Medium Connections Multi-DENCO
66 FläktGroup DC-2013-0101-GB • Subject to modifications • R5-08/2020
6.2.7 Cutting tubes
Where appropriate, pipework and cables shall be sleeved when passing through build-
ing walls or roof structures.
When cutting copper tubing or pipe, care must be exercised to prevent the filings or
cuttings from entering the pipe. Some effective means should be used to clean out the
small particles of copper when they do enter the tube or pipe. When cutting copper tub-
ing with a wheel cutter, it is extremely important to use sharp wheels. The copper wears
the edge of the wheels more quickly than might be expected; therefore the condition of
the wheel must be checked regularly. Always ream the tube ends to remove burrs.
6.2.8 Brazing
Brazed joints are to be made with Easy-Flo
®
or similar copper alloy rod. Flux is not
required for joining copper to copper. When bronze or brass is involved, Silver-Flow
®
self-fluxing rod or similar is required.
It is necessary to create a positive pressure inside the pipe. Before applying heat to
pipes, remove Schrader valve cores and open any other valves, solenoids etc. which
will cause a build-up of pressure in the line and, therefore, blowholes in the joint. Also,
any valve seats, gaskets, capillaries etc. that may be damaged by heat, flux or dry
nitrogen must be removed or protected, (e.g. wrap in a cold damp cloth.).
When making soldered or brazed joints, it is essential that the surfaces to be joined are
clean. Unclean metals do not take the flux properly, which results in bare spots over
the brazing alloy and will not flow. Thin films of soldering alloy make the strongest
joints. Clearances of between 0.02 mm to 0.07 mm are all that are required. Too much
clearance prevents the proper capillary action, wastes alloy, promotes a weak joint and
allows ingress of soldering material in the lines. After completion of joints ensure that
all surplus flux is thoroughly cleaned off. Flux left on the pipes looks unsightly and can
cause oxidisation, pitting and prematurely age the tubing.
NOTE!
We recommend using a wheel cutter as the best method for cutting pipework.
NOTE – IMPORTANT!
When soldering or brazing, purge a small amount of dry nitrogen through the
pipe to prevent oxidation and scaling internally. Failure to purge nitrogen whilst
brazing will result in scale build up and this WILL block the
Electronic Expansion Valve (EEV).
Any subsequent scale found within the valve body may result in voiding of
warranty!
To Next Page
Loading...
