Hydraulic hose - more than meets the eye: Writes Ian Morris, director of the British Fluid Power Association.

Despite its simple appearance, a length of hydraulic hose is a highly sophisticated and operation-critical part of an array of plant and equipment used in industries such as construction, agriculture, manufacturing, engineering and offshore. It is tasked with carrying the flow of high-pressure oil safely and efficiently from a pump to a motor in order for the whole system to function efficiently. Yet some users still expect their hose to perform safely and well regardless of the grade used or how infrequently it is serviced or replaced. Indeed, it is ironic that some companies will willingly source the best motors and pumps available, and then blithely attempt to save money by buying a grade of hose that is less than fit for the task.

Tasks and challenges: In order to further emphasise the importance of sourcing quality hydraulic hose, let’s take a closer look at some of their common daily tasks and the challenges they meet along the way. A hydraulic hose often needs to be able to operate at very high pressure; 500bar is not uncommon and in extreme cases pressures can be far higher. It also needs to be capable of handling extremely high temperatures and shock loads.

And it’s not just a hose’s capability of securely containing high-pressure, high-temperature oil that needs to be a non-negotiable; there is also the importance of hose flexibility. A length of hose should be designed to move as often as the machine moves. Watch any excavator and then try to imagine how many times the hose flexes back and forth as the machine goes about its daily tasks. This frequency of movement not only puts stress on the hose and its construction but also on the fittings at either end – the parts that form the all-important connections to the operating part of the machine. Another point to note is that a hose is often fully or partly exposed and can therefore be subject to damage from physical wear and tear or by the sun and its elements – another reason for sourcing a grade of hose that is capable of standing up to such daily rigours. So, with this level of required physical and operational resilience, it can be appreciated that a hydraulic hose is much more than a simple length of black rubber.

Time for replacement: Nevertheless, even if the user sources a high grade of hydraulic hose, everyday stresses such as the containment of often extremely hot oil at high pressure, frequent movement and exposure to the elements means that hose replacement will be necessary at some stage. And when that time arrives it is important to source a hose of identical or similarly high-grade properties. When new, the manufacturer of the original machine will have calculated the correct specifications for all its parts, including its hydraulic hose. However, come the time for replacement the machine’s owner may not return to the original manufacturer and instead have a hose made by a third-party provider. This in itself is not a problem so long as the same specification of hose is used and so long as the replacement hose is correctly routed; taking into account all the relevant quality and safety standards.

The downtime factor: There is also the question of plant and equipment downtime to bear in mind. When a business is largely reliant on hydraulic machinery to undertake its mission-critical tasks, the last thing it needs is for this equipment to cease functioning to the best of its ability, or to fail to operate entirely in some instances. The expense of lost production could, in many cases, run into many thousands of pounds per day, and, to make matters worse, the reputation of company could be at stake if it ceases to be able to perform efficiently. Therefore, the process of ‘fighting fires’ after the equipment has broken down is something to avoid at all costs, and is another example of the importance of ensuring hose and fittings are compatible, of a high quality and regularly maintained.

Health & safety: Sourcing the right grade of hose is also extremely important from a health & safety perspective. A high-pressure hydraulic oil injection injury is a very serious occurrence and something to be avoided at all costs. It may not happen very often, but when it does it’s not only the injured party whose life can be seriously affected; the whole health & safety regime of the company can be called to account. And if this happens, the question of professional responsibility and accountability at management and board level can also be brought into play.

Education and training: With such hose-related issues in mind, the British Fluid Power Association (BFPA) has established a number of programmes aimed at raising the awareness levels of people who work with hydraulic hose at all levels; from the system designer and field engineer, to the machine operator and the person who makes the hose. The training courses have been designed for two primary reasons; first to raise machine performance levels and further enhance the reputation of hydraulic systems, and secondly to keep operators safe. The BFPA runs both the ‘Foundation Course in Working Safely with Hydraulic Hose and Connectors’, and a practical, workshop-based course titled ‘The BFPA Hose Assembly Skills Training Programme’, which takes the basic Foundation level of knowledge and trains attendees to a fully assessed level of ability in hose assembly techniques. A number of reputable hose equipment and service providers are also licensed to carry out these courses throughout the UK and Ireland. More information can be obtained by contacting the BFPA directly.

Reputable providers: In summary, don’t trust your equipment to anyone other than a reputable hose equipment provider; whether the provider in question is a member of the BFPA Hose Accreditation Scheme or runs a rigorous and reputable scheme of its own. And, in terms of hose training, make sure the provider’s courses are well-established and highly respected within the hydraulics industry; whether they run their own courses or are authorised agents for the BFPA’s own Hose Foundation and Hose Skills courses. When it comes to hose and fittings, don’t accept anything but equipment of a high quality. After all, when the efficiency of your plant and equipment, as well as the health & safety of your workforce is at stake, only the best product, training and service provision is acceptable. One final point, if ever your company is tempted to re-end a failed hose DON’T.