Flow rate scale field calibration for balancing valve

Apparatus, including a balance or flow limiting valve, comprising:

• a valve body 12 configured with a flow rate indicator or scale 44 containing settings each having a printed flow rate calibrated in appropriate units of measure in volume per time increment between minimum and maximum flow rate positions;
• and
• a knob 48 having a position indicator 48a and being configured to be mounted to any continuous position on the flow rate indicator or scale 44 between the minimum and maximum flow rate positions in response to force applied by a user,
• where the relationship between the flow rate indicator or scale 44 of the valve body 12 and the position indicator 48a of the knob 48 is based at least partly on calibrated flow characteristics of the balance or flow limiting valve, so that the user can set a substantially exact desired flow rate in one operation by moving the knob 48 to a desired position between the minimum and maximum flow rate positions without consulting a printed flow curve or other form of a balance calculator to determine the desired exact flow rate of the balance or flow limiting valve, characterized in that
• the valve body 12 is configured with a cavity 12a to receive a combination of a seal 14a, a ball 14b, a seat 14c, an O-ring 14d and a ball retainer 14e,
• the valve body 12 is also formed with a second cavity coupled to the first cavity and configured to receive a combination of a pressure/temperature port stem 20 and a stem bonnet bushing 22,
• the balancing valve 10 includes an on/off handle 24 having a handle retaining portion 24a and also includes a retaining ring 26 configured to attach to the pressure/temperature port stem 20, so as to couple together the pressure/temperature port stem 20, the stem bonnet bushing 22 and the handle retaining portion 24a, so that the on/off handle 24 can turn the pressure/temperature port stem 20,
• the valve body 12 is also formed with a third cavity configured to receive a pressure/temperature port 30,
• the valve body 12 is also formed with a fourth cavity/that is coupled to the third cavity , and is also configured to receive a combination of a flow pressure regulating cartridge 40, a cartridge retainer 42 and the flow rate scale or indicator 44, wherein the knob 48 is configured in relation to the flow rate scale or indicator 44 and the cartridge retainer 42, is coupled to the flow pressure regulating cartridge 40 and is configured to be rotated in relation to the flow rate scale or indicator 44 and to turn the flow pressure regulating cartridge 40 so as to determine the flow rate of the balancing valve 10.