For those who have worked with hydraulics, it should go without saying how important safe operation is. With such high pressures and high fluid temperatures usually involved, any accident can be catastrophic.
Occupational Safety and Health Administration records show dozens of fatalities stemming from hydraulic-related incidents in recent decades. One such case at a food processing plant in North Carolina in 1991 killed 25 workers and injured 56 others. Although several other issues, including locked exits, contributed to the disaster, the fire started when a failed hydraulic line sprayed hydraulic fluid into large gas-fueled cookers.
In other more recent cases:
- An Arkansas employee died in 2018 when repairing a hydraulic leak on an end loader. He drained the hydraulic fluid while working under the bucket, causing the bucket to fall and crush him.
- A California worker died in 2016 when forging parts in a press. A seal failed, releasing flammable fluid onto him at high pressure. The fluid then caught fire.
These instances are the tip of the iceberg. To make sure your shop doesn’t join this list, it’s vital to make sure you always follow the manufacturer’s recommended maintenance schedule and best practices for safe operation. Everyone who is part of your hydraulic program needs to understand the equipment involved, know how to operate it safely and recognize the danger involved if handled carelessly.
A good place to begin is with a periodic inspection of hydraulic components. During normal operation, be aware of how the equipment sounds, looks and feels. Any noticeable difference in its daily operation might indicate a problem.
Always refer to your equipment manufacturer’s inspection recommendations. If they are not available, a good rule of thumb is:
- For mobile equipment: Every 400-600 hours of operation or three months, whichever occurs first.
- For stationary equipment: Every three months.
The following factors influence how often you need to inspect hoses:
- Critical nature of the equipment
- Operating temperatures
- Operating pressures
- Environmental factors
- Type of usage (rugged, abusive, shock, vibration)
- Accessibility of equipment
For example, if you have a rugged, high-pressure hose application operating 24 hours a day, seven days a week, it will require more frequent inspections than a hose used in a mild environment.
In any case, keep an eye out for the three most likely problem areas in hydraulics:
- High heat sources
- Rough abrasion areas
- Tight bends or twists
If an inspection reveals any areas of concern, take the equipment out of service immediately until any problems can be investigated and resolved.
Hydraulic Dangers and Safe Practices
Hydraulic equipment can expose workers and others to multiple hazards, including:
- Pinhole leak injections
- Coupling blowoff/burns from hot fluid
- Hose whipping
- Contact with suddenly moving or falling objects
- Fluid toxicity
Pinhole Leak Injection
A worker might notice a damp, oily, dirty place near a hydraulic line. Not seeing the leak, the person runs a hand or finger along the line to find it. When the pinhole is reached, the fluid can be injected into the skin as if from a hypodermic syringe.
Immediately after the injection, the person experiences only a slight stinging sensation and might not think much about it. Several hours later, however, the wound begins to throb, and severe pain begins. By the time a doctor is seen, it can be too late, and the individual loses a finger, hand or entire arm. Hydraulic oil is a poison bodies cannot process. The only way to remove it is surgically.
Never use your hand to locate a leak. Try a piece of cardboard or similar material instead. If a pinhole leak is encountered or suspected, seek medical attention immediately.
Coupling Blowoff/Burns from Hot Fluid
If a hydraulic assembly fails, the coupling can blow off and hit workers or spray them with hot oil, as in the California case above.
If a fitting comes apart under pressure from the hose, the loose hose can whip around with great force. This can cause serious injury. To prevent this hazard, restrain or shield the hose using clamps or protective shielding.
Contact with Suddenly Moving or Falling Objects
As in the Arkansas example, a hydraulic failure can lead to unexpected movement of equipment or parts, which can be very dangerous.
Hydraulic oil is a petroleum lubricating oil. It is a clear, light-yellow liquid with a mild, bland petroleum odor. When working with or near this material, avoid prolonged breathing of its vapor, mist and fumes, and avoid prolonged or repeated skin contact.
Always use chemical-resistant gloves, splash goggles and an apron, and know the location of the nearest emergency shower and eye wash station.
Wash affected skin, eyes and clothing immediately after contact with hydraulic oil – especially before breaks and meals. Always cleanse skin with a waterless hand cleaner, then wash with soap and water.
Using quality hydraulic equipment is an important step toward avoiding these hazards, as is making sure your team knows how to stay safe.