GAUGE AND GAUGE AND MANIFOLD MANIFOLD

IDENTIFICATIONIDENTIFICATION

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Hello, I want to show you the Hello, I want to show you the gauges and manifolds we use at gauges and manifolds we use at Fresh or Freezing and talk about Fresh or Freezing and talk about how we maintain and test them. how we maintain and test them.

There are two main differences in There are two main differences in service gauge manifolds, ie normal service gauge manifolds, ie normal pressure and high pressure.pressure and high pressure.

Normal pressure manifolds are Normal pressure manifolds are used for everyday service of used for everyday service of refrigeration units, eg R22, R404a refrigeration units, eg R22, R404a systems.systems.

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High pressure manifolds are used for high High pressure manifolds are used for high pressure refrigerants, eg R410A, R764. pressure refrigerants, eg R410A, R764.

The thread size on the manifold and the attached The thread size on the manifold and the attached gauge lines determines the usage.gauge lines determines the usage.

Normal pressure manifolds use Normal pressure manifolds use 1/41/4” flare threads, ” flare threads, whereas high pressure manifolds use whereas high pressure manifolds use 5/165/16” flare ” flare threads.threads.

Take care with manifolds fitted with sight glasses Take care with manifolds fitted with sight glasses as these can be easily damaged and the glass as these can be easily damaged and the glass can fly out of the manifold and injure you or can fly out of the manifold and injure you or somebody else.somebody else.

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Manufacturers colour code the Manufacturers colour code the outside of the gauges to outside of the gauges to distinguish between high pressure distinguish between high pressure and low pressure gauges. and low pressure gauges.

The low pressure gauge or The low pressure gauge or compound gauge is colour coded compound gauge is colour coded blue and the high pressure gauge blue and the high pressure gauge is colour coded red. Don’t confuse is colour coded red. Don’t confuse this with the manifold gauge this with the manifold gauge body. It’s not colour coded.body. It’s not colour coded.

The AC gauge hoses are colour coded blue, red and The AC gauge hoses are colour coded blue, red and yellow. Yellow connects to vacuum pump, reclaim yellow. Yellow connects to vacuum pump, reclaim unit or charge refrigerant. Blue connects to the low unit or charge refrigerant. Blue connects to the low pressure side. Red connects to the high pressure sidepressure side. Red connects to the high pressure side

Some manufacturers also colour code the hand Some manufacturers also colour code the hand valves.valves.

The gauge hose ports are not colour coded.The gauge hose ports are not colour coded.© Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

There are two types of There are two types of manifold gauges – the manifold gauges – the standard two valve gauge standard two valve gauge manifold set and the manifold set and the standard four gauge standard four gauge manifold set. manifold set.

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Maintaining and calibrating Maintaining and calibrating Bourdon tube gauges means Bourdon tube gauges means following a few simple steps:following a few simple steps: periodically testing for leaksperiodically testing for leaks removing any residual removing any residual

refrigerant then adjusting refrigerant then adjusting the needle of the gauge to the needle of the gauge to read 0 kPa at atmospheric read 0 kPa at atmospheric pressurepressure

keeping gauge lines sealed keeping gauge lines sealed to keep out dirt and other to keep out dirt and other contaminantscontaminants replacing the rubber seals in the ends of the replacing the rubber seals in the ends of the

gauge lines, and giving the gauge lines a visual gauge lines, and giving the gauge lines a visual check to look for perishing of the lines, cracks in check to look for perishing of the lines, cracks in the outer covering of the lines and any other signs the outer covering of the lines and any other signs of mechanical damage.of mechanical damage.

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Other types of Other types of pressure gauges pressure gauges such as electronic such as electronic gauges require gauges require specialised specialised maintenance. This maintenance. This must be carried out must be carried out by qualified people. by qualified people.

And remember, if And remember, if you are unsure about you are unsure about how to calibrate a how to calibrate a gauge, check with gauge, check with your manager. your manager.

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