This publication gives guidance on the interpretation of the Pressure Systems Safety Regulations 2000 relating to the periodic examination of pressure systems and certain associated aspects, and considers in particular Regulations 2, 7, 8, 9 and 10, plus Schedule 2; it does not refer in detail to the other regulations already clearly expounded in the British Health and Safety Executive (HSE) Approved Code of Practice, Safety of Pressure Systems (ACOP), which is freely available from the HSE. The guide should be used to augment the existing HSE documents where appropriate. This new (2009) edition revises and updates the original guide. The principal changes take account of the revised current Regulations, together with important points based upon actual use of the Regulations. Whilst EEMUA 177 refers throughout to UK regulations and practice, much of the general advice is relevant to practice outside the UK.