Guide to Progressive Lubrication Systems

Poor lubrication will reduce the expected lifespan of bearings. The consequences can be financially catastrophic, causing work stoppages as well as costly repairs or replacements. That’s why you need a progressive lubrication system.

Progressive lube systems are designed to provide continuous lubrication at specified points to ensure smooth machine operations. These systems reduce the possibility of machine failure due to component corrosion, high temperatures, extreme shock loading, and the caustic effects of raw chemicals at critical lubrication points.

In this article, we’ll cover the two main configurations of progressive lubrication systems, and what to consider before you purchase one for your facility.

Single-Line Parallel Versus Series Progressive

The two main configurations of progressive lube systems are single-line and series. These two systems differ in their design, installation, monitoring applications, and maintenance. Knowing which system is right for your machinery can reduce production and maintenance costs.

Single-Line Parallel Lube System

This system features a pressurized supply that fills different piston distributors/injectors, each serving as lubrication points. You can easily adjust each injector to deliver the right amount of lubrication with a high degree of accuracy.

With single-line lube systems, the failure of one supply line will not disrupt the system’s operation, but blockages will not be as easily detected. For this reason, single-line parallel lube systems are best for smaller machines. They also require routine inspections to ensure that each lube injector is working properly.

Series Progressive Lubrication Systems

These systems are more complex when compared to single-line systems. They’re ideal for larger applications with many lube points. In a series progressive lube system, a master metering valve (and sometimes an optional secondary metering valve) delivers the lubricant to each machine point in the system. Each flow line is independent and applies a specific amount of lubricant until the end of the network has been reached.

A series progressive lube system is best for machine monitoring, as you can program visual feedback alerts or audio alarms into the system. Continual feedback helps prevent system faults and avoid shutdowns.


Before deciding on a single-line or series progressive lube system, there are a few factors to consider. 

First, a series progressive lubrication system will require more extensive engineering, and the entire system must be considered when adding lube points or adjusting delivery volume. Still, this is the preferred type of system for machinery with multiple lube points, as well as systems that need a fuller range of oils and greases.

Second, you need to consider that one lube point blockage or valve failure in a series progressive lube system will cause a failure in the entire system. When the system’s preset pressure value is exceeded, it won’t deliver lubricant throughout the system. At this point, you would need to use a pressure vent valve to reduce system pressure and allow the main lube line oil to flow back towards the oil tank. The injectors are automatically reset and ready for the next lubrication cycle after system pressure has been relieved.

Next, consider the overall design, requirements, and benefits of each configuration. Some of the benefits of a single-line system include its high-pressure capabilities and wide output range, but it’s harder to detect any blockages in the system. A single-line system also requires a vent valve. 

As we mentioned earlier, a series progressive lube system is great for applications that use a wide array of oil and grease lubricants; this system also offers more customization options in terms of lubrication points. Its high customizability can also be a downside for users, and, as previously mentioned, this system requires more effort to set up. 

Lastly, the most important consideration is the application itself.


Single-line parallel lube systems can deliver lubricant over distances up to 50 meters. For more lube points, you need to carefully consider pressure buildup time and vent time. A series progressive lube system is designed to lubricate the friction points or bearings at more points using master and secondary divider blocks along with automatic pressure relief.

Applications for single-line parallel lube systems include construction machinery, on- and off-road machinery, and forestry machines; series progressive lubrication systems are generally used in harvesters and balers, wind turbine generators, concrete mixers, and material handling equipment.

Learn More About Progressive Lubrication Systems Today

Founded in 1946, DropsA is a leading distributor of both single-line and series progressive lubrication systems. You can view our complete line of products here. If you need help selecting the right lubrication system or would like to request a quote, please fill out our online form, and a team member will be in touch with you shortly.