This Defence Standard (DEF STAN) describes the minimum procedures and/or processes to be applied to all compressed air systems and their component parts during manufacture, overhaul, cleaning, purging, and testing to ensure that the required high standards of cleanliness of the air at various terminal points/joints meet those specified in Table 5.1.

This Standard applies to both HM Surface Ship and Submarine, compressed air systems from the purification equipment provided at the source of supply up to the point of supply to the user. It does not cover cleanliness standards for the end user equipments, which will be specified separately to meet the minimum standard relevant to that system.

This Standard does not override any special cleanliness requirements applicable to the Nuclear Submarine Systems laid down in the relevant System Requirement Document (SRD).