use of copper-phosphorous or copper-phosphorous-silver brazing metal
without flux. Brazing of dissimilar metals (copper to bronze or brass)
shall include the use of flux with either a copper-phosphorous,
copper-phosphorous-silver or a silver brazing filler metal. Joints for
flared fittings shall be of the compression pattern. Swing joints or
offsets shall be provided in all branch connections, mains, and risers to
provide for expansion and contraction forces without undue stress to the
fittings or to short lengths of pipe or tubing. Flared or brazed copper
tubing to pipe adapters shall be provided where necessary for joining
threaded pipe to copper tubing.
3.2.6.5
Soldered Joints
Soldered joints shall be made with flux and are only acceptable for lines
50 mm 2 inches and smaller. Soldered joints shall conform to ASME B31.5
and CDA A4015.
3.2.6.6
Copper Tube Extracted Joint
An extruded mechanical tee joint may be made in copper tube. Joint shall
be produced with an appropriate tool by drilling a pilot hole and drawing
out the tube surface to form a collar having a minimum height of three
times the thickness of the tube wall. To prevent the branch tube from
being inserted beyond the depth of the extracted joint, dimpled depth stops
shall be provided. The branch tube shall be notched for proper penetration
into fitting to assure a free flow joint. Extracted joints shall be brazed
using a copper phosphorous classification brazing filler metal. Soldered
joints will not be permitted.
3.2.7
Flanges and Unions
Flanges shall be faced true, provided with 1.6 mm 1/16 inch thick gaskets,
and made square and tight. Where steel flanges mate with cast-iron flanged
fittings, valves, or equipment, they shall be provided with flat faces and
full face gaskets. Union or flange joints shall be provided in each line
immediately preceding the connection to each piece of equipment or material
requiring maintenance such as coils, pumps, control valves, and other
similar items. Dielectric pipe unions shall be provided between ferrous
and nonferrous piping to prevent galvanic corrosion. The dielectric unions
shall have metal connections on both ends. The ends shall be threaded,
flanged, or brazed to match adjacent piping. The metal parts of the union
shall be separated so that the electrical current is below 1 percent of the
galvanic current which would exist upon metal-to-metal contact. Gaskets,
flanges, and unions shall be installed in accordance with manufacturer's
recommendations.
3.2.8
Branch Connections
**************************************************************************
NOTE: Select the appropriate type of branch
connections and delete those which are not required.
**************************************************************************
3.2.8.1
Branch Connections for Hot Water Systems
Branches from the main shall pitch up or down as shown to prevent air
entrapment. Connections shall ensure unrestricted circulation, eliminate
air pockets, and permit complete drainage of the system. Branches shall
pitch with a grade of not less than 8 mm in 1 m 1 inch in 10 feet. When
SECTION 15569A
Page 64
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