What is the closed circuit refuel pressure?

What is the closed circuit refuel pressure?

• A. 10 psi
• B. 20 psi
• C. 25 psi
• D. 15 psi

Answer: (D)

The fuel system uses a controlled, relatively low pressure for fueling when in closed-circuit mode. This keeps fuel moving through the aircraft’s refueling loop safely and reliably, without stressing hoses, fittings, or the regulator. The design sets the closed-circuit refuel pressure at about 15 psi, which provides a steady flow to fill the tanks while minimizing foaming and overpressure risks. Pressures much lower would slow fueling and risk incomplete fill or air pockets; pressures higher than this could exceed the system’s safe operating range and potentially cause leaks or venting issues. That’s why 15 psi is the standard value for closed-circuit refueling.

The fuel system uses a controlled, relatively low pressure for fueling when in closed-circuit mode. This keeps fuel moving through the aircraft’s refueling loop safely and reliably, without stressing hoses, fittings, or the regulator. The design sets the closed-circuit refuel pressure at about 15 psi, which provides a steady flow to fill the tanks while minimizing foaming and overpressure risks.

Pressures much lower would slow fueling and risk incomplete fill or air pockets; pressures higher than this could exceed the system’s safe operating range and potentially cause leaks or venting issues. That’s why 15 psi is the standard value for closed-circuit refueling.