Safety components and systems grow increasingly flexible and scalable, and integration with other plant floor systems is edging closer to reality. "We will see the wider adoption and greater sophistication of safety controllers," predicts Tom Knauer, vp/marketing at STI, including such devices as "safety relay modules, relay-controller hybrids, safety PLCs, and specific function safety controllers." Safety devices now offer "unprecedented monitoring, preventive maintenance, and diagnosis information that is not possible without the network capability," comments Gil Guajardo, product marketing manager/safety products at Omron Electronics LLC. "They also decrease potential downtime as a result of the improved monitoring and communications capability." Safety network devices will significantly reduce the overall amount and complexity of wiring, facilitate management of the safety control information and related data, and add unprecedented flexibility to the overall control system." (For more, click here.)
What innovations can users expect in machine safety, protective technology, safety equipment and systems, and software? "A trend that is just emerging involves the design of a safety device for one specific type of machine," notes Knauer. "With this new trend, a device is machine specific, not machine independent, as is the case with moving ram optical safeguards for the hydraulic press brake, such as the STI''s LazerSafe. In the next 10-15 years, "devices will be able to act both on their own and in concert with one or more other controllers," Knauer continues. "We''ll have distributed ''intelligence'' -- a bit of processing power and memory here, some more there, perhaps a large central chunk, each responsible for managing a small part of a process, but also tied in and coordinating with other ''chunks'' of processing power." (For more, click here.)
Remote teaching technology is moving into the safety sector. Rockwell Automation safety product manager Richard Galera notes that manufacturers expect safety systems to include features available in standard controls: "A safety system that compromises productivity is unacceptable." With Rockwell''s GuardShield remote teach system, engineers cut changeover time by remotely changing a fixed-blanking configuration within the light curtain.
Guajardo points to safety PLCs, smart safety controllers with semiconductor outputs, safety controllers with logical connections, and "safety controller software that allows users to define and set various configuration parameters" as devices only available within the past year. For example, Omron''s F3SX safety controller (shown) integrates such elements as light curtains, safety doors, and emergency stop buttons through a central module. Manufacturers are parlaying recent innovations in safety system technology to "incorporate traditional safety components on an open network platform alongside traditional ''non-safety'' control devices," Guajardo adds.
Emerson Process Management''s safety solution integrates the logic solver with the diagnostics included in intelligent field devices to minimize the hazards associated with periodic manual checks of final sensing and control elements in the safety loop. The Emerson approach continuously diagnoses the sensors, logic solver, and final control elements as an entity to perform on demand as required. Emerson has integrated the operations, maintenance, and engineering environments of the Safety Instrumented System (SIS) and the basic process control system (BPCS), which ensures that the information from the intelligent field devices can be automatically routing data from intelligent field devices to the appropriate personnel in real time.
The Offshore Reliability Database shows that 42% of the failures in safety loops arise from difficulties in sensors and 50% from problems in final control elements The Emerson approach uses the intelligence in these digital devices to monitor and alert maintenance personnel and operators to possible difficulties. In addition, it is possible to replace some, or all, of the periodic manual testing of final control elements with automated partial valve stroke testing. This improves the performance of the safety loop, while reducing or eliminating the chance for human errors that occur during manual valve testing and simultaneously increasing the time between plant shutdowns. (For more, click here.)
Before a new generation of IR thermal imaging equipment became available recently, plant maintenance professionals wanting to do frequent or unscheduled electrical cabinet inspections had to choose between de-energizing circuits and forcing downtime or installing costly and fragile IR-transparent sight glasses to see just a small portion of a cabinet interior with an IR camera. Now Mikron Infrared''s combination of window-free Viewport and SpyGlass lens allows companywide standardization, allowing closed-door thermal inspections of connected electrical switchgear, while maintaining the safety barrier. A thermographer can quickly pinpoint hotspots while the circuits are energized and under load.
One example of how frequent inspections improve safety and cut costs occurred recently at a gas enrichment plant in the western U.S. The plant''s maintenance team implemented Mikron Infrared system, which identified overheated, failing connection leads to two 4,500 hp, methane compressor motors. The team corrected the problems on a controlled basis, avoiding costly unscheduled downtime and damaged equipment. A similar electrical connection problem at the plant previously caused an unscheduled outage that resulted in $1 million in lost production. (For more, click here.)