Chaffing: why should we be concerned?


Heavy equipment isn’t just used to mine gold in the Yukon, extract oil all over the world, or cut trees for the forestry industry; it also helps produce items we use daily. The watch you have on your wrist, the wood framed house you live in, and the plastic reusable cup you had your coffee in this morning are only a few examples. Most of the heavy equipment used for these products require hydraulic oil to operate, a special attention must be paid to ensure that hydraulic hoses are designed, installed and maintained properly to reduce accidents, fires and costly breakdowns.

In order to prevent accidents and costly breakdowns, it is important that all hydraulic hoses are properly routed to ensure chaffing (when a hose becomes worn or abraded from rubbing) does not become an issue. A failure in a hydraulic hose can be catastrophic to production and lead to delays. For example, forestry equipment is usually located in remote and difficult to access areas; if a piece of equipment goes down, it must be repaired quickly, or another piece of equipment must be brought in.

Why are routing of hoses important?

It is important that the design of heavy equipment considers hose routing and that maintenance instructions ensure that hoses are serviced at pre-determined intervals to limit movement and ensure chaffing is not occurring. It is also vital that hydraulic hoses are installed according to the design recommendations.

Why is it important to review installation and maintain hydraulic hoses?

The life of a hydraulic hose can be reduced significantly by installing it near sharp corners, not meeting the minimum bend radius, twisting during installation, using too short of a hose (i.e. not enough slack), or using improper fittings (elbows and adapters). The Society of Automotive Engineers, (SAE) J1273 – Recommended Practices for Hydraulic Hose Assemblies, shows proper installation methods to prevent issues with hydraulic hoses.

As the heavy equipment is used, the opening and closing of valves on the system can cause the hoses to move back and forth a few inches in either direction. If these hoses are improperly routed, the steel braiding can wear on nearby components, leaving only the inner rubber layer to hold high pressure hydraulic oil. This rubber has insufficient strength to handle the pressures it is subject to and can burst. Normally, this would cause a short downtime and require repair; however, a hydraulic oil leak may contaminate the environment and, in the presence of hot components inside the engine compartment (exhaust stack, or turbochargers) can lead to a fire.

The proper design, manufacture and maintenance of heavy equipment is important to reduce hazards associated with hydraulic hoses. Proper maintenance can reduce down time, prevent accidents, and save lives.

If you have any questions or would like to learn more about this topic, please contact our Materials Engineering team at 877 686-0240 or info@cep-experts.ca

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