# Flow Coefficient Cv versus Flow Factor Kv

## Comparing flow coefficient Cv and flow factor Kv

The flow coefficient - Cv - or the flow factor - Kv - are commonly used to specify capacities of control valves.

### Flow Coefficient - Cv

It is often convenient to express the capacity and flow characteristic of a control valve in terms of the

• Flow Coefficient - Cv

The flow coefficient - Cv - is based on the imperial units system and is defined as:

• the flow of water through a valve at 60 oF in US gallon/minute at a pressure drop of 1 lb/in2

The flow coefficient is commonly used in the U.S.

### Flow Factor - Kv

The metric equivalent of the flow coefficient - Cv - is based on the SI-system and is called the

• Flow Factor - Kv

The flow factor - Kv - is defined as

• the flow of water with temperature ranging 5 - 30 oC through a valve in cubic meters per hour (m3/h) with a pressure drop of 1 bar

The flow factor is commonly used outside U.S.

### Converting between Flow Coefficient Cv and Flow Factor Kv

The relationship between Cv and Kv can be expressed as:

• Cv = 1.16 Kv                            (1)
• Kv = 0.862 Cv                          (2)

## Related Topics

• Steam and Condensate - Steam & condensate systems- properties, capacities, pipe sizing, systems configuration and more
• Control Valves - Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators and positioners
• Fluid Mechanics - The study of fluids - liquids and gases. Involves velocity, pressure, density and temperature as functions of space and time
• Process Control - Instrumentation and process control systems, design and documentation
• Control Valves and Equipment - Sizing and dimensions of control valves & equipment in steam and condensate systems
• Piping Systems - Dimensions of pipes and tubes, materials and capacities, pressure drop calculations and charts, insulation and heat loss diagrams
• Pipe Sizing - Sizing steam and condensate pipes - pressure loss, recommended velocity, capacity and more

## Search the Engineering ToolBox

- "Search is the most efficient way to navigate the Engineering ToolBox!"

## Engineering ToolBox - SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your SketchUp model with the Engineering ToolBox - SketchUp Extension/Plugin - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Translate the Engineering ToolBox!