1. GAUGE AND MANIFOLD IDENTIFICATION © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

2.  Hello, I want to show you the gauges and manifolds we use at Fresh or Freezing and talk about how we maintain and test them.  There are two main differences in service gauge manifolds, ie normal pressure and high pressure.  Normal pressure manifolds are used for everyday service of refrigeration units, eg R22, R404a systems. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

3.  High pressure manifolds are used for high pressure refrigerants, eg R410A, R764.  The thread size on the manifold and the attached gauge lines determines the usage.  Normal pressure manifolds use 1/4 ” flare threads, whereas high pressure manifolds use 5/16 ” flare threads.  Take care with manifolds fitted with sight glasses as these can be easily damaged and the glass can fly out of the manifold and injure you or somebody else. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

4.  Manufacturers colour code the outside of the gauges to distinguish between high pressure and low pressure gauges.  The low pressure gauge or compound gauge is colour coded blue and the high pressure gauge is colour coded red. Don’t confuse this with the manifold gauge body. It’s not colour coded.  The AC gauge hoses are colour coded blue, red and yellow. Yellow connects to vacuum pump, reclaim unit or charge refrigerant. Blue connects to the low pressure side. Red connects to the high pressure side  Some manufacturers also colour code the hand valves.  The gauge hose ports are not colour coded. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

5.  There are two types of manifold gauges – the standard two valve gauge manifold set and the standard four gauge manifold set. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

6.  Maintaining and calibrating Bourdon tube gauges means following a few simple steps: periodically testing for leaks periodically testing for leaks removing any residual refrigerant then adjusting the needle of the gauge to read 0 kPa at atmospheric pressure removing any residual refrigerant then adjusting the needle of the gauge to read 0 kPa at atmospheric pressure keeping gauge lines sealed to keep out dirt and other contaminants keeping gauge lines sealed to keep out dirt and other contaminants replacing the rubber seals in the ends of the gauge lines, and giving the gauge lines a visual check to look for perishing of the lines, cracks in the outer covering of the lines and any other signs of mechanical damage. replacing the rubber seals in the ends of the gauge lines, and giving the gauge lines a visual check to look for perishing of the lines, cracks in the outer covering of the lines and any other signs of mechanical damage. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

7.  Other types of pressure gauges such as electronic gauges require specialised maintenance. This must be carried out by qualified people.  And remember, if you are unsure about how to calibrate a gauge, check with your manager. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence