Railway Catalog

24 RAILWAY TOOLS 800-972-2647 www.stanleyinfrastructure.com Testing a Hydraulic System for Comparison to HTMA Recommendations The objective of this test is to determine how your hydraulic system performance compares with HTMA (Hydraulic Tool Manufacturers Association) recommended hydraulic system performance. To perform these tests, you will need a flow and pressure tester such as our P/N 04182 or P/N 29085 shown below and two thermometers (the P/N 29085 has a built-in thermometer). HTMA recommendations for a hydraulic system operating Type I hydraulic tools: • 5 gpm ± 10% / .5 gpm at 2000 psi measured at the tool inlet. • 200 psi or less return pressure at 5.5 gpm—pressure measured at the tool outlet. • Limit system temperature to 140° F on the hottest expected day. Choosing 100° F as the hottest expected day’s temperature, the hydraulic system must maintain a 40 degree temperature difference, air to oil. For example, if the ambient air temperature is 100° F, then the oil temperature should not exceed 140° F. • To simulate tool-generated heat during operation, HTMA recommends using 3 hp, minimum. A reading of 1030 psi minimum at the flow and pressure tester will achieve the recommended 3 hp, minimum. HTMA recommendations for a hydraulic system operating Type II hydraulic tools: • 8 gpm ± 10% / .8 gpm at 2000 psi measured at the tool inlet. • 200 psi or less return pressure at 8.8 gpm, pressure measured at the tool outlet. • Limit system temperature to 140° F on the hottest expected day. Choosing 100° F as the hottest expected day’s temperature, the hydraulic system must maintain a 40 degree temperature difference, air to oil. For example, if the ambient air temperature is 100° F, then the oil temperature should not exceed 140° F. • To simulate tool-generated heat during operation, HTMA recommends using 5 hp, minimum. A reading of 1100 psi minimum at 8 gpm at the flow and pressure tester will achieve the recommended 5 hp, minimum. Select an open site where the air is relatively calm. Place one thermometer in the oil reservoir to measure the temperature of the circulating oil (surface mounted tank thermometers do not adequately measure the temperature of the bulk system oil). Hang the other thermometer in still air to measure the ambient air temperature. Connect the flow and pressure tester to the tool hoses. Fully open the load valve on the tester. Start up the system (with tool circuit control valve OFF) and warm the hydraulic fluid (if necessary) to a minimum of 50° F. Low temperature and maximum viscosity back pressure test Turn ON the tool circuit control valve. Record oil temperature, ambient air temperature, flow rate, and back pressure. Air: _ ______________ ° F Oil: _ ______________ ° F Flow rate: _ ______________ gpm Back pressure: _ ______________ psi STANLEY P/N 04182 STANLEY P/N 29085 Hydraulic system’s capacity to deliver flow against 2000 psi test Close the load valve to where the pressure gage reads 2000 psi. Record flow rate, back pressure, and oil temperature. Flow rate: _______________ gpm Back pressure: _______________ psi Oil: _______________ ° F System capacity to control temperature test Raise the system temperature to 140° F by adjusting the pressure using the load valve on the flow and pressure tester. If it takes more than 1900 psi to get the system temperature to 140° F, adjust the pressure to stabilize the system temperature at some lower temperature, e.g. 120° F. When the system temperature has remained constant for about 15 minutes, record the flow rate, pressure, back pressure, oil temperature, and air temperature. Flow rate: _______________ gpm Pressure: _______________ psi Back pressure: _______________ psi Air: _______________ ° F Oil: _______________ ° F Calculate the tool load hp cooling capacity for an effective 40 degree temperature difference, air to oil using the following formula. (Pressure – Back pressure) x gpm = hp (horse power) 43 x (Oil temperature – Air Temperature) HYDRUALIC SYSTEM REQUIREMENTS