centralized or automatic lubrications system

Understanding Automatic Lubrication system

An Automatic Lubrication System (ALS), also known as a centralized lubrication system, is a system that continuously provides a controlled amount of lubricant (either grease or oil) to many spots on a machine while it is running. This technology is more precise, and it eliminates the bearing failure-causing cycle of over-lubrication and under-lubrication. In this article, you’ll learn the definition, functions, diagram, components, types, working, advantages, and disadvantages of an automatic or centralized lubrication system.

A system that needs a human pump or button activation is nevertheless considered a centralized lubrication system even though these systems are typically fully automated. Two categories that share many of the same components can be used to classify the system.


What is an automatic lubrication system?

A system that supplies controlled amounts of lubricant to different spots on a machine while it is running is known as an Automatic Lubrication System (ALS). A system that requires a manual pump or button activation is nevertheless classified as a centralized lubrication system, even if it is normally fully automated. The system can be divided into two categories, each of which has many of the same components.

Automatic lubrication systems with centralized control are an efficient solution to boost machine availability while minimizing dependency on scarce labor. These systems deliver the right amount of lubricant at the right time, reducing friction and wear and extending the life of bearings and machines.

Automatic lubrication systems, which are designed to lubricate individual machines or entire plants, give correct, exact lubricant replenishment to all essential places, enabling a variety of benefits in the process.

centralized or automatic lubrications system


Applying lubricant in small, measured volumes over short and frequent periods is often the most efficient, whether the equipment is fixed, such as in a manufacturing plant, or mobile, such as trucks, mining, or construction equipment. However, due to time and human resource constraints, as well as the physical location or type of equipment, this approach to lubrication is frequently impractical. As a result, the intervals at which machinery is greased are dictated by production cycles, machine availability, and manpower availability, which is not optimal for the point requiring lubrication. To remedy this issue, centralized lubrication systems are put on machines.

Applications of an automatic lubrication system

The applications of automatic or centralized lubrication systems are as follows:

  • Machine tools
  • Automation
  • On/Off-road machines
  • Construction, agriculture, and forestry machines
  • Mining and cement industry
  • Food and beverage
  • Railroad applications
  • Steel industry
  • Pulp and paper
  • Wind energy and more

Components of an automatic lubrication system

The following are the major components of an automatic lubrication system:

  • Control or timer: It triggers the system for lubrication distribution and can be linked to a POS system.
  • Pump with reservoir: The lubricant is stored and delivered to the system via a pump with a reservoir.
  • Injectors and metering valves: It’s a part that measures and distributes lubricant to application spots.
  • Supply lines: it connects the pump to the metering valves or injectors via a pipeline. These valves or injectors are where the lubricant is pumped.
  • Feed lines: A feed line is a pipe that links metering valves or injectors to application sites.

Diagram of a centralized lubrication system:

automatic lubrication system parts

Types of an automatic lubrication system

The following are the various types of automatic lubrication systems:

Single line parallel:

When the volume of a lubricant varies for each location, a single-line parallel system can service a single machine, different zones on a single machine, or even multiple independent machines. In this system, a central pump station automatically distributes lubricant to several injector branches through a single supply line. Each injector is dedicated to a particular lubrication point, operates independently, and can be modified to supply the exact amount of lubricant required.


  • It is easy to design.
  • It is an easy and cost-effective installation.
  • It has individually adjustable injectors.
  • It has a proven dependable design.

Read more: Understanding car oil filter


  • It may not be suitable for combinations of heavy lubricants, cold temperatures, and long supply line runs between pumps and injectors.

Dual-line parallel system:

A dual-line parallel system is similar to a single-line parallel system in that it has two parallel lines. It works by cycling movable valves to distribute measured injections of lubricant using hydraulic pressure. It features two primary supply lines that can be utilized as pressure or vent lines. A two-line system has the advantage of being able to manage hundreds of lubrication sites from a distance of several thousand feet while requiring much smaller tubing or pipe.


  • It easily handles very viscous (heavy) greases.
  • It can accommodate long supply line runs between pump and metering devices.


  • It may not be the most cost-effective for smaller systems.
  • It requires two supply lines (another cost).

Read more: Everything you need to know about automobile cooling fan

Single Line Progressive System:

Individual metering valves and valve assemblies are cycled using lubricant flow in a single-line progressive system. Dispensing pistons move back and forth in a specified bore to operate the valves. To move and displace lubricant, each piston relies on the flow from the previous piston. If one piston does not shift, none of the others will shift either. The output of the valve is not adjustable. When the controller/timer sends a signal to the pump to start the lubrication event, the process begins.

The pump then pumps lubricant into the supply line, which connects to the primary metering valve, for a certain amount of time or a predetermined number of times, as monitored by a piston cycle switch. Lubricant is fed one by one to the many lubrication points using secondary progressive metering valves sized for each series of lubrication points, as well as directly to each point via feed lines.


  • It accommodates a wide range of system control/monitoring options
  • It can identify blockage by monitoring a single point.


  • One blockage can disable the entire system
  • Large systems may require complex piping/tubing runs.

Read more: Understanding Cooling System Hoses

Mist Lubrication:

Mist lubrication, another basic technology, allows for low oil usage and cool bearing operation. Heat and/or air currents produce mist, which is conveyed through the pipe by low-pressure air to the lubricating point. It is then sized to the proper droplet size before being delivered to the bearing. Because the mist is returned to the generator, closed-loop devices are environmentally safe.


  • It cools and lubricates bearings
  • Low pressure keeps pipe material costs down
  • Positive pressure helps keep contaminants out of bearings.


  • Environmental/health concerns of “stray mist,” are especially with open-loop systems
  • It handles oil only
  • It is highly sensitive to flow, viscosity, and pressure variables
  • It has an extra pipe cost for closed-loop systems.

Multi-port Direct Lubrication:

A set of cams will turn and engage separate injectors and DR pump parts to dispense a defined amount of lubricant to each lubrication point when the pump’s controller or an external controller activates the drive motor. Systems are simple to build, have a direct pump to lubrication point without the need for additional attachments, and are simple to troubleshoot.

Working Principle

The working of an automatic lubrication system is less complex and can be easily understood. Although the working varies according to the type, for this article, a single-line parallel automatic lubrication system is being discussed.

When the controller/timer sends a signal to the pump to start the lubrication cycle, the process begins. To build up pressure in the supply line linking the pump to the injectors, the pump starts pumping lubricant. The lube injectors dispense a predetermined amount of lubricant to the lubrication locations through feed lines once the requisite pressure is reached. A pressure switch will transmit a signal to the controller once the entire system reaches the required pressure, signaling that grease has cycled through all distribution points. The pump is turned off. The system’s pressure is released, and grease in the line is redirected back to the pump reservoir until the system’s normal pressure level is restored.

Watch the video below to learn more about the working of a centralized or automatic lubrication system:

For a dual-line parallel system, When the controller/timer delivers a signal to the pump to start the lubricating cycle, the operation begins. The pump starts pumping lubricant to develop pressure in the first (pressure) supply line while venting the second (vent) return line at the same time. Once the required pressure is obtained, the metering devices administer a predefined amount of lubricant via feed lines to half of the lubrication spots.

Advantages of an automatic lubrication system

The following are the benefits of an automatic lubrication system in its various applications.

  1. Regardless of position or accessibility, all important components are lubricated.
  2. Lubrication takes place while the machine is running, distributing the oil evenly throughout the bearing and increasing the machine’s availability.
  3. The safe running of the machinery is ensured by sufficient lubrication of crucial components.
  4. Component wear is decreased, which means longer component life, fewer breakdowns, less downtime, lower replacement expenses, and lower maintenance costs.
  5. No lubricant is wasted because of the precise amount of lubricant delivered.
  6. Safety is improved because there is no climbing around machinery or inaccessible regions (gases, exhaust, restricted spaces, etc.).
  7. Because there is less friction, it consumes less energy.
  8. It boosts overall production by increasing equipment availability and reducing downtime caused by breakdowns or routine maintenance.

Related Article:


An automatic lubrication system is designed to deliver a precise amount of lubricant to an application.  It is also known as a centralized lubrication system and is a system that continuously provides a controlled amount of lubricant (either grease or oil) to many spots on a machine while it is running. That is all for this article, where the definition, functions, diagram, components, types, working, advantages, and disadvantages of automatic lubrication system ALS are discussed. I hope you learn a lot from the lesson, if so, kindly share it with other students. Thanks for reading, see you around!