What percentage reduction occurs when three 90-degree elbows are used?

What percentage reduction occurs when three 90-degree elbows are used?

• A. 5%
• B. 0%
• C. 15%
• D. 10%

Answer: (D)

When fittings are added to a gas line, each one creates some resistance and turbulence, causing a drop in the available pressure. A 90-degree elbow contributes a small, roughly constant amount of loss, and the losses add up with multiple elbows. For three 90-degree elbows, the cumulative effect is about ten percent of the system pressure being lost to the fittings. That’s why ten percent is the best answer. Zero percent would ignore losses from any fittings, which isn’t accurate. Five percent would underestimate the cumulative impact of three elbows, while fifteen percent would overstate it for this configuration.

When fittings are added to a gas line, each one creates some resistance and turbulence, causing a drop in the available pressure. A 90-degree elbow contributes a small, roughly constant amount of loss, and the losses add up with multiple elbows.

For three 90-degree elbows, the cumulative effect is about ten percent of the system pressure being lost to the fittings. That’s why ten percent is the best answer.

Zero percent would ignore losses from any fittings, which isn’t accurate. Five percent would underestimate the cumulative impact of three elbows, while fifteen percent would overstate it for this configuration.