation of Performance Level (PL) according to EN ISO 13849-1.

Hydraulic emergency stop mounting and models

Above are suggestions for combinations of valve and manifold, but of course other valves with the correct cavity can also be used. The schematic symbol assumes that the hydraulic circuit diagram is drawn with the mounting plate and actuator at the bottom and the directional valve at the top of the stack.

Mounting and material of emergency stop manifolds

Several of SUN’s housings are reversible, meaning that one housing can be used for several different functions. Care must be taken to orient the housing correctly.
To assemble the stacks, threaded rods and nut sets are also required. These can be ordered in standard length or pre-cut.

All manifolds are available in aluminum (3000 psi / 210 bar) or steel (5000 psi / 350 bar), in the following sizes: NG6 (ISO/CETOP 03), NG10 (ISO/CETOP 05), NG16 (ISO/CETOP 07), and NG25 (ISO/CETOP 08). They can also be supplied with surface treatment.