Specification 17D provides specifications for subsea wellheads, mudline wellheads, drill-through mudline wellheads and both vertical and horizontal subsea trees. It specifies the associated tooling necessary to handle, test and install the equipment. It also specifies the areas of design, material, welding, quality control (including factory acceptance testing), marking, storing and shipping for both individual sub-assemblies (used to build complete subsea tree assemblies) and complete subsea tree assemblies.

The user is responsible for ensuring subsea equipment meets any additional requirements of governmental regulations for the country in which it is installed. This is outside the scope of this Specification.

Where applicable, this Specification can also be used for equipment on satellite, cluster arrangements and multiple well template applications.

Specification 17D includes equipment definitions, an explanation of equipment use and function, an explanation of service conditions and product specification levels, and a description of critical components, i.e. those parts having requirements specified in this Specification.

This document is not applicable to the rework and repair of used equipment.

This edition of ANSI/API Specification 17D is the identical national adoption of ISO 13628-4, Design and operation of subsea production systems-Part 4: Subsea wellhead and tree equipment.