Task-Based Training | Refilling a Single-Point Lubricator

Single-point lubricators (SPLs) are designed to supply a precise quantity of grease to a specific point in a machine or piece of equipment slowly over time. These devices come in various types, each suited for different applications and operating mechanisms, and are particularly useful in environments where continuous or periodic lubrication is needed. Common types include spring-activated, gas-operated/electrochemical, battery-operated/electromechanical, motor-driven, and remote single-point lubricators.

Types of Single-Point Lubricators:

1. Spring-Loaded Single-Point Lubricators: Spring-loaded single-point lubricators use a spring mechanism to dispense lubricant. The spring is loaded with the desired amount of lubricant and gradually releases it over time to maintain a constant lubrication level.
2. Positive-Displacement (PD)/Electromechanical Single-Point Lubricators: Electromechanical, or Positive-Displacement, single-point lubricators operate on mechanical principles, utilizing a timer or some other mechanical mechanism to deliver a predefined quantity of lubricant to the application point at specified intervals.
3. Gas-Operated/Electrochemical Single-Point Lubricators: Electrochemical, or gas-operated, single-point lubricators utilize a dial to engage a chemical reaction to produce gas, which then pressurizes the grease and pushes it to the application point. The gas pressure pushes the lubricant from the lubricator to the application point through a dispensing tube.

Why Use a Single-Point Lubricator?

Some applications are hard to get to or unsafe or may require excess grease. Single-point lubricators can provide a more frequent, automated supply of grease over a specified time interval than if you were to apply grease manually.

They require regular inspection and maintenance, as these greasing devices may break or soften due to heat, and the grease-displacement may change due to changes in atmospheric or environmental conditions. Also, the lubricant can go bad and need to be replaced, so it’s important to keep up regular maintenance on your SPLs.

When and How To Refill a Single-Point Lubricator

Single-point lubricators need to be refilled when the lubricant reservoir within the device becomes depleted or nears the end of its dispensing capacity. In most cases, especially in larger-scale applications, SPLs can be refilled directly on the component that needs relubrication. They also come in remote-mounted systems, meaning they are piped away from the component for safe lubrication.

Many newer electromechanical SPLs come equipped with an indicator for when the lubricant level is low and require the (removable) cartridge to be replaced. Most spring-loaded SPLs provide a clear visual window indicating that they need to be refilled and can be connected to a grease gun via hose for easy refilling. Most gas-operated SPLs, on the other hand, are typically programmed to be replaced at an interval and can be easily screwed on and off when refilling.

The specific timing for refilling a single-point lubricator depends on several factors, including:

1. Lubricant Capacity: The capacity of the lubricant reservoir within the single-point lubricator determines how much lubricant it can hold before needing a refill. Manufacturers usually provide information on the reservoir's capacity in terms of volume or time.
2. Lubricant Consumption Rate: The rate at which the machinery at the lubrication point consumes lubricant will determine how frequently the lubricator needs to be refilled. High-usage machinery will deplete the lubricant more quickly and require more frequent refills.
3. Operating Conditions: Harsh operating conditions, such as high temperatures, heavy loads, or dirty environments, may necessitate more frequent lubricant replenishment due to increased wear and lubricant breakdown.
4. Machine Requirements: The machinery being lubricated may have specific requirements for lubricant replenishment based on the manufacturer's recommendations or maintenance schedule.
5. Lubricant Type: Different types of lubricants have varying lifespans and effectiveness. Some lubricants may need more frequent replenishment due to their composition or performance characteristics.

To determine the optimal refill frequency for a single-point lubricator, it's essential to monitor the lubrication point and the lubricant reservoir regularly. Often, lube techs at facilities will be the ones who program the interval at which SPLs need to be refilled. It’s important to keep tabs on these intervals and refill the SPLs as scheduled.

Observing the level of lubricant in the reservoir, following manufacturer recommendations, and conducting routine maintenance checks will help ensure the lubricator is refilled at appropriate intervals to maintain effective lubrication and equipment performance.

Replacing a Single-Point Lubricator Cartridge

Replacing a single-point lubricator cartridge involves a series of steps to ensure a proper and efficient replacement:

1. Safety Precautions: Use appropriate personal protective equipment (PPE) and follow all applicable plant procedures to ensure the machine is in a safe condition to perform the work. If uncertain about any machine safeguards or the work to be performed, consult a supervisor before proceeding.
2. Clean the Cartridge Housing: Clean the cartridge housing to remove any residue or debris from the previous cartridge to ensure it is clean and free of contaminants.
3. Identify the Lubricator Type and Cartridge Size: Determine the specific type and size of the lubricator cartridge that needs replacement to make sure you have a compatible replacement cartridge, and it has the right grease for your part.
4. Access the Lubricator: Locate the single-point lubricator on the machine and ensure it is accessible. Depending on the design, you may need to remove a cover or access panel to reach the cartridge.
5. Release Pressure: If the lubricator is under pressure, release the pressure by loosening the pressure relief valve or purge relief port and clean with a pipe cleaner.
6. Remove the Old Cartridge: Unscrew or unlock the cartridge holder or housing to remove the old cartridge. Carefully pull out the old cartridge from the lubricator.
7. Insert the New Cartridge: Slide the new cartridge into the housing, ensuring it fits securely and properly. Follow any specific instructions provided by the lubricator manufacturer regarding cartridge placement.
8. Secure the Cartridge Holder: Securely screw or lock the cartridge holder or housing in place to secure the new cartridge and set the grease volume delivery according to the right lubrication amount and frequency.
9. Prime the Lubricator: If the SPL has a test function, activate it and check the performance by following the manufacturer's instructions to prime the lubricator and start dispensing the lubricant.
10. Monitor Lubrication Performance: Monitor the lubrication point to ensure the lubricator is dispensing the lubricant properly from the new cartridge.
11. Dispose of Old Cartridge: Properly dispose of the old cartridge in accordance with local regulations and guidelines.
12. Record and Maintain: Keep a record of the lubricant type, amount, and refill date. Establish a regular maintenance schedule to ensure the lubricator functions optimally.

Always refer to the specific manufacturer's instructions and guidelines for the particular single-point lubricator you are working with, as the design and steps for cartridge replacement may vary based on the brand and model.

Key Takeaways:

1. When unscrewing an old lubricator, note any reverse discharge that could indicate a clogged line.
2. On larger lubricators, make sure to mount properly and securely to prevent any breaks, as they tend to be top-heavy.
3. Take all the steps required to stay safe in the field when refilling any lubrication equipment.

This article is based on the “Refilling a Single-Point Lubricator” video from Noria's Task-Based Training series. To purchase this training course, visit the Noria Store.