Refrigeration Piping Charging Residential AirConditioning R

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14 Arrange refrigerant piping so that normal inspection and servicing of the compressor and other equipment is not hindered. Do not obstruct the view of the oil level sight glass, or run piping so that it interferes with the removal of compressor cylinder head, end bells, access plates, or any internal parts. Suction line piping to the compressor should be arranged so that it will not interfere with removal of the compressor for servicing. You must provide adequate clearance for insulation installation between the piping, wall, and hangers. Use sleeves that are sized to permit installation of both pipe and insulation through floor, walls, or ceilings. Set the sleeves prior to pouring of concrete or erection of brickwork. Piping must not interfere with passages or obstruct headroom, windows, or doors. Refer to ASHRAE Standard 15, Safety Code for Mechanical Refrigeration, and other governing local codes for restrictions that may apply. Protection Against Damage To Piping Protection against damage is necessary, particularly for small lines, which have a false appearance of strength. Where traffic is heavy, provide protection against impact from pedestrian and motorized traffic. Piping Insulation All piping joints and fittings should be thoroughly leak tested before insulation is sealed. Suction lines should be insulated to prevent sweating and heat gain. Insulation covering lines on which moisture can condense or lines subjected to outside conditions must be vapor sealed to prevent any moisture travel through the insulation, or condensation in the insulation. Although the liquid line ordinarily does not require insulation, the suction and liquid lines can be insulated together. The liquid line should be insulated to minimize heat gain if it passes through an area of higher temperature. Hot gas discharge lines usually are not insulated, however, they should be insulated if the heat dissipated is objectionable or if necessary to prevent injury from high temperature surfaces. 14
15 Vibration & Noise in Piping Two undesirable effects of vibration of refrigerant piping are: 1) physical damage to the piping, which may result in the breaking of brazed joints and consequent loss of charge; and 2) transmission of noise through the piping itself and through building construction with which the piping may come into direct physical contact. Both can be eliminated or minimized by proper piping design and installation. Using Manufacturer’s Pressure Drop & Velocity Charts Always size for pressure drop first, then velocity. On the top right of the pressure drop chart in Figure 8-3, you will find tons of refrigeration or cooling capacity calibrated in Btu per hour up to 1 ton, and in tons of cooling from 1 ton to 100 tons. You start the sizing procedure by drawing a straight line from your system’s designated capacity through the diagonal lines on the right side of the chart. The diagonal lines represent: • The “evaporator temperature”, used to size the suction line. • The “discharge line” temperature, used to size the hot gas discharge. • The “liquid lines” diagonal line, used to size the liquid line. 15
Page 1 and 2: Refrigeration Piping & Charging Res
Page 3 and 4: Piping & Tubing 3 Refrigeration Pip
Page 5 and 6: 5 gravity flow without incurring ba
Page 7 and 8: 7 increases, the operating charge i
Page 9 and 10: 9 temperature R-502 compressor at -
Page 11 and 12: 11 drop is more critical and where
Page 13: 13 Expansion & Contraction Temperat
Page 17 and 18: 17 • First, find 6 tons on the to
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Page 33 and 34: 33 Charging Residential Air Conditi
Page 35 and 36: 35 Low subcooling means that a cond
Page 37 and 38: Charging Methods 37 Before charging
Page 39 and 40: 39 temperature when the refrigerant
Page 41 and 42: 41 service on residential air condi
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Refrigeration Piping Charging Residential AirConditioning R

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