When we maintain hazardous plant and equipment we need to make sure it is safe to open up, breaking the pressure envenlope. Process isolation is a very critical activity, but practices do not always achieve what they appear to.
LPB 2013 – Process isolations – more complicated that you think
LPB 2016 Double block & bleed – more complicated than you think
TCE 2019 Degrees of separation
Reinstatement after maintenance is another activity that has not always received the attention is should. Guidance is now encouraging more use of full pressure leak testing with inert fluids (typically nitrogen) but this can be a very hazardous activity.
2023 Hazards 33 – Leak testing reinstatement – More complicated than you think
Managing the risks of stored energy – always expect the unexpected.