ASTM D380-94(R2020) pdf free download

ASTM D380-94(R2020) pdf free download.Standard Test Methods for Rubber Hose
6. Measurement of Hose
6.1 Length—Determine the length by means of a steel tape or calibrated measuring device. It shall not include the length of fittings except when specifically so requested and recorded. In the case of woven-jacketed rubber-lined hose, or hose with a helical wire reinforcement, determine the length under a 70-kPa (10-psi) internal pressure. 6.2 Outside Diameter and Reinforcement Diameter— Measure the circumference with a flexible tape and determine the diameter by calculation. Use of a pi (π) tape graduated to read the diameter directly is acceptable. On diameters of 25 mm (1 in.) or less, caliper measurements are acceptable when at least two measurements are made approximately 90° apart and the measurements averaged. The measuring device shall be capable of measuring in increments of 0.25 mm (0.01 in.) or less. All diameter measurements shall be made at least 25 mm (1 in.) distance back from the ends of the hose. 6.3 Inside Diameter—On hose up to and including nominal inside diameter of 75 mm (3 in.) suitable expanding ball gauges, telescoping gauges, or cylindrical-plug gauges shall be used.6.3.1.1 Plug gates shall have the maximum increments in diameter as given above and a minimum step length of9.5 mm (0.37 in.). 6.3.1.2 Ball gauges and telescopic gauges shall be capable of measuring increments of 0.50 mm (0.02 in.) or less. 6.3.2 On hose 150 mm (6 in.) or larger in nominal inside diameter, in addition to inside calipers, a graduated steel scale can be used. On hose 150 mm (6 in.) or larger the measuring device shall be capable of measuring 0.50 mm (0.02 in.) or less. With the exception ofcylindrical plug gauges, at least two measurements shall be made approximately 90° apart and these measurements averaged. For hose that has a visual inside diameter variation at the end of the hose, for example, the flared or necked down end on wire braid reinforced hose, measurements shall be made at least 25 mm (1 in.) distance back from the end of the hose. 6.4 Wall Thickness—Determine the wall thickness at least 12 mm from the end of the hose to avoid flare. Use a micrometer with a rounded anvil in contact with the inside of the hose. Contact surface of the anvil should be about 8 mm long. Support for the anvil should be smaller in diameter than the anvil to avoid inward flare. Care is needed to be sure that the anvil and the foot are square to the surface of the hose. Sufficient force shall be applied to obtain firm contact with, but not indent, hose surface. 6.4.1 The minimum wall thickness shall be the minimum measurement obtained from a series of measurements taken around the circumference of the hose but concentrated in the area visually suspected of being thin. 6.4.2 The maximum wall thickness shall be the maximum measurement obtained from a series of measurements taken around the circumference of the hose but concentrated in the area visually suspected of being thick. 6.4.3 The average wall thickness shall be the average of at least four measurements taken equidistant around the circum- ference of the hose. 6.5 Wall Concentricity—The difference between the mini- mum and maximum wall thickness determined in 6.4.1 and 6.4.2.
7. Thickness of Tube, Cover or Other Rubber Elements
7.1 Determine the thickness of a rubber element from any type of hose in accordance with Method A of Practice D3767. 7.2 Take the thickness of a rubber element adjoining a braid- or helical-wound reinforcing member of any material as the average between two measurements of thickness, one of which shall be obtained using the unbuffed specimen and the other using a specimen that is buffed just sufficiently to remove the braid or helical corrugations. 7.3 Take the thickness of a rubber element adjoining a seamless woven jacket of any material on a specimen that is buffed just sufficiently to remove the corrugations caused by the woven jacket. Where backing is used on a rubber element, remove the backing before measuring thickness. 7.4 Determine the thickness of a rubber element adjoining flexible metal convoluted lining at the valleys formed by the tops of the metal convolutions. Prepare the opposite side of the rubber element, adjacent to other reinforcing members, for thickness measurement as specified in the other paragraphs of this section, depending on the type of reinforcing member. 7.5 Determine the thickness of a rubber element adjoining reinforcing fabric woven prior to assembly in the hose on a specimen that is unbuffed.