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In 10 years of writing and editing articles for this magazine, the photo choices have never been as gruesome as they were for this article. Fortunately, illustrations of the bodily harm done by a tiny, high-pressure hydraulic leak aren’t suitable for a product development magazine. Most readers don’t need to see the unlucky operator to understand the severity of the injury. Words and phrases like “amputation” and “death from fluid injection” carry enough weight. I don’t need to see the photos, either. I know it looks bad.

The Europeans and Australians understand the dangers, too. Regulations are on the books to govern what OEMs should do to prevent personal injury when a high-pressure hose bursts in close proximity to a human, but it is a safety concern that is still largely overlooked by standards in the United States. It’s known as a line-of-sight burst because anything or anyone directly in front of the hole will be subject to a needle-like stream of oil.

As hydraulic systems become more complex, and pressures and temperatures rise, the potential for an operator or bystander to be exposed to leaks and bursts increases. It’s a danger that companies such as Gates Corp. and Suburban Mfg. are working to eradicate.

While research and meetings continue in the U.S. to create line-of-sight protection standards for the future, there are solutions available now. This is especially important for those OEMs looking to sell product to countries where risk evaluation includes preventing fluid injection.

A failure is not typically due to a poorly made hose. “When you see a hydraulic hose failure, 90% of the time, it is not the fault of the hose. It doesn’t matter what brand of hose it is,” says Yelena Gray, product development engineer, Advanced Materials Group, Gates, Denver, CO. “Installation errors at the factory, the machine’s operational environment, hose application and poor maintenance can all increase a hose’s chance for failure.”

Leak, burst barriers

The LifeGuard hose sleeve system from Gates is a tightly woven inner layer that elongates to absorb the energy of a leak. The sleeving can contain 3,000 psi pinhole leaks at 212 F for up to five minutes. It is also tested for up to 6,000 psi burst containment for added safety. The outer layer restrains the escaping fluid and redirects it to the clamped ends of the hose. A pool of fluid alerts the operator to the failure.

Marty Bauer, product applications engineer, Gates, says that before LifeGuard some customers required that hoses running next to the operator have a sleeve over them. “We used an abrasion sleeve, which we made clear was not designed for line-of-site protection.” The idea was that the sleeve would prevent any rupture, which was believed to be caused by abrasion. Testing has since proven that theory false.

“From a legal stand point, it satisfied the requirements, but it did nothing to protect the operator from a burst or leak,” says Bauer. “The rules are beginning to change, since significant injuries have been occurring in the field due to higher pressures.”

In developing the LifeGuard product, says Gray, “there were no U.S. standards on which to base the tests and product design. We had to develop our own pass-fail criteria based on our experience. We mimicked the applications and failures we saw in the field to design and prove the product.”

Suburban, a diversified manufacturer in Monticello, MN, recently introduced its Diamondback sleeve to give protection from line-of-site bursts. The product is a natural progression from its Sidewinder abrasion sleeving, which has been offered for more than a decade.