MPS = Manufacturing procedure specification

( For the following information, refer to ISO 15590-2 Petroleum and natural gas industries — Factory bends, fittings and flanges for pipeline transportation systems — Part 2: Fittings )

Fittings shall be manufactured in accordance with a documented MPS. If specified by the purchaser, manufacturing shall not proceed until the MPS has been accepted by the purchaser.

The MPS shall specify the following items (as appropriate):

a) for the starting material:

— name of manufacturer;

— steel-making process;

— steel grade;

— product form and dimensions;

— chemical composition, including that of the weld seam; — welding procedure specification.

b) for fitting manufacture:

— forming procedure;

— welding procedure specification and approval record; — heat treatment procedure including thermal cycles; — machining requirements;

— inspection and test requirements;

— traceability.

c) additional requirements such as end preparation, coating, and marking.

An approval of the MPS might be required at the beginning of production.