API SPEC 6DSS-2009 pdf free download

API SPEC 6DSS-2009 pdf free download.Specification for Subsea Pipeline Valves.
1 Scope This International Standard specifies requirements and gives recommendations for the design, manufacturing, testing and documentation of ball, check, gate and plug valves for subsea application in offshore pipeline systems meeting the requirements of ISO 13623 for the petroleum and natural gas industries. This International Standard is not applicable to valves for pressure ratings exceeding PN 420 (Class 2500). 2 Conformance 2.1 Rounding Except as otherwise required by this International Standard, to determine conformance with the specified requirements, observed or calculated values shall be rounded to the nearest unit in the last right-hand place of figures used in expressing the limiting value, in accordance with the rounding method of ISO 31-0:1992, Annex B, Rule A. 2.2 Compliance to standard A quality system should be applied to assist compliance with the requirements of this International Standard. NOTE ISO/TS 29001 gives sector-specific guidance on quality management systems. The manufacturer shall be responsible for complying with all of the applicable requirements of this International Standard. It shall be permissible for the purchaser to make any investigation necessary in order to be assured of compliance by the manufacturer and to reject any material that does not comply. 3 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 7-1, Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances and designation ISO 31-0:1992, Quantities and Units — Part 0: General Principles ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions, tolerances and designation
4.15 maximum pressure differential MPD maximum difference between the upstream and downstream pressure across the obturator at which the obturator may be operated [ISO 14313:2007, 4.15] 4.16 nominal pipe size NPS numerical imperial designation of size, which is common to components in piping systems of any one size NOTE Nominal pipe size is designated by the abbreviation “NPS” followed by a number. [ISO 14313:2007, 4.16] 4.17 nominal pressure class PN numerical pressure design class used for reference purposes NOTE Nominal pressure class is designated by the abbreviation “PN” followed by a number. [ISO 14313:2007, 4.17] 4.18 nominal size DN numerical metric designation of size that is common to components in piping systems of any one size NOTE Nominal size is designated by the abbreviation “DN” followed by a number. [ISO 14313:2007, 4.18] 4.19 obturator closure member part of a valve, such as a ball, clapper, disc, gate or plug that is positioned in the flow stream to permit or prevent flow [ISO 14313:2007, 4.19] 4.20 operator device (or assembly) for opening or closing a valve [ISO 14313:2007, 4.20] 4.21 packing gland component used to compress the stem packing [ISO 14313:2007, 4.21] 4.22 piggability capability of a valve to permit the unrestricted passage of a pig [ISO 14313:2007, 4.23]
6 Valve types and configurations 6.1 Valve types 6.1.1 Gate valves Typical configurations for gate valves with flanged and welding ends are shown, for illustration purposes only, in Figures 1 and 2. Gate valves shall have an obturator that moves in a plane perpendicular to the direction of flow. 6.1.2 Plug valves Typical configurations for plug valves with flanged and welding ends are shown, for illustration purposes only, in Figure 3. Plug valves shall have a cylindrical or conical obturator that rotates about an axis perpendicular to the direction of flow. 6.1.3 Ball valves Typical configurations for ball valves with flanged or welding ends are shown, for illustration purposes only, in Figures 4, 5 and 6. Ball valves shall have a spherical obturator that rotates on an axis perpendicular to the direction of flow.