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Changes in the type and structure of valves
Valve type and structure from the 23rd edition of the text moved to the new version of the Appendix B "valve structure"; 23rd edition of the structure of the length of Table 6 moved to the new version of the Appendix C "Valve end-to-end, face-to-face dimensions of Table C". Table 1 in the standard, "the minimum diameter of the channel of the full diameter valve" in the deletion of the expression PN, using "Classxxx" to indicate the pressure level. Accordingly, the word "PN" can no longer appear on any occasion, including nameplates, for API 6D valves in the future. New: If there is no minimum internal part size for the pressure class and size of valves listed in Table 1, the size and internal diameter shall be determined by agreement and identified on the nameplate.
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Changes in design and calculation
Pressure-bearing components design and calculation refer to internationally recognized standards;
Add EN12516-2 industrial valves - shell stress calculation Part II calculation method;
1, the addition of ASME Boiler Pressure Vessel Volume II Materials, Part D: Mechanical Properties, as the basis for the design using ANMEVIII code;
2, Pressure-TemperatureRatings (Pressure-TemperatureRatings) in the deletion of the expression about PN, pointing out that: all metal pressure-bearing parts and pressure control components should be in accordance with the "valve pressure-temperature ratings" design;
3, the size of the expression: first write the nominal pipe size (NPS), and then write the equivalent nominal size (DN) in parentheses, for example:
Full bore valve: NPS12 (DN300)
Reduction valve: NPS12 (DN300) X NPS10 (DN250)
4, add a chart - "flange standard size" to illustrate the convex flange, ring joint groove flange on the size, tolerance, shape tolerance, surface roughness and other requirements;
5, the design of the drive device selection, installation should be in line with the requirements of API 6DX or ISO 12490; this is a new requirement; the maximum diameter of the handwheel does not exceed 1065mm;
6, the valve manufacturer shall verify the applicability of the location of the lugs on the finished valves and operating devices, as well as the specialized design, manufacture and certification of the lug device;
7, permit force in the API6D 2nd 4 edition of the 2004 ASMEVIII-2, AD132 expression in the text. And the ASME BPVC Volume II, Part D section on compressive stresses is also included in the standard. Tensile stresses, shear stresses (including torsional shear stresses), and compressive stresses shall be designed in accordance with ASME BPVC Volume 8, except that the design stress intensity value Sm is greater than 67% of the minimum yield strength (SMYS). In addition, for pure shear stresses (e.g., shawls, shear rings, threads) the average shear stress shall be limited to 0.8 Sm. (Note: The standard indicates stress intensity Sm, not stress.) Permissible stress under pressure: see ASME BPVC IID section.
8. Structural Length (F-F or E-E):
The structure length of the old version of Table 2 ~ 6 moved to the new version of Appendix C.1 ~ C.5 "Valve end-to-end, face-to-face dimensions Table C"
Structure length dimension ≤ NPS10 (DN250) tolerance is plus or minus 1.5mm, old version is plus or minus 2.0mm
If the valve with support foot exceeds the structure length, then the support foot should be removable after installation.
9, valve operation: new valve in the operation of the thrust or torque