Protecting engineers in hydraulic applications

The tremendous work potential of hydraulic equipment is matched by its power to harm operators who are not adequately protected or informed. However, there are many safe practices and new initiatives that can help protect engineers from injury, says Andrew Dawes, Product Manager of Hydraulics at ERIKS.

The powerful forces at work within hydraulic engineering are capable of exerting great strength to manipulate materials in many aggressive applications and, since engineers remain in close proximity to these forces, great care and consideration must be taken to protect the human body from severe injury. Take, for example, the high level of fluid pressure necessary to drive machinery: the most common injuries caused by hydraulic equipment result from pinhole leaks in hydraulic hoses; the pressure is such that a jet of fluid from such as leak can penetrate the skin as easily as a hypodermic needle. The image of the hypodermic needle is not evoked here gratuitously; it is provided as an important note to those new to hydraulic engineering, and a necessary reminder to those experienced in the technology, to take extra care and remember that the familiar, everyday equipment used to carry out their day-to-day work is capable of causing serious injury.

So what should an engineer do if a leak is suspected? In the short term, a useful tip is to ensure that you never run your hand or your finger along the line to feel for leaks. At the very least, when checking for small hydraulic leaks, move an object such as a piece of cardboard or paper across the area in question, rather than naked skin. This piece of advice may sound obvious but it cannot be stressed strongly enough how important are these simple safety measures. It is when engineers are busy on the job and fear that a fault has emerged that they are tempted to forget safety training and place themselves in danger by making quick checks for leaks without adequate protection.

To ensure that all employees are reminded to always keep hands and body well away from hoses and fittings that might eject fluid under high pressure, engineering companies should consider reviewing and strengthening their health and safety schedule, which may involve taking part in established schemes. ERIKS, in conjunction with the British Fluid Power Association (BFPA), has launched a course to instruct engineers in the safe installation and maintenance of hydraulic hose assemblies in the hope to minimise the risk of injuries such as those that can be caused by high pressure fluid. Courses such as this are growing in popularity and helping to protect the users of hydraulic equipment by embedding safety as part of company culture within each engineering industry concerned.

Good maintenance practice can minimise the likelihood of hydraulic equipment failure, thus preventing many potentially dangerous situations from arising in the first place, and preventative maintenance is essential. Even the best hydraulic hose will eventually fail as a result of natural degradation, exhibiting signs of wear such as cracks, blisters and bubbles. If these symptoms are evident, engineers can prevent dangerous instances of high pressure leakage by replacing hose early. An unenlightened attitude, such as the belief that running a component down until it fails completely is the most economical option, is swiftly punished by downtime costs and the far greater human cost of injury. The failure of a hydraulic hose assembly presents a further risk: when hydraulic fluid leaks onto the ground, the result is not only a potentially costly clean-up operation but also a fire hazard, risking the lives of workers and, depending on the application, the public and the surrounding environment.

Maintenance must be scheduled before failure occurs during planned downtime and if there are any suspicions that the previous hose did not serve out its expected lifespan then it is important to review the specification and establish that any replacement is capable of meeting application conditions. A proactive hose replacement programme will address such issues, ensure that a replacement is conveniently arranged during downtime and minimise the safety risk hose failure. Preventative maintenance will include regular inspections for cracked or abraded hose covers and fittings, and kinked, flattened or twisted hose, and follow up with a repair and replacement of these items as soon as possible. It is safer to establish proactive, rather than reactive, maintenance to support safety as well as efficiency and it is crucial that operators make regular checks in all applications but the need is particularly acute in applications such as mining, quarrying and construction, where considerable daily stress is placed upon equipment by the aggressive conditions.

Outside the considerations of day-to-day running, hydraulic safety is being enhanced in other ways, notably as a fundamental part of component and machine design. In the same way that component replacement is cheaper in the long term than running components such as hoses and fittings until they fail, it is also important to install quality components fit for purpose from the outset. Thankfully, the need for safety to be designed integrally is now being supported by legislation and guidelines, including the Pressure Equipment Directive. This directive specifies that machine builders and end users within the EU must be provided with safe hydraulic equipment and components.

Another area in which awareness of safety is growing is skin health. Health and safety failures in hydraulic applications are not always the result of dramatic and instantly recognisable injuries such as those caused by pinhole leaks from high pressure hoses. A less instantly obvious risk of injury is posed by repeated exposure to oils and greases. Happily, this danger to skin health, often arising from poorly assembled equipment, is now being addressed. The main threat to skin health is presented by contact dermatitis, which is, according the Health and Safety Executive (HSE), the cause of 70% of skin conditions reported. This condition can be easily and effectively remedied by the use if appropriate skin care products and the HSE, which has recently been tackling the issue, has also addressed a need to raise awareness and understanding. This has involved reminding employers that paying proper attention to the skincare issue comes under the legal obligation to provide a safe working environment.

So, there are plenty of opportunities for operators and engineers to reinforce safety measures and keep injuries out of hydraulic engineering. A degree of risk will always present itself but, by raising awareness, following guidelines and improving specification, installation and maintenance, we can minimise that risk considerably.