Manual for Refrigeration Servicing Technicians - UNEP - Division of ...

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4 Servicing Practices Purging The process of removing unwanted gases, dirt or moisture from the system is called purging. An inert gas such as nitrogen is introduced in the system to flow through the tubing, forcing unwanted contaminants out. Flow pressure adjustment Flow pressure 1/4’’ male �are �tting for hose connection Cylinder pressure Cylinder connection The following equipment is needed to perform purging: • Oxygen free dry nitrogen cylinder equipped with pressure regulator • Nitrogen cylinder equipped with pressure regulator • Manifold gauges with hoses • Vacuum pump • Two servicing valves (or the system is equipped with servicing valves). NITROGEN 2350 psig 96
CHAPITRE 4 4PAGE 10 LEAK DETECTION Servicing Practices Purging procedure The following steps should be followed when performing system cleaning (purging): 1 - Set the connections as shown here: NITROGEN PRESSURE REGULATOR NITROGEN CYLINDER NITROGEN ESCAPING NITROGEN ESCAPING 2 - As with the evacuation procedure, ensure that all stop valves, solenoid valves and other such devices have been fully opened so not to restrict the flow around any parts of the system. 3 - Open the low-pressure side and high-pressure side valves in the manifold gauges. 4 - Open the nitrogen cylinder main valve using the pressure regulator on the cylinder to keep pressure of OFDN at less than the maximum working pressure indicated on the equipment nameplate. 5 - Keep the OFDN flowing for several minutes or until dry clean gas is discharged, indicating that all the contaminants have been removed. 6 - Remove the residual nitrogen with a vacuum pump using the proper procedure. 97
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Manual for Refrigeration Servicing
Page 3 and 4:
Introduction When to use the manual
Page 5 and 6:
Introduction The Factors affecting
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Introduction How to assess conditio
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Introduction Characteristics of Sel
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Introduction Another form of refere
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Introduction Choose your chapter Th
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1 Environmental impact of refrigera
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1 Environmental Impact The ozone la
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1 Environmental Impact RADIATION FR
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1 Environmental Impact The ozone la
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1 Environmental Impact Effects of o
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1 Environmental Impact The greenhou
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1 Environmental Impact Timeline act
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1 Environmental Impact Alternative
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1 Environmental Impact The way forw
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2 Refrigerants 2.1. Section objecti
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2 Refrigerants Chemical properties
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2 Refrigerants Safety characteristi
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2 Refrigerants Types of refrigerant
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2 Refrigerants Those with ozone dep
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2 Refrigerants Those with zero ozon
Page 45 and 46: 2 Refrigerants Carbon dioxide (CO2,
Page 47 and 48: 2 Refrigerants Azeotropic Blends An
Page 49 and 50: 2 Refrigerants Using Refrigerant Bl
Page 51 and 52: 2 Refrigerants Lubricants Today, al
Page 53 and 54: 2 Refrigerants Refrigerants and app
Page 55 and 56: 2 Refrigerants Properties of most c
Page 57 and 58: 3 Refrigerants Content Management M
Page 59 and 60: 3 Refrigerant Management The majori
Page 61 and 62: 3 Refrigerant Management Handling o
Page 63 and 64: 3 Refrigerant Management Recovery c
Page 65 and 66: 3 Refrigerant Management Refrigeran
Page 67 and 68: 3 Refrigerant Management Refrigeran
Page 69 and 70: 3 Refrigerant Management Open Refri
Page 71 and 72: 3 Refrigerant Management CHAPITRE 3
Page 73 and 74: 3 Refrigerant Management Recycling
Page 75 and 76: 3 Refrigerant Management equipment
Page 79 and 80: 3 Refrigerant Management PAGE 22 Ex
Page 83 and 84: 3 Refrigerant Management Further re
Page 85 and 86: Summary This section will provide t
Page 87 and 88: 4 Servicing Practices Moisture Mois
Page 89 and 90: 4 Servicing Practices Non-condensab
Page 91 and 92: 4 Servicing Practices Evacuation A
Page 93 and 94: 4 Servicing Practices 7 - For large
Page 95: 4 Servicing Practices Pressure unit
Page 99 and 100: 4 Servicing Practices Detection met
Page 101 and 102: 4 Servicing Practices CHAPITRE 4 PA
Page 103 and 104: 4 Servicing Practices Volumetric ch
Page 105 and 106: 4 Servicing Practices Electronic ch
Page 107 and 108: 4 Servicing Practices Why charge re
Page 109 and 110: 5 Retrofitting Content General retr
Page 111 and 112: 5 Retrofitting • Upon evaluation
Page 113 and 114: 5 Retrofitting General retrofitting
Page 115 and 116: 5 Retrofitting procedures that you
Page 117 and 118: 5 Retrofitting MVAC retrofitting pr
Page 119 and 120: 5 Retrofitting Although, in general
Page 121 and 122: 5 Retrofitting Further reading UNEP
Page 123 and 124: 6 Summary 6.1. Overview of refriger
Page 125 and 126: 6 Safe Refrigerant Handling Oxygen
Page 127 and 128: 6 Safe Refrigerant Handling The com
Page 129 and 130: 6 Safe Refrigerant Handling • Nev
Page 131 and 132: 6 Safe Refrigerant Handling Safe ha
Page 133 and 134: 6 Safe Refrigerant Handling leak de
Page 135 and 136: 6 Safe Refrigerant Handling • Lea
Page 137 and 138: 6 Safe Refrigerant Handling Storage
Page 139 and 140: 6 Safe Refrigerant Handling Recomme
Page 141 and 142: 6 Safe Refrigerant Handling 3 - Sho
Page 143 and 144: Glossary Glossary Absolute pressure
Page 145 and 146: Glossary Fossil fuels Carbon-based
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Glossary hole in late 1985, governm
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Glossary Sealed system A refrigerat
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Acknowledgements Acknowledgements I
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Copyright Copyright © United Natio
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