The grandfather of all centralized lubrication systems, the Single Line Resistance (SLR) type is a fully engineered system designed to pump oil manually in a single-shot (total loss) method, in an automated cyclical (total loss) manner or in a continuous (recirculative) manner.This low-pressure design delivers an apportioned amount of lubricant to every bearing point when the pump is operated, and can be engineered to accommodate up to 200 delivery points in a single pump system.
Today, the SLR is one of the most widely available lube systems in the marketplace. Originally developed for automotive applications, it was adapted for small to medium machine tools and manufacturing equipment. Introduced to industry in 1923, the system was a U.S. design from Joseph Bijur of the Bijur Lubricating Corp. (now Bijur-Delimon).
How This System Works
The Pros & Cons
On one hand, the SLR system is a simple, inexpensive, engineered lubrication solution designed for small- to medium-sized machinery. On the other hand, these types of systems are only good for use with oil—and they do not produce control signals.
Because the SLR system’s metering units are piped in series (hence the single-line designation), care must be taken to ensure all fittings are leakproof/don’t leak and that meter or control units are never allowed to be “drilled” out to increase the rate of flow, which would have the same effect as a broken line. In such a situation, oil takes the path of least resistance and effectively “starves” all bearings simultaneously.
The pros and cons of a Single Line Resistance lubrication delivery system boil down to this: With basic care and understanding, your SLRs will provide excellent bearing lifecycle management at a minimal cost.
In the next issue, we’ll feature Positive Displacement Injector (PDI) centralized lubrication delivery systems. LMT
For more details on centralized lubrication systems, see Ken Bannister’s book, Lubrication For Industry, published by Industrial Press, or contact him directly. Telephone: (519) 469-9173; e-mail:
Originally developed by Bijur (Bijur-Delimon)
Also offered by Lube, Chiba, Dropsa, Tecalamit, Beka and Trico