A fire was started in a common feed pipe.
The pipe was being used in a nitration process. The line had been used to charge 98% sulphuric acid and was then switched to 96% nitric acid. This formed a hypergolic mixture in the line which caused a fire.
- The reaction to cause the fire is well known. Obviously the line had not be HAZOPed correctly.
This is not the first incident of incompatible chemicals mixing in a common feed line. Sadly, it probably won't be the last. Items such as this should not even get past the planning stages of a plant