On a subsea facility, the subsea pipeline normally terminates at the connection to a christmas tree or wing valve. The christmas tree is not considered part of the pipeline system. On a subsea facility where the above definition cannot be applied, the subsea pipeline ends at the connection to the subsea facility. The connection piece is part of the subsea pipeline. Subsea pipelines and risers up to and including the chamber for launching or receiving tools for internal maintenance (including inspection), with associated equipment, are considered to belong to the pipeline system. If such a chamber has not been installed, the pipeline system is considered to extend to the first automatic shutdown valve above water.
Source: Guidelines Regarding the Facilities Regulations, Norway, updated December 2012. Regulatory Guidance