Some companies run a lot of different hydraulic equipment. Firefighters are one example of a workplace that uses a range of hydraulic equipment, each with its own specification of the type of hydraulic fluid that is indicated for use. Construction, healthcare and agriculture also use a range of different hydraulically powered equipment, from hospital beds to hay balers and everything in between. Being in charge of maintaining all this equipment is a large undertaking, and a common theme for those tasked with keeping everything running is staying on top of the sheer number of different types of hydraulic fluids that are stored and used routinely. There may be very good reasons why a piece of equipment uses a certain type of hydraulic fluid, but sometimes the choice is determined by the past – “we've always used that type of oil so we will continue to do so” – is a common reason behind why different types of oil are used. That, coupled with the fact that some engineers have their own favourite types, can mean that after a few years the stock of hydraulic fluids is running into tens of bottles, all half empty (or full, depending on how you look at things) and taking up valuable storage space. There are some ways you can reduce the number of containers and types of oil you use. Firstly, identify which bottle correlates to which piece of equipment. There may be more than one for very complex equipment. Mark the bottles so you know what hydraulic fluid goes with what. Anything that is unmarked can be discarded, as it is probably not in use anymore. Any bottles that are old or have been open for a long time may have degraded past the point at which they are still useable – the more contact there is between a hydraulic fluid and the air the more degradation will have occurred, so to avoid accidentally using hydraulic fluids that have gone off it is a good idea to regularly discard old containers. The next stage is to identify where the same, or very similar fluids are being used on more than one type of hydraulic equipment. All hydraulic fluids have a viscosity rating, but these are a guideline of the viscosity under normal operating conditions. There is a 10 per cent variation on the viscosity grade, so where there are fluids of, say, 38, 40 and 42 grade then one grade should fulfil the requirements of the three varying grades. Consolidating the same types of fluid into one viscosity grade for all pieces of hydraulic equipment could reduce the number of bottles considerably, and make it much easier for anyone replacing or topping up the fluid levels. It is important when consolidating fluid choices in this way that one refers to the specification of each piece of machinery, to ensure that there are no special reasons why a particular grade of hydraulic fluid is used. Pieces of machinery that experience a lot of fluctuation in operating temperature may require a certain type of hydraulic oil to ensure premium performance throughout operation. When choosing new hydraulic equipment, it is worth considering whether the fluid types indicated by the manufacturer matches what you already have, and whether you are able to use one of the hydraulic fluids you already own if they are a close enough match. By keeping things very simple and reducing the number of hydraulic fluids kept on site you can save money, time and avoid unnecessary cross contamination of fluids within the machinery.