What type of gauge is used to check the pump intake pressure?

The pump intake pressure is measured using a compound gauge, which is specifically designed to register both positive and negative pressures. This makes it particularly useful in situations where the pump may be drawing water from various sources, including those that can lead to vacuum (negative pressure) conditions. The compound gauge typically has a dual scale, displaying pressure in both psi (pounds per square inch) for positive pressure and inches of mercury (inHg) for vacuum or negative pressure.

This capability allows operators to accurately monitor intake conditions and ensure that the pump is functioning correctly and efficiently. Understanding intake pressure is crucial for performance management of the pumping system, as both insufficient and excessive intake pressures can lead to operational challenges or equipment damage.

Other instruments mentioned, such as flow meters and digital manometers, serve different purposes. Flow meters measure the volume of water being pumped but do not provide pressure readings. Digital manometers can be used for precise pressure measurements, but they are not a standard tool for routine monitoring of pump intake pressure in fire service applications. Pressure relief valves are safety devices that prevent overpressure in a system but do not measure intake pressure. Therefore, the compound gauge is the correct choice for checking pump intake pressure in mobile water supply operations.