How to Check Lubricant Flow in Centralized Lube Systems

Centralized lubrication systems are designed to deliver suitable volumes of lubricant, either oil or grease, to various locations on a machine at proper frequencies while the equipment is in service. This application method is often employed to remove the possibility of human error, minimize downtime, reduce labor costs and improve employee safety all while enhancing the service life of the equipment.

Although these systems offer several advantages, there are also notable drawbacks, including the possibility of equipment installation and application errors as well as fewer routine inspections of the components. These systems are somewhat automated, but there is still a need to have a basic understanding of each type of system and to perform regular inspections to verify that they are functioning correctly.

A typical centralized system will include a reservoir to contain the lubricant, a pumping station to initiate pressure and flow, flow dividers or a manifold to direct lubricant to the various locations across the equipment, metering valves to regulate the appropriate volume required for each point, and a nozzle to apply the lubricant at the specified locations.

Parallel vs. Series Centralized Systems

To identify and confirm the correct flow in a system, you must understand the workings of the components that make up the system as well as the type of system installed. There generally are two different arrangements of centralized systems: parallel and series. With parallel systems, all the valves function independently of one another. The primary disadvantage of these systems is that if one valve fails, there often is no indication given at the pumping station.

In series systems, all the valves feed off the main distribution line. In this case, if one valve fails to operate, then all the valves will fail to operate. Both systems have their benefits and concerns. Regardless of the system you choose, it should be examined regularly when inspection tasks are performed on the system and components.

Visual Inspections for Proper Flow

To confirm proper flow in a system, you must check the metering valves. These valves should be initially adjusted to provide adequate lubrication to each location. To ensure the right volume is being dispensed, capture a specified amount of lubricant and then extrapolate the feed-rate volume over a short period of time.

Other preventive maintenance tasks that can help minimize flow-related concerns within a centralized lubrication system involve inspecting lines for leaks, kinks or breaks; checking and cleaning filters and strainers; cleaning and replacing metering valves; and examining the system for visible contaminant buildup.

Beyond the component structure, other concerns with centralized lubrication systems include ensuring the right lubricant has been selected, the correct viscosity has been identified, a process is in place to prevent lubricant mixing, and the temperature to which the system and lubricant will be subjected has been considered.