Gauge Manifold Set

The gauge manifold set is one of the most important tools in a mechanics possession. Gauges are used to read system operating pressures, charge, recover and evacuate refrigerant, and asl o can be used to pressure test the system. The Gauge Manifold has a low side gauge on the left (blue) and a high side gauge on the right (red). The left hand wheel and hose are blue. The right hand wheel and hose are red and the middle hose is yellow. This makes it easy to grab the hose you want without having to trace it back.

Lets take a close look at how the manifold actually works. We'll assume you have repaired a leak in a system and are now charging it with refrigerant. You have the blue hose hooked up to the low side of the system, the red hose hooked up to the high side and the yellow hose is hooked up to a jug of refrigerant. Click on the Charge Button and notice all the things that happen.
  • The graphic simulates you turning the blue hand wheel counter clockwise which moves the low side stem away from the seat.
  • This allows the higher pressure refrigerant to flow into the left chamber of the gauge manifold set.
  • From there the refrigerant can flow in 2 directions. It flows into the low side of the system thereby charging it and it also flows into the Bourdon tube of the low side gauge allowing it to register the amount of pressure you are working with.

Images courtesy Refrigeration Basics