Which device measures the vacuum in inches of mercury and outgoing water pressure in psi on the pump's discharge side?

Which device measures the vacuum in inches of mercury and outgoing water pressure in psi on the pump's discharge side?

• A. Intake/Compound gauge
• B. Tank Fill/Recirculating Valve
• C. Engine Cooler Valve
• D. Discharge/Compound gauge

Answer: (D)

Compound gauges are built to read both negative pressure (vacuum) and positive pressure on a single instrument. In pump operation you need to know how hard the pump is pulling on the intake (vacuum, in inches of mercury) and how much pressure the water is delivering on the discharge (psi). A gauge labeled as discharge/compound combines these readings in the discharge area, giving you the discharge pressure in psi while still reflecting the suction side vacuum on the same instrument. That makes it the most appropriate device for monitoring both conditions from the discharge side. The other options are valves or single-parameter gauges and don’t provide the combined vacuum and discharge pressure measurement in one device.

Compound gauges are built to read both negative pressure (vacuum) and positive pressure on a single instrument. In pump operation you need to know how hard the pump is pulling on the intake (vacuum, in inches of mercury) and how much pressure the water is delivering on the discharge (psi). A gauge labeled as discharge/compound combines these readings in the discharge area, giving you the discharge pressure in psi while still reflecting the suction side vacuum on the same instrument. That makes it the most appropriate device for monitoring both conditions from the discharge side. The other options are valves or single-parameter gauges and don’t provide the combined vacuum and discharge pressure measurement in one device.