What is the maximum recommended head loss for positive displacement water meters that are less than 2 in.?

The maximum recommended head loss for positive displacement water meters that are less than 2 inches indicates the pressure drop that is acceptable across the meter during operation. A head loss of 15 psi is cited as a standard limit because exceeding this can lead to inaccuracies in measurement and hinder the performance of the meter. Positive displacement meters operate by measuring the volume of water that passes through them, and significant pressure loss could affect the flow characteristics, causing the meter to misread the flow rate.

In practice, maintaining head loss within this range ensures optimal meter performance and longevity. Going beyond this limit could lead to a loss of accuracy and may cause operational issues, impacting overall system efficiency. Choosing a more stringent limit like 15 psi helps in ensuring that the meter’s calibration remains stable and provides reliable readings across varying flow conditions.