A-A-52426 Hose And Hose Assemblies, Non-Metallic, Silicone, Polyester And Wire Reinforced (For Coolant And Heating Systems Of Diesel And Gasoline Powered Engines)This CID covers polyester and wire reinforced, silicone compounded, elastomeric hose and hose assemblies, for coolant and heating systems of diesel and gasoline powered engines, with a temperature range from -40 deg. F to +425 deg. F. All hose types are intended for severe service such as on cars, buses, heavy duty military and commercial trucks, military combat vehicles, and off-road earth moving equipment. Type I (1/2 inch inside diameter (ID) thru 1 1/8 inch ID) hose is intended for connecting hot water heaters to coolant circulating systems of ground vehicles. The hose and hose assemblies described in this CID are hereinafter referred to as "hose".

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A-A-52426A

3.3.6 Resistance to coolant. Hose resistance to coolant shall be as specified in table I when tested in accordance with ASTM D471. Hose shall be immersed in solution of 60 percent inhibited ethylene glycol antifreeze conforming to type I of A-A-52624, and 40 percent water for 166 hours at 235 °F.

3.3.7 Adhesion. Hose construction adhesion shall be as specified in table XI when tested in accordance with ASTM D413.

TABLE XI. Hose adhesion.

3.3.8 Low temperature flexibility. Hose shall evidence no cracks or breaks when tested in accordance with ASTM D380 at a test temperature of -40 °F.

3.3.9 Ozone resistance. Hose shall evidence no cracking or degradation after ozone exposure in accordance with ASTM D1149.

3.3.10 Proof pressure. Hose shall exhibit no leakage during or after proof pressure test in accordance with ASTM D380. Proof pressures shall be one-half the minimum burst pressure values specified in table X.

3.3.11 Pulsating proof pressure. Hose shall not bulge, separate, or leak during or after pulsating proof pressure test in accordance with ASTM D380. The 40 psi internal pressure shall be applied in pulsating cycles of five seconds for 15 minutes total. The five second cycle shall be 2 seconds pressurized and 3 seconds unpressurized.

3.3.12 Resistance to vibration (type III). Hose shall not leak or evidence other damage during or after 50 hours of vibration at 30±5 Hertz and 0.25 inch double amplitude. Water shall be circulated through the hose during vibration at 1/4 of its respective table X burst pressure. Hose up to and including one inch inside diameter shall be installed on the vibration fixture in a manner incorporating a 90 degree bend and a 45 degree circumferential twist. Larger inside diameter hose shall be mounted horizontally with a 45 degree circumferential twist. Each test specimen shall consist of a 24 inch long hose which has been conditioned for 24 hours at 80±9 °F.

3.3.13 Resistance to compression set test. Hose shall meet the compression set requirements of table I after being subjected to compression set test in accordance with ASTM D395, after aging