What additional pressure drop will result from adding 2 feet of plumbing and two 90-degree elbows for a new instrument requiring airflow?

To determine the additional pressure drop from adding 2 feet of plumbing and two 90-degree elbows, it is essential to understand how fluid dynamics applies to airflow systems.

When considering pressure drops in an airflow system, both the length of the straight pipe and the fittings like elbows influence the total resistance to flow. In this case, adding 2 feet of plumbing contributes to a linear pressure drop based on the friction and resistance associated with that length. Additionally, every 90-degree elbow introduces a significant increase in pressure drop due to the sudden change in direction of the airflow.

The pressure drop can be calculated using established formulas and tables that relate straight lengths and fittings to pressure losses in similar systems. Each 90-degree elbow has a specific equivalent length that is factored into the overall calculation.

In this scenario, if calculations indicate that the two elbows and the added length of plumbing result in an overall total pressure drop of 0.4455 inches of mercury (in. Hg), then that value accurately reflects the sum of the pressure losses caused by the combined effects of friction from the additional plumbing and the disturbances created by the elbows.

Recognizing this, the number from the initial choice aligns with the technical factors that govern airflow pressure drops in a duct or