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Orange County West Campus Office Building -HVAC <br />PDC Project 23020 Refrigerant Piping 23 23 00 - 5 <br />2.Support horizontal piping as indicated. <br />3.Place hangers within 12 inches of each horizontal elbow. <br />4.Provide copper plated hangers and supports for copper piping. <br />I.Arrange piping to return oil to compressor. Provide traps and loops in piping,and provide double <br />risers as required. Slope horizontal piping 0.40 percent in direction of flow. <br />J.Provide clearance for installation of insulation and access to valves and fittings. <br />K.Flood piping system with nitrogen when brazing. <br />L.Fully charge completed system with refrigerant after testing. <br />3.03 FIELD QUALITY CONTROL <br />A.Test refrigeration system in accordance with ASME B31.5. <br />B.All refrigerant equipment not tested at the factory shall be shut off from the rest of the system and <br />tested under a vacuum with no evidence of leakage. Piping systems shall be tested after <br />installation,and before any insulation is applied. All controls and other apparatus that may be <br />damaged by the test pressure shall be removed before tests are made. <br />C.Refrigerant piping leak testing shall be as follows,unless equipment manufacturer mandates or <br />recommends or more stringent procedure: <br />1.Connect the refrigerant manifold gauge hoses to the liquid side and gas side service ports on <br />the equipment and connect the center hose to a nitrogen tank fitted with a pressure regulator. <br />2.Fill the lines with nitrogen to 590 psi but no more than 595 psi. <br />3.Monitor the pressure periodically for a minimum of 24 hours.If the pressure drops,use soapy <br />water to check for leaks.Bubbles will occur if joints are not tight. <br />4.Repair leaks.Repeat the previous steps until the pressure remains constant for 24 hours. <br />5.Maintain 145 psi of pressure for 15 minutes and check for further leakage.If the pressure <br />drops,check for leaks and repair.Repeat this step until 145 psi of pressure is maintained for <br />15 minutes. <br />6.Remove hoses from service ports. <br />D.Evacuation Procedure.After performing leak test,use a vacuum pump to triple evacuate the <br />system as described below: <br />1.Use a vacuum pump with a check valve to prevent pump oil from flowing backward while the <br />vacuum pump is closed.Completely close the liquid-vapor line service valves of the outdoor <br />unit. <br />2.Using vacuum-rated hoses,connect the manifold gauges to the liquid and suction (and high <br />pressure,if applicable)gas pipes. <br />3.Evacuate the system to 750 microns,hold for 5 minutes,and check for leaks.Repair and <br />repeat as necessary until vacuum holds. <br />4.Break the vacuum by applying 10 psi of nitrogen. <br />5.Evacuate the system to 500 microns,hold for 5 minutes,and check for leaks.Repair and <br />repeat as necessary until vacuum holds. <br />6.Break the vacuum by applying 10 psi of nitrogen. <br />7.Evacuate the system to 200 microns.Wait for 15 minutes.A rise of no more than 200 microns <br />is acceptable.If over 400 microns,check for leaks,repair,and repeat. <br />8.If under 400 microns,continue holding vacuum for 2.5 hours.If vacuum exceeds 400 microns <br />at end of period,check for leaks,repair,and repeat. <br />9.If system holds under 400 microns for 2.5 hours,system is ready for charging. <br />3.04 SCHEDULES <br />A.Hanger Spacing for Copper Tubing. <br />1.1/2 inch,5/8 inch,and 7/8 inch OD: Maximum span,5 feet;minimum rod size,1/4 inch. <br />2.1-1/8 inch OD: Maximum span,6 feet;minimum rod size,1/4 inch. <br />3.1-3/8 inch OD: Maximum span,7 feet;minimum rod size,3/8 inch. <br />4.1-5/8 inch OD: Maximum span,8 feet;minimum rod size,3/8 inch. <br />5.2-1/8 inch OD: Maximum span,8 feet;minimum rod size,3/8 inch. <br />Docusign Envelope ID: 8DED1454-68D2-4E36-9FC6-E56FF2124E5D