GAUGE MANIFOLD SET
One of the most important tools to the HVACR technician is the gauge manifold set. The compound gauge (blue)
and the high pressure gauge (red) are connected to the manifold, and the manifold is then connected by hoses
to access ports to measure system pressures. The compound gauge measures low pressure (psig) and vacuum
(inches Hg.). The high pressure gauge measures high side (discharge) pressure. The manifold is also equipped
with a center port, (usually a yellow hose), that can be connected to a recovery device, evacuation vacuum
pump, or charging device. EPA regulations require that hoses be equipped with low loss fittings that will mini‐
mize refrigerant loss when hoses are disconnected.
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