ZZ-H-617 Hose, Rubber, Windshield WiperThis specification covers one type of hose for use as flexible air or vacuum lines on automotive windshield wiper systems.

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ZZ-H-617C

TABLE V.  Rod size and depth of insertion.

4.4.5  Low temperature flexibility.  A 12-inch length of hose of full circumference shall be placed in a cold chamber and conditioned at a temperature of   65   5 °F for 12 hours.  At the end of this period and while maintained at the specified temperature, the hose shall be bent 180   around a mandrel having a diameter of

10 times the maximum outside diameter of the hose.  The hose shall then be bent in the opposite direction and the bending repeated for a total of six bends in each direction within a period of 20 seconds.  The hose shall meet the requirements specified in 3.4.4.

4.4.6  Tensile strength.  The tensile strength of the hose shall be determined in accordance with ASTM D412 using a straight specimen of hose of full circumference that is 12 inches in length.  The speed of the power-actuated grip shall be 1 inch per minute and the load at break shall be recorded.  Requirements shall be as specified in 3.4.5.

4.4.7  Accelerated aging.  One 4-inch length of hose of full circumference and three 12-inch lengths of hose of full circumference shall be tested in accordance with ASTM D573 at a temperature of 212   2 °F for 70 hours.  At the end of the aging interval, the test specimens shall be removed from the aging chamber, cooled to room temperature, and subjected to the applicable test specified in table VI.  Requirements shall be as specified in 3.4.6.

TABLE VI.  Test after aging.

4.4.8  Ozone resistance.  An 18-inch length of hose of full circumference shall be bent around a mandrel, having a diameter of seven times the outside diameter of the hose, and bound with twine or tape where the ends of the hose cross one another.  If the hose collapses when bent around the mandrel, provisions shall be made to support the hose internally.  While on the mandrel, the hose shall be conditioned for

45 minutes in air at room temperature then tested in accordance with ASTM D1149.  The ozone concentration shall be 50   5 parts per hundred million (pphm) by volume and the temperature shall be

100   5 °F.  The test specimen shall be exposed to these conditions for 168 hours.  The outer cover of the hose shall be examined under 9X magnification, ignoring areas immediately adjacent to or within the area covered by the tape or twine.  Requirements shall be as specified in 3.4.7.

5.  PACKAGING

5.1  Packaging requirements.  The preservation, packaging, packing, and marking shall be as specified in the contract or purchase order.

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