Last updated on September 3rd, 2023 at 11:09 am
The pressure in a liquid is exerted in all directions and this phenomenon of a liquid is used for testing bursting strength in hydraulic bursting strength tester.
The specimen for this test should be cut so that the sample is ½ inch greater in diameter of the clamp ring. Ten specimens are chosen avoiding inclusion of the same ends in the different specimens.
The instrument used for testing bursting strength should have a constant rate of speed and must be capable of giving a uniform displacement of 6 ± 0.25 cubic inches per minute. The clamp ring should have an internal diameter of 1.20 inches. For proper operation, the machine must be stopped at the instant of rupture in order to avoid additional application of pressure and load on the specimen.
Briefly, the specimen is clamped by a ring over a thin flexible rubber diaphragm which itself is clamped over a circular hole in the upper face of a reservoir. The liquid used may be water or glycerin. The pressure in the liquid is increased, by values or screw-driven position. Due to increase in the pressure, the diaphragm bulges, taking with it the specimen. At some point the fabric bursts and the pressure at that point is indicated by the pressure gauge.
Since the rubber diaphragm requires a certain pressure to stretch it, corrections are made by doing a blank test, i.e. noting the pressure required to distend the diaphragm the same amount without the presence of same fabric.
In the test specimen, if cuts by chisel for ½ inch are made (either in warp or in weft direction or in both) or if a ¼ inch hole is punched and then the same test is carried out, then it is called as wounded bursting strength test.
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