PUBLICATIONS AND VIDEOS

SUMMARY

The Interim Guidance Notes cover the subject of explosion in Section 3. Since the publication of the IGN, a greater understanding of explosions was developed. Whilst not invalidating the statements made in the IGN, this allows greater guidance to be given on the applicability of certain explosion mitigation measures. Such additional guidance is considered necessary since:

• Some mitigation measures have been confirmed not to be universally applicable (e.g., water deluge);
• Other mitigation measures require great care in design to be effective (e.g., blast relief panels);
• Measures not considered in the Interim Guidance Notes are currently being investigated and may be appropriate for certain applications.

Section 2 discusses the interface between overpressure prediction and acceptance criteria, given the uncertainties in predicting the magnitude of gas or vapour explosions and in determining the effects of mitigation measures on explosion overpressures. In practice, acceptance is tied closely to the confidence one has in the methods used to predict the overpressure.

Section 3 discusses the actions to be taken upon gas detection as a number of the explosion mitigation measures described in this document are activated on gas detection and prior to ignition.

Sections 4 and 5 consider how various mitigation systems work assuming ignition has occurred. Section 4 looks at systems that condition the atmosphere to inhibit combustion, and Section 5 looks at the performance of various blast relief systems. These sections summarise the principles of operation, outlining how the systems can be used to best effect.