Zoned Approach Simplifies Functional Safety of Designs

[...]safety must always remain the number one priority, as a safety incident can result in damage to equipment, unforeseen costs, loss of productivity from shutdowns, and—more seriously—injury to workers, or even loss of life of life in a worst-case scenario. The use of a risk analysis prior to design Consideration of the quantitative aspects of the safety functions, as well as a qualitative approach The use of performance levels (PL) to assess the ability of safety-related parts of control systems to perform a safety function under foreseeable conditions (they are defined in terms of probability of dangerous failure per hour) According to the European Statistics on Accidents at Work (ESAW), the period between 2009—when Machinery Directive 2006/42/EC was applied—and 2013 saw non-fatal accident figures fall by 12% and the number of fatal accidents drop by 15%. The zoned safety concept allows for customized designs that are both safe and efficient. Because the safety zones can be configured to shut down compressed air and electrical power only to the group of valves that control the machine’s specific motion in the operator’s vicinity, the entire machine need not be shut down. To ensure safety, the operator must walk through a light curtain that disables the power and pilot air (only to the redundant pneumatic valves controlling the moving components in the work station), preventing unwanted motion.