API SPEC 6D-2009 pdf download.Specification for Pipeline Valves.
1 Scope This International Standard specifies requirements and provides recommendations for the design, manufacturing, testing and documentation of ball, check, gate and plug valves for application in pipeline systems meeting the requirements of ISO 13623 for the petroleum and natural gas industries. This International Standard is not applicable to subsea pipeline valves, as they are covered by a separate International Standard (ISO 14723). This International Standard is not applicable to valves for pressure ratings exceeding PN 420 (Class 2 500). 2 Conformance 2.1 Units of measurement In this International Standard, data are expressed in both SI units and USC units. For a specific order item, unless otherwise stated, only one system of units shall be used, without combining data expressed in the other system. For data expressed in SI units, a comma is used as the decimal separator and a space is used as the thousands separator. For data expressed in USC units, a dot (on the line) is used as the decimal separator and a comma is used as the thousands separator. 2.2 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. 2.3 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.
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, corrigendum, and maintenance agency output) applies. 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 ISO 5208:1993, Industrial valves — Pressure testing of valves ISO 7268, Pipe components — Definition of nominal pressure ISO 9606-1, Approval testing of welders — Fusion welding — Part 1: Steels ISO 9712, Non-destructive testing — Qualification and certification of personnel ISO 10474, Steel and steel products — Inspection documents ISO 10497, Testing of valves — Fire type-testing requirements ISO 15156 (all parts), Petroleum and natural gas industries — Materials for use in H 2 S-containing environments in oil and gas production ISO 15607, Specification and qualification of welding procedures for metallic materials — General rules ISO 15609 (all parts), Specification and qualification of welding procedures for metallic materials — Welding procedure specification ISO 15614-1, Specification and qualification of welding procedures for metallic materials — Welding procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys ISO 23277, Non-destructive testing of welds — Penetrant testing of welds — Acceptance levels
4 Terms and definitions For the purposes of this document, the following terms and definitions apply. 4.1 ASME rating class numerical pressure design class defined in ASME B16.34 and used for reference purposes NOTE The ASME rating class is designated by the word “class” followed by a number. 4.2 bi-directional valve valve designed for blocking the fluid in both downstream and upstream directions 4.3 bleed drain or vent 4.4 block valve gate, plug or ball valve that blocks flow into the downstream conduit when in the closed position NOTE Valves are either single- or double-seated, bi-directional or uni-directional. 4.5 breakaway thrust breakaway torque maximum thrust or torque required to operate a valve at maximum pressure differential 4.6 by agreement agreed between manufacturer and purchaser 4.7 double-block-and-bleed valve DBB single valve with two seating surfaces that, in the closed position, provides a seal against pressure from both ends of the valve with a means of venting/bleeding the cavity between the seating surfaces NOTE This valve does not provide positive double isolation when only one side is under pressure. See double- isolation-and-bleed valve (4.8).