Storage and handling of lubricants – 9 rules and no errors
Year of publication: 2023
Every day, lubricants ensure the reliable operation and service life of machines and systems around the world. To achieve this, the properties of the various lubricants are precisely matched to the components to be lubricated, the operating conditions and maintenance requirements. Everything could be so simple, but unfortunately it’s not. When storing and handling lubricants alone, errors repeatedly occur and can cause a variety of problems. This can be avoided by proper handling of oils and greases. Nine simple rules help!
The figures from practice illustrate how important careful handling of lubricants is. Studies by renowned experts have shown that 80 % of damage to hydraulic pumps that fail well before their predicted service life is due to deficiencies in maintenance and operation (Totten, G.E.: Handbook of Hydraulic Fluid Technology). Statistics on early failures of rolling bearings tell a similar story.
The numbers may be frightening, but the triggers of the damage are often homemade. The following factors repeatedly play a major role in this:
■ Solid and liquid impurities
■ Mixing of different oil types
■ Exceeded oil-change intervals
■ Use of unsuitable fluids.
On the way to the machine alone, starting with transport, storage or when filling, refilling or topping up in operation, a lubricant can be contaminated in many ways. Premature ageing can also occur.
Most of these shortcomings can be avoided by following simple rules. This article presents the most important of these rules regarding the storage and handling of lubricants. These should cover the entire life cycle of the lubricants in operation and be embedded in a professional lubricant management system in order to have a truly sustainable effect.
1. Lubricant selection
This primarily concerns the technical suitability of the lubricants. This evidence is checked, for example, on the basis of the following criteria:
■ Approvals or lubricant lists of machine or component manufacturers (OEM)
■ ACEA or API classifications (mobile applications)
■ DIN or ISO standards (industrial applications).
In addition to technical suitability, it is important to minimise the number of lubricants and container sizes used. On the one hand, storage space and handling can be simplified. On the other hand, the number of lubricants used also reduces the risk of mix-ups.
Lubricant suppliers should be assessed mainly on the basis of their supply portfolio, delivery times and technical service.
2. Incoming goods inspection
The first step is to check the conformity of the ordered and delivered lubricants based on the complete lubricant designation and the quantity. At the same time, it involves a visual inspection, for example at least for damage to the packaging and containers. It is also very useful to record the delivery documents, batch numbers and results of the visual inspection. When delivering large quantities, for example as loose goods, it is strongly recommended that a reference sample be taken. This can be subjected to a visual inspection at the same time as the sampling.
3. Requirements for storage space
Enclosed, dry premises that are subject to the lowest possible temperature fluctuations are appropriate for storing the lubricants. It makes sense to limit access to the lubricant storage facility to a narrow, trained group of people. This means that not only the incoming goods but also the sampling of lubricants can take place and be documented in a regulated manner. Observance of the legal regulations for the storage of lubricants must of course be taken into account.
The horizontal storage of drums outdoors prevents the ingress of condensate when the two openings made on the upper front side are in the 3 or 9 o'clock position. Alternatively, original sealed drums can also be stored on a clean pallet, upside down.
However, lubricants should only be stored outdoors in exceptional cases. Products such as insulating liquids, refrigerator oils, lubricating greases and aqueous products/concentrates should only be stored indoors.
4. Identification and traceability
Commercial designations of lubricants are often long and often lead to mix-ups in practice. The end user is often unaware that a single letter is crucial in determining whether the lubricant is the right one.
Continuous, easy-to-handle labelling of lubricant containers, transport containers, tools, aids and lubrication points ensures that the correct lubricant actually arrives at the lubrication point.
Depending on the number of lubricants in operation, colour coding can be applied, possibly combined with simple symbols or meaningful abbreviations. In this way, mix-ups and confusions can be avoided as much as possible.
5. Minimise impurities
Not only during storage, but especially when filling, refilling or topping up lubricants, there is a risk of solid or liquid impurities entering the lubricant.
■ Oil storage must be a place of cleanliness
■ Containers must always be stored closed
■ Containers and transport containers must be immediately resealed after opening for sampling or refilling
■ Aids and tools are cleaned regularly and stored appropriately.
When refilling or topping up lubricants in sensitive systems, such as hydraulic systems, recirculating lubrication systems, increasingly also production-critical transmissions, filtration before filling is useful.
6. Avoid overlaps
For classic lubricating oils, the minimum shelf life is usually between two and five years. For certain, very sensitive product groups, such as concentrates for aqueous cooling lubricants, this can also be significantly lower. An appropriate organisation of the storage facility will help to ensure that the shelf life is not exceeded.
The quantity stored should be based on the annual requirement or the planned oil changes. Depending on the delivery time and dynamic distribution of the annual quantity over the different months, a safety buffer should be provided. Consistent compliance with the FIFO principle (First In – First Out) helps to avoid overlaps as much as possible.
7. Tools and aids
The containers, tools and aids used to refill or top up the lubricants should be suitable for the oils or greases and be clean. Simple tools and aids such as drum pumps, oil cans or grease guns should only be used for one lubricant and be marked accordingly. Their appropriate storage prevents the lubricants contained therein from ageing, mixing or becoming contaminated in an impermissible manner.
If more complex tools or aids for different lubricants are used, they must be cleaned and flushed before and after use.
8. Oil change and disposal
After the oil change, the waste oils are temporarily stored in specially approved containers. According to the Waste Oil Ordinance, professional disposal is carried out by accredited specialist companies.
The collection and disposal method are specified on the basis of the waste code number indicated in the safety data sheet of the lubricating oil in accordance with AVV (Waste Register Ordinance). Disposable containers containing oil are disposed of properly in accordance with the German Packaging Act via the Gebinde-Verwertungsgesellschaft der Mineralölwirtschaft mbH.
Simple work instructions and documentation help when it comes to applying the rules safely. Their integration into quality or asset management ensures their application and gradual further development in the best possible way. The economically positive effects are also particularly sustainable.
OELCHECK all-inclusive analyses quickly provide clarity if there is a suspicion of possible contamination, mix-up or confusion of lubricants. They are also an important aid for ensuring quality during incoming goods inspections and for checking the suitability of lubricants for demanding applications.
Take a professional approach to the topic! You will receive support in the introduction or optimisation of sustainable lubricant management in your company in the regularly held OilDoc seminar “Professional Lubricant Management”. Further information & registration: https://en.oildoc.com/oildoc-training/oildoc-training/lubrication-management/
Totten, G.E.: Handbook of Hydraulic Fluid Technology