Can a 1mm difference in hose wall thickness really reduce the life of a peristaltic pump hose?

pump hoseHoses are the single most important component for the efficiency of a hose pump.

The life of a hose pump drive is directly affected by the quality of the hose that it uses: its construction and especially its surface finish. Here we explain the risk of putting cheaper hoses in your Bredel pumps.

If the wall thickness of the hose fitted into the pump varies by only 1mm, the life of the hose is reduced by at least 25%. But that is not all that suffers, and the results can be expensive maintenance and spare parts.

As the pump hose is occluded between the rotor shoe and the pumphead casing, it is important that the wall thickness is same throughout the hose length. If the hose wall is smaller, it will not be sufficiently compressed (occluded) between the shoe and the pumphead casing and backflow will occur, affecting both efficiency and hose life in a very negative way.

Conversely, hoses with a larger and irregular wall thickness will not fit between the pump casing and the rotor shoe and the resulting forces must be absorbed within the pumphead. The shoe and the rotor are fixed with bearings into the pump casing and do not compensate for the unevenness of the overall hose wall thickness. Hence, fluctuation of the wall thickness generates significant forces on the pumphead bearings, increasing temperature and reducing their life drastically. In the worst case, the bearing housing or the pump housing may also break.

Bredel precision machine the hose outer surface to ensure that the difference in wall thickness between ALL hoses is not more than +/- 0.2 mm of the specified size. Therefore, changing the hose does not require adjustment of the height of the rotor shoe by shimming and both pump performance and hose life will be greater.

If a non-machined hose has a tolerance of +/- 0.5 mm, the change in the force generated by even one additional millimetre is very steep. Tolerance +/- 0.2 mm in wall thickness ensures that the rotor compresses the hose with a force of 4 ... 5 kN, or 4-5 tons. If the tolerance is in the range of +/- 0.5 mm, the resulting force is in the range of 4 ... 16 kN, that is 4 ... 16 tons!

When considering a new hose for your pump, ask yourself if it's important to purchase a cheaper non-machined hose which you may have to change more frequently, with high resulting downtime and greater lubricant costs incurred.

Or, if these benefits of a precision machined Bredel hose outweigh that slightly lower alternative hose cost

 
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