2. General principles for the installation of flammable gas detectors

2.1 Defining the layout

The need to design a fixed flammable gas detection system can have several origins. Firstly, quantified risk analyses (of the HAZID, HAZOP, bow-tie, etc. type) may highlight scenarios involving loss of containment of flammable products, requiring the implementation of risk control measures (e.g. gas detection system). Local authorities may also require the installation of a detection system. These requirements may differ according to the type of installation and its location. They may require the installation of a risk control system, or be more prescriptive, defining the means to be implemented in terms of detection. The operator may also have internal standards in place, which provide for the design of a detection system and specify the rules to be followed....