Understanding Centralized Lubrication
Maintaining properly lubricated machinery is an important part of any lubrication program. Without administering lubricant at correct intervals with the proper amount, a machine can experience costly failures. Centralized lubrication systems are a common tool used in industry to distribute a precise amount of lubricant to specific locations at specific times through the use of programmable timers, lubricant pumps and lubricant injectors.
Centralized lubrication systems were introduced in the mid-1930s. Since then, much research has concentrated on resolving the flow issues of viscous lubricants, such as grease, to deliver the fluid properly to its designated points. Advancements in technology have created today's centralized lubrication systems with precise delivery methods for a wide range of industrial applications. Centralized lubrication systems are sometimes referred to as automatic lubrication systems because they are completely or mostly computerized in the process of lubricant dispensing. These systems eliminate the risk of human error and increase precision when an application requires the lubrication of many components on numerous machines.
Centralized lubrication can deliver either grease or oil to a lubrication point. The basic operation of a centralized system includes the following: The system controller and injectors are preset to deliver a specific amount of lubricant at a specific interval. To deliver the lubricant, the lubricant pump is activated by the controller, via an air solenoid. This builds pressure in the lines, causing the grease to flow out of the injectors. A pressure switch is incorporated in the system to deactivate the pump once the lubricant injection is complete. In the last step of this process, the system directs any lubricant remaining in the lines back into the reservoir by venting.
Technological advancements have created many products for controlling and monitoring centralized lubrication systems that further increase the precision and reliability of these systems. Lubricant injectors, system plumbing and lubricant reservoirs are commonly monitored by alarms. An alert signal is sent when an undesirable flow pattern exists or when the lubricant reservoir is low. Incorporating such alarms into a system is useful in preventive maintenance. Furthermore, to prolong maintenance intervals, high-capacity lubricant reservoirs can be incorporated into the systems and typically hold double the volume of the common system reservoir.
Derek Destefano and Nguyen Truong, Noria Corporation, "Selecting Centralized Lubrication Systems". Machinery Lubrication Magazine. November 2007.