Copyright Goodheart-Willcox Co., Inc. 190 Fluid Power materials from the environment. Additional plies of material are often used between layers to bind them together. A wide variety of hoses are available. This makes selection diffi cult in many situations. Standardizing organizations, such as the Society of Automotive Engi- neers (SAE), provide guidelines that help when com- paring the products. For example, SAE standard J517 includes 16 different hydraulic hose styles and gives dimensional and performance specifi cations covering from braided wire, spiral-wound wire, or textile yarns that are either woven or braided. See Figure 8-14. Sev- eral layers may be used in this section, depending on the pressure rating of the hose. The outer section is a protective layer made from synthetic rubber, thermo- plastic, or woven textile materials impregnated with rubber or thermoplastic. This outer material is for- mulated to resist the abuse of weather, abrasive dirt, and the chemical action of the system fl uid or other Hose Used with permission of CNH America LLC Figure 8-13. Flexible hydraulic hose is extensively used when fluid must be transmitted to actuators on movable machine members.