Monday, October 6, 2014
S is for Size
An effective way to remember this hose selection criterion is to remember the word STAMPED. S T A M P E D: S = Size T = Temperature A = Application M = Material to be Conveyed P = Pressure E = Ends or couplings D = Delivery (volume). The inside diameter of the hose must be adequate to keep pressure loss to a minimum and avoid damage to the hose due to heat generation by excessive turbulence. To determine the replacement hose size, read the layline printing on the side of the original hose. If the original hose layline is painted over or worn off, the original hose must be cut and inside diameter measured for size. NOTE: Before cutting an original hose assembly, measure the overall assembly length and coupling orientation. This measurement will be required to build the replacement assembly or match the hose I.D. to the port size. Hose O.D. should not be used to identify the I.D. of the hose. Different hose constructions will vary with the wall thickness and O.D. The hydraulics industry has adopted a measuring system called Dash Numbers to indicate hose and coupling size. The number which precedes the hose or coupling description is the dash size. This industry standard number denotes hose I.D. in sixteenths of an inch (the exceptions are the SAE100R5, SAE100R14, and refrigerant hoses, where dash sizes denote hose I.D. compared to equivalent tube O.D.).