Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/431954
26 | November - December 2014 | www.machinerylubrication.com THE "LUBE-TIPS" SECTION OF MACHINERY LUBRICATION MAGAZINE FEATURES INNOVATIVE ideas submitted by our readers. Additional tips can be found in our Lube-Tips email newsletter. If you have a tip to share, email it to us at editor@noria.com. To receive the Lube-Tips newsletter, subscribe now at www.MachineryLubrication.com/page/subscriptions. Trending Temperature Rate of Change Consider equipping critical machines with a bearing temperature monitoring system. Most of the time an alarm or a shut- down is triggered at a temperature of 20 to 30 degrees F above the normal operating temperature. When the temperature has exceeded a preset absolute value due to a lubrication malfunction, such as loss of oil, bearing cooling system failure, etc., the alarm may go off, but by that time it is likely too late and damage has already been done. In addition to the above approach, a temperature rate of change (ROC) alarm may be introduced. This allows detection of an abnormal bearing operating condition before the temperature reaches levels that cause irreversible damage. In a nutshell, it works as follows. Temperature is continu- ously measured at a 30-second interval. The temperature gradient in time or ROC is then calculated and compared against a preset ROC alarm value. If all three consecutive gradients have exceeded the preset, an alarm is triggered. The three latest gradients are saved and continuously updated. The oldest one is discarded, and the latest one added if all three requirements are not met. Utilizing this approach, failure can be detected at an early stage of lubrication malfunction. Quick Fix Prevents Messy Error Some gearboxes supplied from the manufacturer have a breather that is basi- cally a pipe plug with a hole drilled in it. If a less experienced craftsman rebuilds a gearbox and switches the drain plug with the breather plug, the result is a messy oil leak. You can replace these orifice breathers on many gearboxes with particulate filter breathers. On gear- boxes with the pipe plug breather, paint the breather plug a different color so it's easy to see. This helps ensure that the plugs are in the correct locations. Keep Oil Containers Clean Lubricant top-up container spouts are sometimes left in the "open" position. Even if the spout design prevents airborne contaminants from entering the oil directly, the end of the spout can allow dust to accumulate inside the lip when in the open position. The oil film inside the lip acts as a magnet for the dust as well. The dust can transfer to the equip- ment during filling or topping off. Use a paint pen to mark "open" and "closed" on the respective posi- tions on the spout. You can also paint the round "stop" that indicates the current position of the spout. This serves as a reminder to operators to close the spout when they are done using the container. Make Maintenance Transparent For a better maintenance program, you can install see-through distribution blocks for your centralized lubrication systems. This makes it easier to track down blockages or leaks that could degrade the life of the equip- ment, thus saving your maintenance budget. New Grease Guns May Not Be Clean Before using a grease gun for the first time, most people clean the coupler and even waste the first couple of pumps of grease to push out any debris. However, they usually do not pay much attention to the inside of the new grease gun. The barrel and rubber plunger can be contaminated with dust, metal filings and other debris from the factory. To prevent contamination, be sure to clean new grease guns before putting them into service for the first time. Why Size Matters for Bearing Lube Lines When running lube lines to out-of- reach bearings, use 3/8-inch-diameter tubing instead of 1/4-inch tubing. The larger opening requires less pressure for your grease gun to push grease through than a smaller opening. You are also less likely to overpressurize the tubing. Before making your final connection to the bear- ings, be sure to purge your line with the specified grease and then connect the fitting to your bearings.