This part of ISO 10465 describes the procedures for underground installation of flexible glass-reinforced thermosetting resin (GRP) pipes. It refers generally to GRP pipes as specified in the system standards ISO 10467 and ISO 10639, but it can also be used as a guide for the installation of other GRP pipes. It does not include jacking, relining or above-ground installations; nor does it cover health and safety or environmental conditions, these being addressed in national regulations at the place of installation.