Pop testing a nozzle is used to determine

Pop testing a nozzle is used to determine

• A. Pressure differential
• B. Maximum operating pressure
• C. Nozzle leak rate
• D. Spray pattern uniformity

Answer: (A)

Pop testing a nozzle is all about finding the opening pressure—the pressure difference needed to lift the nozzle needle and start fuel flow. As you gradually increase fuel pressure, you watch for the moment the nozzle “pops” open. The pressure at that moment is the opening or differential pressure, which tells you how the nozzle will behave in operation. This is why the test is described as measuring pressure differential. The other options describe different aspects: maximum operating pressure is the highest pressure the nozzle can endure in service, not the opening point; nozzle leak rate requires checking how much fuel leaks when the nozzle is closed or at a test pressure; spray pattern uniformity is about how evenly the fuel is sprayed, which is evaluated with a spray pattern test, not a pop test.

Pop testing a nozzle is all about finding the opening pressure—the pressure difference needed to lift the nozzle needle and start fuel flow. As you gradually increase fuel pressure, you watch for the moment the nozzle “pops” open. The pressure at that moment is the opening or differential pressure, which tells you how the nozzle will behave in operation. This is why the test is described as measuring pressure differential.

The other options describe different aspects: maximum operating pressure is the highest pressure the nozzle can endure in service, not the opening point; nozzle leak rate requires checking how much fuel leaks when the nozzle is closed or at a test pressure; spray pattern uniformity is about how evenly the fuel is sprayed, which is evaluated with a spray pattern test, not a pop test.