The valve flow coefficient, also known as the flow rate, is the rate at which media flows through the valve and the amount by which the flow pressure changes (drops) across the valve. The flow rate is affected by the state and viscosity of the media, as well as the valve size, type, and diameter of the pipe connections. A formula can be used to calculate the flow rate value; the larger the value, the higher the flow rate through the valve at a given pressure drop. Flow rate is expressed as Cv or Kv depending on the measurement system used (imperial or metric, respectively). The minimum required Cv value is frequently listed in a valve’s product description or elsewhere in its specifications. Flow coefficient in imperial units = Cv value As follows: The flow rate of water in gallons per minute (gpm) in the United Read more