標準號：BS EN 60534-2-5-2003
中文標準名稱：工業過程控制閥.流通能力.通過有段間恢復功能的多段控制閥的流體流量的校準公式
英文標準名稱：Industrial-process control valves - Flow capacity - Sizing equations for fluid flow through multistage control valves with interstage recovery
標準類型：N16
發布日期：2003/11/7 12:00:00
實施日期：2003/11/7 12:00:00
中國標準分類號：N16
國際標準分類號：23.060.40;25.040.40
適用范圍：This part of IEC 60534 includes equations for predicting the flow of compressible and incompressible fluids through multistage control valves. The equations for incompressible flow are based on standard hydrodynamic equations for Newtonian incompressible fluids. They are not intended for use when non-Newtonian fluids, fluid mixtures, slurries, or liquid-solid conveyance systems are encountered. At very low ratios of pressure differential to absolute inlet pressure (△p/p1), compressible fluids behave similarly to incompressible fluids. Under such conditions, the sizing equations for compressible flow can be traced to the standard hydrodynamic equations for Newtonian incompressible fluids. However, increasing values of △p/p1 result in compressibility effects which require that the basic equations be modified by appropriate correction factors. The equations for compressible fluids are for use with gas or vapour and are not intended for use with multiphase streams such as gas-liquid, vapour-liquid or gas-solid mixtures. This standard is applicable only to those designs of multistage multipath control valves and multistage single path control valves.