How are Cv control valves calculated?
Table of Contents
How are Cv control valves calculated?
The equation for calculating the valve flow coefficient is Cv = Q √ (SQ/P).
How do you measure a ball valve Cv?
CV value is an imperial measure of flow in US gallons per minute of water at 60° fahrenheit with a pressure drop of 1 psi across the valve….3 Way Full Bore Flanged Ball Valves.
| Size | Cv | Kv (m3/h) |
|---|---|---|
| 1-1/4″ | 58.4 | 50 |
| 1-1/2″ | 112 | 96 |
| 2″ | 224.1 | 192 |
| 2-1/2″ | 308.1 | 264 |
How do you convert Cv to flow rate?
The volume flow rate for liquids can be calculated by multiplying the fluid velocity times the flow area. Thus, Cv is numerically equal to the number of U.S. gallons of water at 60°F that will flow through the valve in one minute when the pressure differential across the valve is one pound per square inch.
How do you size a ball valve?
If the internal diameter (ID) of the hose is close to 2” you will need a 2” ball valve, or if the external diameter of the male thread is close to 2” you will need a 2” ball valve.
How do you convert KV to Cv?
Kv = 0.864 Cv In metric units, the same valve with Cv = 1 pass 0.864 m3/hr.
How do you convert Cv to K value?
Converting between Flow Coefficient Cv and Flow Factor K. The relationship between Cv and Kv can be expressed as: Cv = 1.16 Kv (1)
What is the difference between Cv and GPM?
Flow coefficient (Cv for control valve) is the capability of a valve to flow a liquid. One Cv is equal to a flow of 1 gallon per minute (gpm) of water at 60 degrees Fahrenheit with a pressure differential of 1 pound per square inch. The larger the Cv, the greater the flow in gpm.
How do you calculate gpm from Cv rating?
Flow Calculations and Cv Values Flow is proportional to the value of Cv. For example, a Cv of 150 would then equate to 150 gpm of water at 60° F with a differential pressure of one psi.
What are the sizes of valves?
Types of valves and their typical operating sizes.
| Type of Valve | Minimum Size | Maximum Size |
|---|---|---|
| mm | inches | |
| Ball | 6 | 48 |
| Butterfly | 50 | 72 |
| Butterfly Neck | 25 | 72 |
How do I choose a ball valve?
The right valve choice means matching the valve’s size to expected flow through the system. Know the chemical compatibility requirements. The valve materials need to be compatible with the gases or liquids flowing through it. Plastic valves usually resist harsh or corrosive chemicals better than metal valves.
