In general, a 3/8 inch aircraft high-pressure flexible hose compared to the same-size metal tubing in the same system will:

In general, a 3/8 inch aircraft high-pressure flexible hose compared to the same-size metal tubing in the same system will:

• A. Have higher flow capabilities
• B. Have equivalent flow characteristics
• C. Usually have interchangeable applications
• D. Have lower flow capabilities

Answer: (B)

The key idea is that flow capacity in a line is governed mainly by the inside diameter. For a given nominal size, a 3/8 inch aircraft high-pressure flexible hose and a 3/8 inch metal tubing have essentially the same internal cross-sectional area, so the resistance to flow and the resulting pressure loss for a given flow rate are about the same. The hose’s flexibility and its lining affect routing, vibration damping, and pressure ratings more than how much fluid can pass through at that size. So, in general, they behave similarly in terms of flow characteristics. The differences you’d notice are more about installation and handling (flexible routing, weight, bend radius, vibration) and about pressure ratings and compatibility, not about a significantly greater or lesser flow capacity. That's why the best choice is that they have equivalent flow characteristics.

The key idea is that flow capacity in a line is governed mainly by the inside diameter. For a given nominal size, a 3/8 inch aircraft high-pressure flexible hose and a 3/8 inch metal tubing have essentially the same internal cross-sectional area, so the resistance to flow and the resulting pressure loss for a given flow rate are about the same. The hose’s flexibility and its lining affect routing, vibration damping, and pressure ratings more than how much fluid can pass through at that size. So, in general, they behave similarly in terms of flow characteristics.

The differences you’d notice are more about installation and handling (flexible routing, weight, bend radius, vibration) and about pressure ratings and compatibility, not about a significantly greater or lesser flow capacity. That's why the best choice is that they have equivalent flow characteristics.