This document provides a set of common supplementary requirements for the most frequently used materials in upstream oil and gas piping systems. This document is applicable to offshore and onshore production facilities, processing and gas liquefaction plants. The materials covered in this document are intended to be used in the following piping systems services: –     category D, category M, normal and high pressure, according to ASME B31.3; –     sour environments as defined in the ISO 15156 series. NOTE            For the purposes of this document, ANSI/NACE MR0175 is equivalent to the ISO 15156 series, and ANSI/NACE MR0103 is equivalent to ISO 17945. This document does not provide guidelines for material selection. The selection of suitable materials for a specific service including any necessary additional material requirements remains the responsibility of the end user. This document does not cover requirements related to: –     sulfide stress cracking (SSC) in corrosive petroleum refining environments included in ISO 17945; –     non-metallic piping systems according to ASME B31.3 or the ISO 14692 series; –     marine piping systems, e.g. ballasting piping system, covered by classification rules; –     subsea production systems; –     downhole equipment; –     transportation pipeline systems, including flowlines, designed in accordance with a recognized pipeline design code. Common requirements related to manufacture, inspection and procurement of piping and valve parts are included in Annex A and Annex B, providing material datasheets and element datasheets, respectively. These material and element datasheets can be applied for applications other than piping systems, e.g. pressure vessels and pumps based upon assessment of the end user and conformance with the selected design code for the relevant equipment. This document is not intended to limit the use of alternative materials or grades within a referenced material standard. Where the use of alternative materials/grades are considered appropriate, the end user is responsible for specifying any additional requirements necessary to meet the design code or specification.