Hose Master decodes corrugated metal hose: navigating static vs. dynamic MBR

Sudbury International carries corrugated metal hoses by Hose Master.

Sudbury International Engineered Products Limited is Canada’s top source of metal hosing solutions by Hose Master. The manufacturer points out that an important measure of flexibility in corrugated metal hoses is minimum bend radius, or MBR. While most hose constructions list one MBR, these hoses list two kinds – static and dynamic.

Below is how Hose Master explains the substantial differences between static and dynamic MRB, and how customers should use them with these hoses from Sudbury International.

Smallest radius without kinking

According to The Association for Hose and Accessories Distribution, a static MBR is the smallest radius at which one can use a hose without it kinking while bent or flexed into a fixed position. A dynamic MBR is defined as the smallest radius at which the hose is usable while kinking during constant flexing. Customers usually measure the MBR to the centre line of the hose with Hose Master’s corrugated metal hoses.

Although some refer to hose dynamics as the constant or intermittent flexing of an assembly, other application variables should be classified as dynamics, as they can affect assembly cycle life. Dynamics examples include flexing or bending the assembly, vibration, and large pressure swings. If severe dynamics pressures are present, apply extra derating to protect the corrugations from these extreme dynamics.

Most hose applications involve dynamics, so it is generally not a good idea to install a metal hose at its static MBR. Static applications usually happen in installations in which there is some offset in the piping system that is simpler to accommodate with flexible hoses rather than with pipe fittings. The hose is easier to install, and there are fewer connection points.

Hose Master recommends installing a Sudbury International corrugated metal hose in as gentle a bend as possible, even in static applications. If this is unfeasible, the user must understand the allowable radius at which the hose can be installed. Knowing the installed radius in a task allows the use of hose-length calculation formulas to ensure that there is enough hose in the assembly to accommodate movement or offsets.

For more information, contact Sudbury International.

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