When mechanical and electrical power methods fail to provide a practical power transmission solution, hydraulics and pneumatics—fluid power—deliver. Offering linear and rotary motion with high force and torque with a smaller, lighter package than other forms of power transmission, multitudinous industries depend on fluid power.
The fluid—whether liquid (typically oil) or gas (typically compressed air)—is the lifeblood of the operation, making the hose the veins. As materials and systems that transmit energy via pressurized hydraulic fluids or compressed air while in contact with hundreds of thousands of workers every day, hydraulic hose assemblies need to remain safe and reliable. SAE J 1273-2019: Recommended Practices For Hydraulic Hose Assemblies offers guidelines to assure this.
Dangers of Hydraulics and Hydraulic Hose Assemblies
According to the Occupational Safety and Health Administration (OSHA), several hydraulics-related injuries and fatalities occur each year. Hydraulics is found typically in off-highway equipment and heavy machinery, so these are the main accident areas.
With systems that can operate over 2,000 psi, hydraulic hose systems undergo immense levels of fluid pressure. According to SAE J 1273-2019, excessive pressure is a factor that can accelerate assembly failure. For this reason, hose selection is based on system pressure, along with several related factors, such as suction, external pressure, and permeation.
A myriad of other variables lead to hose and fitting degradation–temperature, electricity, abrasion, paint, ultraviolet light, and saltwater. If a hose stops functioning properly, the results can be quite dangerous.
For example, if a pressurized hose system blows apart, a few prominent hazards can take place. The fittings can be thrown off at high speed, and the loose hose can flail at extreme force. SAE J 1273-2019 refers to this as “whipping hose.” In April 2018, one of these events, occurring while an employee was adjusting the wire length setting on an evaporative air cooler, resulted in a broken ankle.
Fluid injections are another notable hydraulics-related hazard. These events, which take place when fine streams of escaping pressurized fluid penetrate the skin and enter the human body, can lead to severe tissue damage and loss of limb. In September 2017, one such event took place after an employee was replacing a hydraulic valve on a reach stacker. While loosening the hydraulic line, the line blew off and forced hydraulic fluid into the base of his thumb.
In addition to these hazards, conveyed fluids can present dangers associated with burns, fire, and explosions. The fluid passing through the hose can also generate static electricity, which makes static-electric discharge and resulting fires and explosions an area of concern.
SAE J 1273-2019: Recommended Practices For Hydraulic Hose Assemblies
Improper selection, fabrication, installation, or maintenance of fluid power hose assemblies can result in serious injury or property damage. To help address the hazards associated with hydraulic hose systems, SAE J 1273-2019 outlines numerous safety considerations during all phases of design and use. Therefore, the guidance outlined in this document can reduce the risk of injury or damage.
For example, in the event of a fluid injection, SAE J 1273-2019 advises to see a doctor immediately and not to delay or treat as a simple cut, along with further key considerations.
Ultimately, SAE J 1273-2019 provides guidelines for the selection, routing, fabrication, installation, replacement, maintenance, and storage of hose and hose assemblies for hydraulic fluid-power systems. As noted in the scope, many of these recommended practices also may be suitable for other hoses and systems.
Who Can Use SAE J 1273-2019?
Since fluid power systems are complex and need extensive knowledge of hose systems, all-inclusive, step-by-step instructions are not practical and fall beyond the scope of SAE J 1273-2019. Instead, it is intended to be a guide for users, who may fall in various skill levels.
For those new to hose use in fluid-power systems, SAE J 1273-2019 outlines practices to note during each phase of design and use. For more-experienced designers, these considerations can help achieve proper results. Less experienced users who need more information can consult specialists such as suppliers and manufacturers.
SAE J 1273-2019: Recommended Practices For Hydraulic Hose Assemblies is available on the ANSI Webstore.
Referenced Documents in SAE J 1273
The following SAE and ISO standards are referenced in the SAE J 1273-2019 document and can aid compliance and safety efforts to those who work with hydraulic hose assemblies: