BS EN 723-2009 pdf download.Copper and copper alloys Combustion method for determination of the carbon content on the inner surface of copper tubes or fittings.
a) For tubes:
The beaker shall contain sufficient solution to cover between 75 mm and 125 mm of the length of the sample (the smaller the diameter of the tube being tested, the greater the depth of immersion required to ensure a sufficiently covered surface area).
b) For fittings:
The beaker shall contain a sufficient quantity of solution to cover the sample. Refresh the acid bath weekly or after preparation of about forty samples (whichever is the sooner).
1) see EN 1173 for the explanation of R250 and R290.
Ensure that the sample remains in the acid solution for at least 30 s so that copious quantities of brown fumes
(NO2) are expelled. This step of operation shall be performed in a fume cupboard.
Withdraw the sample from the acid solution and rinse thoroughly with deionised water.
Transfer the sample to a bath containing boiling deionised water for a duration between 30 s and 60 s, which, before use shall have been boiled for approx. 5 mm to ensure a complete degassing of the water, or rinse the sample with hot (mm. 50 °C) running water for at least 30 s. Take care to ensure that the useful part of the sample is fully immersed in the water bath. Due to an uptake of CO2 from the air, refresh the deionised water every day or after the preparation of about forty samples (whichever is sooner).
Remove the sample from the bath and place it vertically under a fume hood or on a grease-free plate in an oven operating at a temperature of at least 80 C for a minimum of 60 s, until the water has totally evaporated or let it dry on air.
4.3.2.3 Mechanical cleaning
Hold the tube in a vice and remove all traces of the outer surface in the area to be tested, using a degreased file.
Alternatively, a thin layer from the outer surface may be removed by turning on a lathe using a tool with a degreased tip.
All tools used for mechanical cleaning shall be free of organic contamination. The tools shall not be used for other mechanical operation
4.4 Preparation of test pieces
4.4.1 Tubes
4.4.1.1 General
Carry out the procedure given in 4.4.1.2 or 4.4.1.3, depending on the tube diameter, and taking account of the
precautions described in 4.1.
4.4.1.2 Tubes with diameters not exceeding the furnace diameter
From the cleaned sample, cut and discard a 2,5 cm length, from one end which, in the case of a chemically cleaned outer surface, shall be from the plugged or flattened end of the tube (having firstly removed the plug from the tube end if appropriate).
Measure the required length of tube using a clean measuring device to yi&d an internal surface area between 20 cm2 and 25 2
Cut off the required length using either a clean, square-cut auto-saw used only for such purposes or a degreased, fine-toothed hacksaw, avoiding overheating the sample. If the test piece is longer than the zone of incandescence of the combustion device described in 5.1 c), cross-cut the test piece into two, in order that both pieces may be fed simultaneously into the zone of incandescence. Take care to ensure that the cut is square. If using an auto-saw, take also care to ensure that all surfaces with which the tube is In contact are thoroughly degreased. When filing and cutting tubes, take care to ensure that the section of tube being held in position (e.g. between the jaws of a vice) is not excessively distorted.
Determine the internal surface area of the test piece from its mean internal diameter and mean length,
measured to an accuracy of ± 0,1 mm.
NOTE If the cross-cut leads to a loss of length, it should be taken into account for the surface area determination.BS EN 723-2009 pdf download.
BS EN 723-2009 pdf download
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