A recent post by my colleague Michael Calaway in our Emerson internal collaboration site about a chemical safety incident resulted in a lively exchange of views, opinions and learnings on the role, use and deployment of wireless technology in process safety.
The incident in question was an unsafe condition caused by the inability to monitor the position of manually operated valves. Jonas Berge pointed that this was “yet another example of an accident occurring because manual valves are inadvertently left in a position they should not be in”. He suggested that “wireless position transmitters could perhaps help avoid some of these accidents.”
Riyaz Ali chimed in with Emerson product suggestions – the 4310/4320 wireless position transmitters – for this application and this initiated a lively interchange by Greg Kramer, Tadeu Batista,Jonas.Berge and Riyaz Ali on the various aspects of using wireless for process safety applications, egged on no doubt by my contribution of the article How to do wireless for safety systems.
The key discussions points were:
“Each individual field device shall have its own dedicated wiring to the system input/output, except in the following cases.
- Multiple discrete sensors are connected in series to a single input and the sensors all monitor the same process condition (for example, motor overloads).
- Multiple final elements are connected to a single output.”
Discussion concluded that digital communications, regardless of whether it is wired or otherwise, is not yet in the mainstream of SIS but has its place as a complementary solution to hardwired SIS prevalent on the process industry. Please add your thoughts. How are you using wired or wireless technologies to solve potential safety issues?