Imperial measure flow in us gallons per minute of water at 60 fahrenheit with pressure drop of 1 psi across the valve. C v coefficient of volume is the number of u s.
V 5252 19 with a cv 350 weighs approximately 200 pounds.
Butterfly valve cv curve. Piping systems dimensions of pipes and tubes materials and capacities pressure drop calculations and charts insulation and heat loss diagrams. Butterfly valves are less expensive. Cv value of valtorc series butterfly valves the valve cv is the flow rate in us gal min of pure water at 60f passing through the valve when the valve disc is fully opened and the pressure differential between the two ends of the valve is i lbfhn 2 cv v v.
The full closure curve of a butterfly valve is then the above graph multiplied by the valve s flow coefficient or factor. They require less space and are lighter. Butterfly valves even though we work on a metric system measures of flow are commonly given as a cv value which is an.
In contrast a 4 in. Cv flow coefficient of butterfly valves depending on the opening position. Vf series butterfly valve with a cv 496 at 70 rotation weighs only 19 pounds including a va 909x series actuator.
Butterfly valve cv values vary with the disc angle and valve size. For example a 6 in. Valve flow coefficients.
In the chart below we show the approximate cv value of butterfly valves ranging from 2 to 24 and at various disc angles. Cv gpm psi nps inches dn mm open disc position. Specific gravity 1 for water.
The chart below records this cv factor for the flowseal valve classes and sizes at ten degree increments between open and closed. Butterfly valves are more compact. Ball valve flow coefficients c v flow coefficients c v for typical ball.
Cv valve coefficient gpm water flow rate in gallons per minute. Gallons per minute of water required to pass through a valve with a pressure drop of 1 psi. Control valves control valve terminology bodies trim flow characteristics cv and kv sizing noise actuators and positioners.
This graph shows the cv or kv valve fraction vs opening and closing angle of a butterfly valve. Cv kv fraction vs angle closure curve chart. Flow in us gal min g.