Download Guide to Good Commercial Refrigeration Practice Part 4 System

Guide to Good Commercial Refrigeration Practice Part 4 System Installation •
Flared Joint: These joints should only be used where other means of jointing are impractical due to the weakness of this type of joint and the environmental impact of refrigerants. This is achieved by the use of a flare nut for the respective size of pipe (1/4” OD, 1/2” OD, etc.) being slipped over a prepared end of copper tube. The end of the copper tube is then flared outward to an angle of approximately 45°. The flare nut is then connected to a flared fitting or component, forming a vapour proof joint. •
Swaged Joints: Swaging of joints in copper pipework permits two pieces of tube of the same diameter to be joined together without the use of fittings, it being more convenient to braze one joint than two with the use of connectors and improves risk against leakage. Less joints, less leaks, containment being the major requirement of the F‐Gas regulations. To achieve a swaged joint, one piece of tubing is swaged out to the outside diameter of the other piece. As a general rule the length of overlap should equal the outside diameter of the tube. Generally the use of swaged joints in copper pipework is acceptable, however on the larger sizes there is a possibility of thinning the wall of the tube, thereby leading to problems of leakages later. Therefore the maximum size of pipe where swaging is acceptable is 1 5/8". All pipework above this diameter shall be joined using standard copper‐to‐copper couplings. Two types of swaging tools are commonly used; the punch type for smaller diameter tubes and the mechanical expander type. With both types, different tool sizes are available for use with the many sizes of copper tubing. The swage is then brazed to achieve a leak proof joint. See also Section 10 sub‐section 29 relating to pulled tees. •
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4.5.6 Flanged Joints: Where pipework has to bolt onto items of equipment, such as compressors, a flange joint is used. The actual joint being formed by a gasket which sits between the two flanges, thus forming a leak proof joint. The jointing of the copper pipework to the flange is achieved by brazing. Lok‐Ring: Brass Lokring fittings are now available to suit refrigeration and air conditioning pipework up to 7/8”. Designed for working pressures up to 50 bar and therefore a preferred acceptable alternative to brazing particularly in locations where hot works is prohibited COPPER ‐ INSTALLATION OF LINE COMPONENTS Before any components are fitted into a refrigeration system it is important that the installer understands where within the system they have to be fitted, the correct methods to be used to fit them and the correct orientation for satisfactory operation. Further information on various components of the refrigeration system can be found in Section 2. British Refrigeration Association 14 Institute of Refrigeration