What is the minimum depth of water required to pull a draft using a barrel strainer during a service test?

To effectively draft water using a barrel strainer during a service test, the minimum depth of water is crucial. A depth of at least 4 feet is recommended because this ensures that the strainer is adequately submerged, which is necessary to avoid drawing in air and to maintain a consistent flow of water. Adequate depth helps prevent cavitation and allows for optimal suction, enabling the fire apparatus to draw water efficiently from the source. This depth supports the design and operational requirements of the barrel strainer, which is intended to filter out debris while allowing for maximum flow. Therefore, selecting 4 feet as the minimum depth aligns with established safety and operational standards for fire service testing.