Opening Pressure Test
- Open tester shut off valve to pressure gauge 1/4 turn. Slowly depress tester lever and observe pressure gauge. Note pressure at which needle stopped, indicating pressure increase (nozzle does not chatter) or at which pressure the pressure dropped substantially (nozzle chatters).
- The maximum pressure is the opening pressure. Lowest acceptable pressure is 1500 psi (105 kg/cm2 ). Replace any nozzle which does not meet lowest acceptable pressure. Release tester pressure.