IEC 60534-2-3 pdf download

IEC 60534-2-3 pdf download.Industrial-process control valves – Part 2-3: Flow capacity – Test procedures
1 Scope
This part of IEC 60534 is applicable to industrial-process control valves and provides the flow capacity test procedures for determining the following variables used in the equations given in IEC 60534-2-1: a) flow coefficient C; b) liquid pressure recovery factor without attached fittings F L ; c) combined liquid pressure recovery factor and piping geometry factor of a control valve with attached fittings F LP ; d) piping geometry factor F P ; e) pressure differential ratio factors x T and x TP ; f) valve style modifier F d ; g) Reynolds number factor F R .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60534-1 , Industrial-process control valves – Part 1: Control valve terminology and general considerations IEC 60534-2-1:2011, Industrial-process control valves – Part 2-1: Flow capacity – Sizing equations for fluid flow under installed conditions IEC 60534-8-2, Industrial-process control valves – Part 8-2: Noise considerations – Laboratory measurement of noise generated by hydrodynamic flow through control valves IEC 61 298-1 , Process measurement and control devices – General methods and procedures for evaluating performance – Part 1: General considerations IEC 61 298-2, Process measurement and control devices – General methods and procedures for evaluating performance – Part 2: Tests under reference conditions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60534-1 , IEC 60534-2-1 , IEC 61 298-1 , and IEC 61 298-2 apply.
5 Test system
5.1 Test specimen The test specimen is any valve or combination of valve, pipe reducer, and expander or other devices attached to the valve body for which test data are required. See Annex A for additional examples of test specimens representative of typical field installations. Additional considerations apply when testing certain styles of high-capacity control valves, e.g., ball or butterfly valves. These valves may produce free jets in the downstream test section impacting the location of the pressure recovery zone. See Clause 6 for expected accuracies. Fractional C valves (valves where C << N 18 ) are addressed in 8.1.2. Physical or computer-based modelling of control valves as the basis for flow coefficient determination is permissible but is outside the scope of this standard. When modelling, it is incumbent on the practitioner to employ suitable modelling techniques to validate the model and scaling relationships to actual flow data, and to document the nature of the model.The inside diameter (ID) of the pipe normally should be within ± 2 % of the actual inside diameter of the inlet and outlet of the test specimen for all valve sizes. As the C/d 2 ratio (of the test valve) increases, the mismatch in diameters becomes more problematic. Potential pressure losses associated with the inlet and outlet joints become significant in comparison to the loss associated the valve. Also, a significant discontinuity at the valve outlet could affect the downstream (p 2 ) pressure measurement. One indication of the significance of mismatched diameters is the value of the piping geometry factor (F P ) based on the internal diameters. This value approaches unity for a standard test, i.e., for equal line and specimen inside diameters. Therefore, to ensure the proper accuracy for the test, it shall be demonstrated by either calculation or test that 0,99 ≤ F P ≤ 1 ,01 . If F P < 0,99, or F P > 1 ,01 it shall be so noted in the test data (see 8.1 .5 or 1 0.1 .5). See Annex F for a sample calculation. The inside surfaces shall be reasonably free of flaking rust or mill scale and without irregularities that could cause excessive fluid frictional losses. 5.3 Throttling valves The upstream and downstream throttling valves are used to control the pressure differential across the test section pressure taps and to maintain a specific upstream or downstream pressure. There are no restrictions as to style of these valves. However, the downstream valve should be of sufficient capacity, and may be larger than the nominal size of the test specimen, to ensure that choked flow can be achieved at the test specimen for both compressible and incompressible flow. Vaporization at the upstream throttling valve shall be avoided when testing with liquids.