GB/T 17213.2-2005
Industrial-process control valves.Part 2-1:Flow capacity.Sizing equations for fluid flow under installed conditions (English Version)

Standard No.: GB/T 17213.2-2005
Language: Chinese, Available in English version
Release Date: 2005
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Status: Be replaced 2018-07
Replace By: GB/T 17213.2-2017
Latest: GB/T 17213.2-2017

Scope: This part of GB/T 17213 includes calculation formulas for predicting the flow of compressible fluid and incompressible fluid flowing through control valves. The formulation for incompressible fluids is derived from the standard hydrodynamic equations for Newtonian incompressible fluids, which cannot be extended to non-Newtonian fluids, mixed fluids, suspensions, or two-phase fluids. When the ratio of differential pressure to inlet pressure (△p/p₁) is very low, the properties of compressible fluids are similar to incompressible fluids. In this case, the formulas given in this section can be derived from the basic Bernoulli equations for Newtonian incompressible fluids. However, when the value of △p/p₁ increases, it will cause a compression effect, which requires an appropriate correction coefficient to correct the basic equation. The formulas presented in this section apply to gases or vapors, not to multiphase flows of gas-liquid, vapor-liquid or gas-solid mixtures. For compressible fluid applications, this section is valid for control valves with x_T≦0.84 (see Table 2). For control valves (some multi-pole valves) with x_T>0.84, there is a large error. Reasonable accuracy can only be maintained when K_V/d²<0.04 (C_V/d²<0.047).

GB/T 17213.2-2005 Referenced Document

GB/T 17213.1-1998 Industrial-process control valves. Part 1: Control valve terminology and general considerations
GB/T 17213.9-2005 Industrial-process control valves.Part 2-3: Flow capacity.Test procedures

2017 GB/T 17213.2-2017 Industrial-process control valves—Part 2-1: Flow capacity—Sizing equations for fluid flow under installed conditions
2005 GB/T 17213.2-2005 Industrial-process control valves.Part 2-1:Flow capacity.Sizing equations for fluid flow under installed conditions