What must be taken into consideration when designing pneumatically operated separating guards?
Guards must be designed in accordance with EN 953:1997. Guards are classified as fixed or movable. The following is set out in EN 953:1997 regarding powered guards: “Powered guards must not cause injuries (e.g. due to closing pressure, exerted force, speed or sharp edges). If the guard is fitted with another safety device which automatically re-opens the guard as soon as the guard comes in contact with a person or object, the force to prevent the guard closing must not exceed 150 N. The kinetic energy of the guard must not exceed 10 Nm. If no such safety device is fitted, these values must be reduced accordingly to 75 N and 4 Nm, respectively.” Simple pneumatically driven, horizontally or vertically closing doors or windows must therefore be designed with values of 75 N and 4 Nm. The higher values can only be applied if the doors or windows are functionally linked to e.g. safety mats, light barriers, touch-sensitive barrier rails etc. which automatically cause the guard to re-open.
