AdvancedTopic 91 of 100Materials & Chemical
Process safety
HAZOP, relief systems and layers of protection prevent accidents.
In depth
Safety by design: hazard identification (HAZOP, FMEA, LOPA), inherently safer design, relief systems, SIL-rated safety instrumented systems, explosion protection, fire protection and emergency response. Lessons from Bhopal, Piper Alpha, Texas City. Culture of reporting and management of change.
Key points
- Bow-tie analysis
- Layers of protection
- Dust and gas explosion limits
ExampleA HAZOP asks what happens with no flow, more flow or reverse flow at each node.
What is Process safety?
HAZOP, relief systems and layers of protection prevent accidents.
Why is it important to understand process safety?
Process safety protects workers, the public and the environment from major hazards, and it must be designed in from the start.
What is a HAZOP?
A structured review that applies guide words to process parameters to identify deviations and their consequences.
What is a layer of protection?
An independent safeguard, such as an alarm, a trip or a relief device, that reduces the chance or effect of a hazardous event.
How is Process safety used in practice?
Typical applications include carrying out a HAZOP study on a new reactor system, specifying relief valves for a vessel that could overpressure and installing trip systems and interlocks on a high-hazard unit.
What should I learn before Process safety?
Study "Process control in chemical plants" first (topic 90 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
What are the key points of Process safety?
Bow-tie analysis. Layers of protection. Dust and gas explosion limits.
Can you give an example of Process safety?
A HAZOP asks what happens with no flow, more flow or reverse flow at each node.
What comes after Process safety?
The next topic is "Process simulation", which builds directly on this one.
How difficult is Process safety?
It is classed as Advanced in Materials & Chemical (topic 91 of 100). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Materials & Chemical.