3 Main Interlocked Failure Modes

By: Erik Kane | On: May 4, 2017

Albert Einstein famously said, “The only source of knowledge is experience.” And when it comes to knowledge with metal hose, Hose Master has pioneered solutions through application experience since 1982. Interlocked metal hose is our legacy product line, and has been continuously produced and innovated at Hose Master since the company’s inception. During that time, we’ve seen hoses both excel in the field, as well as fail from all sorts of factors (misapplication, misuse, fatigue, etc.) but the majority of interlocked hose failure can be attributed to one of three failure modes: torque, abrasion, and overbending.

Torque is without a doubt the number-one killer of interlocked hoses. In any sort of piping installation, torque is a force to be reckoned with and can wreak havoc on any of the components in the system. But this is especially true with interlocked hose due to its construction. The shaping process that is performed on the strip makes it able to interlock onto itself, and is what gives the hose its ability to flex. But when an interlocked hose is torqued it begins to ‘unwind’ which loosens the interlocked profile and increases leakage and a possible unravelling of the hose. Torqueing the hose is a common problem because it is often a direct result of mishandling the hose in its application. Preventing torque is primarily an issue of knowing how to handle the hose properly. If a hose has been known to fail from torque consistently, or will see excessive handling, manufacturers often offer varying options on interlocked hoses to help combat torque and make the hose more resilient.

Abrasion is another common killer of interlocked metal hose. Because these hoses are not completely air-tight, the application rarely calls for gases or liquids, and is usually some sort of particulate. Powders, pellets, granules, and aggregate materials are all commonly transferred in interlocked metal hoses, and these media types are commonly abrasive. Their degree of abrasiveness depends both on the media type, and the speed at which it’s traveling through the hose, and can end up being a problem. Metal hoses have a relatively smooth, hard interior which allows the material to move through at a higher speed than other hose materials. In the case of finer media, this can result in a “sandblasting” effect that can rapidly wear through the walls of the hose. The best way to combat excessive abrasion is to make sure there are no extreme bends in the hose and to make sure the hose construction is compatible with the media type. Adding a liner or using a heavier gauge of material are both good options for making the hose more robust.

Overbending is the third most common failure mode we see with interlocked hoses, and is a common concern for all hoses. While interlocked hose is very rugged by comparison, once it becomes truly overbent, it is much less-forgiving than most other hose types. Because the hose’s ability to flex comes from its interlocked profile, the flexing ability is mechanical (i.e. the metal strips sliding against each other) as opposed to the material stretching as it does with rubber or plastic hoses. If the hose is forced to bend beyond its capabilities, the metal profile becomes bent and distorted, and will not return to its original shape. This will affect the hose’s ability to flex and transfer media, and can also lead to a loss of interlock. Luckily, because interlocked hoses are rugged, you don’t have to guess where it’s bending limits are. In fact, interlocked hose is often used as an external guard to protect other types of hoses from being over-bent. So if the hose is being flexed to a point where it stops and the corrugations are touching each other, don’t continue to push the hose past its limits or the damage will be irreversible.

Knowing these interlocked hose failure modes can help prevent them in an application, and if identified early on, can be addressed in the hose’s construction before it ever sees service. Hose Master’s dedicated sales team has the tools and experience to diagnose your hose applications and configure the right product for you. For additional information, *click here* to access Hose Master’s interlocked metal hose catalog, or contact us at 216-481-2020 or insidesales@hosemaster.com and we would be happy to assist you.


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