The standard layout of a single-line total loss lubrication system incorporates a pump and spring-loaded piston distributor, main line (connecting to pump and distributor), and secondary line (connecting to distributor and lube point). Performing as a total loss lubrication system, an oil return line from the lube point to the oil reservoir is unnecessary.

  • Dual-Line: These systems can deliver oil or grease (up to NLGI grade 2) to as many as 1000 lube points; distribution points can be easily added or removed. They can be configured to run either as total loss or circulating oil versions.

Their layout consists of two main lines with their respective secondary lines and fittings, an electrically driven pump with reservoir, dual-line feeders, reversing valve, and control unit.

All the distributors of a system are pressurized at the same time, resulting in low pressure losses, and the reset of the delivery piston is simultaneously the second delivery stroke, which takes place at full pump pressure. This makes the dual-line versions especially suitable for extended systems and more viscous types of grease. Assemblies with or without compressive seals can be specified to accommodate light-and heavy-duty operating conditions.

  • Progressive Feeder: Whether functioning as a total loss or circulating oil system, these are intended for intermittent delivery of lubricant (grease up to NLGI grade 2) and can handle up to several hundred lube points. They offer the capability to provide central monitoring of all feeder outlets at a relatively low cost.

These installations use pneumatically or manually operated, or electrically driven piston pumps. Metered quantities of lubricant are fed progressively in predetermined ratios from master feeders to the lube points, either directly or via a secondary downstream feeder.

The lubricant does not leave the respective feeder until the preceding one has discharged its volume. If a lube point does not accept any lubricant, regardless of the reason, or if a secondary feeder is blocked, the entire lubrication cycle is interrupted. At this point, the system can emit a signal to alert operators to the problem.

Guidelines for Success

Deciding which system is most appropriate will depend on the application and on other parameters, such as the operating conditions, accuracy requirements for lubricant quantities, system geometry (size, dimensions, and symmetry), and monitoring demands, among others.

When planning, installing, and subsequently implementing a centralized lubrication system, these guidelines can help maximize opportunities:

  • Address critical process equipment first.
  • Choose a system compatible with the operating environment.
  • Determine the number of lube points.
  • Choose the proper lubricant for the temperature, speed, and load conditions.
  • Calculate appropriate dispense rates and quantities for the application.
  • Choose the pumps consistent with the type of actuation and capacity of the system.
  • Consider monitoring systems that may be required.
  • Train all operations, maintenance, and production personnel on lubrication basics and the plant's strategy.

Use care when installing, starting up, and maintaining any centralized lubrication system. Give the system the same attention as all other sophisticated equipment on a machine.

Finally, partnering early in the process with an experienced and knowledgeable expert can help fulfill the promise these systems can deliver.

Jerry McLain is business development manager-lubrication for SKF USA Inc., Kulpsville, Pa. He assists in developing and implementing customized machinery and equipment lubrication programs. You can e-mailjerry.mclain@skf.com, telephone 513-248-4335, or visitwww.skfusa.com.