Safe processes
FAQ: Safe Processes?
Ask an Expert your questions about Process Safety.
FAQ: Process
What is the future of safety technology?
If we go back in time and examine the introduction of another “disruptive technology”, Programmable Logic Controllers (PLC’s) and the impact it had on the relay market, we can learn how the introduction of safety PLC’s is shaping the future of safety technology. The PLC eliminated the complexity of electrical programming, wiring and troubleshooting found in relays and were quickly adopted in complex processes such as automotive. To expand the PLC market share, vendors had to produce more cost effective, smaller footprint PLC’s to penetrate less complex applications. While relays were still viable in less complex applications, the pressure was on to adopt the new technologies introduced by the PLC or face extinction. The innovation race was on. The PLC took a top to bottom approach and the relays a bottoms up. The intersection of these innovations, multi-function programmable relays and mid-size / micro PLC’s, became the “sweet spot” where customers benefited from competition. The same spectrum of innovation is happening today in the safety area. We are seeing the introduction of electronic, modular, programmable safety relays as well as PLC and even PC based safety controllers. This is happening at a much faster pace thanks to pace of modernization in design and manufacturing. This has allowed Siemens to quickly introduce technologies such as wireless Ethernet based safety networks in 2006. Expect to see even greater innovations in the future. Safety and standard I/O with built in wireless. A wireless mobile pad with a built-in e-stop that has intelligence to detect its location relative to different machines in a plant and allow the operator to monitor, control or even apply an E-Stop.
How could Siemens' solution help enterprise in Safety issues?
By monitoring machine downtime and production time. How often has an Estop, GateSwitch, or Lightcurtain be accuated etc. This information can be brought up to the ERP system.
The equipment mix in my facility is very diversified. In your opinion, what types of machinery and/or processes should be high priority for doing risk assessments?
As per NFPA 79, 2007 a Risk Assessment shall be conducted on all machines. You might start with any equipment that has had safety issues in the past.
How do you balance the absolute requirement of protecting your people from danger with the need to perform diagnostics and tuning while the machine is operational?
This is achieved by conducting a Risk Assesment which would incorporate all the functional aspects of the machine safety and thereby providing that balance that is necessary. And the Siemens Safety Solutions in addition provide the flexibility needed to make that a reality.
How do you monitor changes in the safety program to insure it is not changed without your knowledge?
Time and date stamp is added at every compile. Program ID Signatures are created with every program change. Safety passwords are required. The used Id is put in log file then the change is made.
How do you make something safer that you know is an issue, has had severe injury with amputations, and without comprimising the quality and necessary functions?
A complete analysis is only possible by Risk Assessment and then by looking at the applications and the safety solutions that can be implemented i.e hard guarding, optical safety etc.
Most of the safety systems information presented relates to discrete switches, but safety concepts relate to process controls also. Are there standards and devices tailored to analog parameters, such as pressure, temperature, and flow transmitters?
Yes, this would be handled by our Process Safety Group out of Springhouse PA.
http://www.automation.siemens.com/cd/process-safety
http://www.automation.siemens.com/cd/process-safety
Explain when to use Machine Safety Stds and when to use Process Safety Stds.
This is called out in the IEC 61508 standard. Machine safety is normally discrete I/O based while Process Safety normally utilizes analog I/O. Machines stop and go on a regular basis and "stopped" is consided a safe state. Processes on the other hand continue to run 24/7, if a error shuld occur they are normally "left running" at a determined safe state.