I thought I might start a serious of posts on location classification, since it’s an important concept in AS 2885 and some aspects of it cause confusion.
To start with the basics, location classification is a way of categorising land uses to reflect the threats to and from the pipeline. Where there are lots of people there is not only likely to be an increased level of activity that might result in pipeline damage, but the consequences of a serious pipeline failure will probably also be greater. So in more populated areas we need more stringent protection against pipeline failure.
The primary purpose of the AS 2885 location classes is to draw attention to the greater risk level in more populated areas so that the pipeline can be designed (or managed) appropriately. The standard doesn’t actually have many fixed rules that vary between location classes. The most important set of rules are in Section 4.7, Special Provisions for High Consequence Areas. Apart from that it has some fairly common-sense requirements for things like depth of cover and sign spacing, although even those often make little distinction between R1 and R2, or between T1 and T2.
My view is that the most important function of location classification is to help focus the safety management study on the areas where the likelihood and/or consequences of a failure may be greatest. For that reason I don’t care much about getting the location classification exactly right. As long as the chosen classification will guide you to an appropriate design (or risk management measures) then it doesn’t matter whether you’ve adopted, say, R2/I or T1 for an industrial area.
Over the next few posts I hope to work my way through each of the primary and secondary location classes with some guidance material and observations on pitfalls.