Going Beyond HAZOP
Knowing what comes after HAZOP can be difficult. Let us help by explaining the next key stages in the Hazard Study Process. Hazard Study terminology can differ in organisations, but following our Hazard Study 1, HAZID and HAZOP process there are further Hazard Studies you may want to consider following HAZOP. These are Hazard Studies HS4 HS5 and HS6
Hazard Study 4 – HS4
Hazard study 4 is completed at project handover to commissioning. The aim of the Hazard Study 4 is to ensure that the plant has been installed correctly.
These checks involve P&ID checks against the plant to ensure that equipment has been installed in the correct locations and orientation (for example non return valves facing the correct way), that joints have been fully tightened and that pipework is properly supported. The physical layout of the plant is also checked – for any issues which might have arisen during construction such as making sure that valve handles are accessible and escape routes have not been blocked.
Hazard Study 5 – HS5
Hazard Study 5 is completed after water trials, but before any the process chemicals are introduced into the system. HS5 is usually a checklist-based approach. It ensures that actions from the earlier hazard studies have been completed and that any issues found during Hazard Study 4 and commissioning trials have been addressed. This ensures that the plant is ready for use with chemicals.
Hazard Study 6 – HS6
Once the process has been up and running for a time period, the plant operation is evaluated to make sure everything is operating as intended.
This should identify any gaps between design and operation. This could include: if safety trips are being called upon more frequently than the designers expected; any near misses or incidents which may have occurred; or activation of any relief devices. Hazard Study 6 might also consider any management of changes/ plant modifications that have been carried out. All of these instances may identify something that needs rectified or aspects of the design reassessed.
Timings for Hazard Studies HS4 HS5 and HS6
Hazard Study 4 and 5 should always be carried out as part of commissioning of the plant. The timing of Hazard Study 6 can vary, to ensure it is done at a time when enough operating experience is gained, but before the list of issues may have become too long to rectify. Typically this could be 6 to 12 months after commissioning.
If you need assistance with knowing what studies would be required for your process, we are here to help and provide guidance.