There’s a major difference between Shelf life and Service life especially when it concerns lubricants!
No one wants to put expired lubricants into their equipment! This can cause unexpected failures which can lead to unplanned downtime which can continue to spiral down the costly path of unproductivity!
The Shelf life is usually what is stamped by the Manufacturer indicating the length of time the product can remain in its current packaging before being deemed unsuitable for use. These can typically be found on the packaging.
The Service life however is determined by the application and conditions under which the lubricant is being used. Usually, estimated running hours / mileage are given by the equipment manufacturer in the maintenance section of the manual. (Condition monitoring can also be used to determine appropriate service intervals.)
However, how will someone know if the product has deteriorated while still in its original packaging? What should someone typically look for?
Above are some tips for identification of deterioration in lubricants. Take a note of these for the next time you are unsure of the integrity of your lubricants.
How are your lubricants currently stored? Are you storing lubricants under the correct conditions? What conditions affect lubricants?
These questions have come up a dozen times during audits and countless warehouse meetings. To answer these questions, there are five main conditions that can affect lubricants. We have detailed them below along with the effects of these conditions on the lubricant.
Temperature – if incorrect can lead to oxidation. For every 10C rise in temperature above 40C the life of the lubricant is halved.
Light – too much can lead to oxidation especially for light sensitive lubricants such as transformer oils. Hence the reason that most packaging is opaque.
Water – this usually works with additives to cause their depletion or contamination of the product. Water in any lubricant is bad (especially for transformer oils as they are involved in the conduction of electricity.
Particulate contamination – contamination can occur by air borne particles if packaging is left open or if dirty containers/vessels are used to transfer the lubricant from its packaging to the component.
Atmospheric contamination – this affects viscosity and promotes oxidation and can occur if packaging is left open. For instance, if a drum is not properly resealed or capped after usage or the most common practice of leaving the drum open with the drum pump on the inside.
Different types of lubricant degradation
Why is it important to know the types of lubricant degradation? It’s important since it helps us to figure out why or in some instance how, the lubricant degraded! Usually degradation is the change that occurs when the lubricant can no longer execute its five main functions:
the reduction of friction
minimization of wear
distribution of heat
removal of contaminants and
improvement of efficiency.
There are 6 main types of Lubricant Degradation as detailed below. Each type produces various by products which can enable us to understand the reason for the degradation and eliminate that / those reasons.
Here are the 6 main types of Lubricant Degradation:
Quite often when we are correcting or helping companies set up their lubrication storage areas, we get asked a lot of questions regarding colour coding. Ideally, the concept of colour coding is to allow field personnel to easily identify and associate particular lubricants with their applications.
However, like most things in reliability, this can be customized to suit your organization. There are no hard and fast rules of using only yellow to represent hydraulic oils. But, what if we had someone that was colour blind?
Usually, when we start colour coding lubricant storage containers, we include symbols and actual names of the lubricant. This helps to assist personnel in having a 3 point verification system.
First they can verify the colour, then the symbol and of course the name of the lubricant.
Names are crucial! Especially for varying viscosities (such as gear or hydraulic oils). For instance all gear oil would have the same colour and symbol but you wouldn’t want to put an ISO 100 gear oil in a gearbox suited for ISO 680.
Audits usually get people nervous! They are worried about what the auditor may or may not find. When we perform lubrication audits, we’re trying to ensure that your equipment is using exactly what it should to perform efficiently.
Why is that necessary? We’ve found that in most organizations, there may have been a time when the OEM recommended lubricant was not readily available and a substitute was used instead. Once the substitute has been used, it magically becomes the recommended lubricant for the rest of the life of the component.
However, if proper checks were not done initially, then the component could be using the wrong lubricant for most of its life. This can contribute to downtime and replacement of parts before their actual useful life has been reached.
Once, we found a gearbox using an ISO 680 gear oil when it should have used an ISO 320 oil. This gearbox used the wrong oil for 30 years! It greatly impacted the efficiency of the gearbox and they experienced numerous breakdowns throughout its life but they never understood or dared to look at the lubricant.
Always ensure that you have the OEM recommended lubricants for your components!