Pit & Quarry, March 2015

PIT STOP knowledge of both temperatures is necessary to provide the longest life possible Application considerations How will the hose be used Will it be static like a pipeline or will it be flexing regularly as a dredge hose might Application conditions tell a hose engineer what kind of materials should be specified to provide the best hose construction for the particular conditions The material being transported is a key determinant in selecting the most suitable tube for a hose A hose that is conveying highly abrasive coarse aggregate slurry requires a different tube material than one for very fine aggregate slurry A dry material also requires a tube with a higher durometer rating to defend against the high rate of wear that these types of materials often generate Specific gravity velocity particle size moisture content and chemical composition are among several factors that provide a hose engineer the necessary information for selecting the best tube material for optimum life Pressure ratings Hose working pressure is generally rated in pounds per square inch PSI An operation should know the working pressure of Class 150 Flange Template B16 Pressure Ratings Spec Material Pressure PSI Temp F B165 Var Carbon Steels 235 290 100 B165 Var Nickel Alloys 90 290 100 B165 Var Carbon Steels 140 600 B165 Var Nickel Alloys 85 140 600 B1642 Ductile Iron 250 100 B1642 Ductile Iron 140 600 ANSI Flange Class Temperature F 150 300 100 290 psi 740 psi 200 260 psi 675 psi the system as well as any potential pressure spikes the system could be susceptible to Hoses should be manufactured and tested to withstand maximum surge pressure In other words compensation for pressure surges spikes or jumps should be taken into consideration and should not exceed a hoses maximum working pressure Failure to select a hose that meets this criterion could lead to end blow offs hose leakage and hose bursts Hose assemblies are usually built with a safety factor of 3 to 1 or 4 to 1 based on working pressure and or industry standards Hose manufacturers should periodically pressure test hose assemblies to one and a half times their working pressure during the manufacturing process to ensure they are maintaining quality construction compliance In addition vacuum conditions should also be reviewed If a hose cannot pull the correct vacuum performance will decrease and potentially lead to damage of both the pump and the system Ends flanges fittings clamps and couplings Selecting the correct ends for a mine slurry hose assembly goes far beyond the desire for ease of installation All of the factors discussed above should be taken into consideration in order to select the best end for each hose assembly All flanges are designated to a particular class based on the flanges composition such as cast iron or steel and the type of threaded material used for the fittings Based on the class ratings there are several characteristics such as pressure temperature ratings bolt and nut dimensions coating materials and other factors that create the standards For most mining and material handling applications hose assemblies use an ANSI American National Standards Institute class flange The table above shows typical ANSI class flanges and their ratings for mining and material handling Note There often is confusion that an ANSI class 150 flange is rated to 150 PSI This is not the case Based on B165 carbon steel an ANSI class 150 flange may be used on a THE LATEST SCALES FOR WHEEL LOADERS EXCAVATORS WEIGHLOG VUE Easy to Use 7 Color Touchscreen Wheel Loader Scale and Reverse Camera See your accumulated loads target loads customer name material and more Save Load Data to SD Card USB Memory Wireless and WiFi Compatible Full Featured Scale for any Operation JOIN US AT BOOTH 1368 www loupelectronics com or call 877 489 5687 90 PIT QUARRY March 2015 www pitandquarry com