A Unifying Method for Sizing Throttling Valves Under Laminar or Transitional Flow Conditions

The mass flow passing through a given valve will decrease in Reynolds number ranges below approximately 10,000 due to the transition from fully developed turbulent to laminar flow. The objective of this study is to provide a uniform prediction method to establish, with reasonable accuracy, the ratio between the turbulent and transitional or laminar flow rate passing through a given valve, taking into account the valve’s hydraulic diameter and the initial turbulent velocity head loss coefficient. Experimental data from prior research tends to support a proposed “unified sizing method” that is applicable for all single-stage valves regardless of size or type.