Pump 1 delivers liquid through throttle valve 3 and three-way valve 4. The required pressure, developed by throttle valve 3, is controlled by pressure gauge 5. Liquid flows from the three-way valve to gauging tank 2 and the amount of liquid is measured after a definite time interval. Such measurement is also made without pressure which is relieved by opening throttle valve 3. With valve 4 in the position shown by the dash lines, the liquid drains back to the tank. Valve 6 serves to drain the liquid from the gauging tank back to the tank.
$3724$SHP,M$