A simple rule for re-ending hydraulic hose assemblies – Don’t
Published: 07 August, 2014
Following on from last month’s look at the importance of hydraulic hose quality and how certified holders of the British Fluid Power Distributors Association’sApproved Hose Assemblies Mark scheme are dedicated to high standards in hose assembly, this article stresses the importance of avoiding the practice of hose re-ending at all costs.
During British Fluid Power Distributors Association (BFPDA) inspection visits for the Approved Hose Assembly Mark Scheme and discussions with fluid power distributors – to both BFPDA members and non-members alike – quality assurance is an important issue. Producers of hose assemblies continually raise the practice of re-ending hose. The response is to refer to BS EN ISO 4413:2010 Hydraulic Fluid Power – General rules and safety requirements for systems and their components. This standard, which most fluid power machinery manufacturers use in order to achieve a ‘presumption of conformity’ with the Machinery Directive, is nothing if not clear on the subject:
• Clause 188.8.131.52.1 a) states: “hose assemblies shall be constructed from hoses that have NOT been previously used in operation as part of another hose assembly and that fulfil all performance and marking requirements given in appropriate standards.”
In CEN and ISO parlance, the word ‘shall’ is taken as ‘must comply’ – it is non-negotiable. If the ‘shall’ requirements of such a standard are not met, compliance with the standard concerned is not possible.
BS EN ISO 4413:2010 is a ‘transposed, harmonised standard’, which means that the members of the European Union have adopted the standard and have withdrawn any conflicting national standards. If you are supplying fluid power ‘machinery’ in the EU it is very likely indeed that you will have to comply with the requirements of this standard.
Even if the product is intended for export outside the EU, the customer may require compliance with BS EN ISO 4413.
As well as being effectively banned in Europe by BS EN ISO 4413, the practice of re-ending hose also destroys all the hard work that goes into an effective quality assurance programme.
Generally, most reputable distributors refuse to re-end hoses. There are, however, some who display a sign or annotate their invoices with a disclaimer to the effect that, “should the re-ended hose fail they are not responsible, as this is a ‘service’ demanded by their customers”. It is likely that a court will reject any disclaimer as the hose assembly producer stated it was an unacceptable practice but still went ahead and re-ended the hose. In other words, the company who manufacture the hose assembly is liable.
Do not trust your equipment to anyone other than a reputable hose equipment provider; whether the company in question is a member of the BFPA Hose Accreditation Scheme, a holder of the BFPDA Approved Hose Assembly Mark or runs a rigorous and reputable scheme of its own. And, in terms of hose training, make sure the provider’s courses are well-established and highly respected within the hydraulics industry; whether they run their own courses or are authorised agents for the BFPA’s own Hose Foundation, Hose Skills and Hose Integrity, Inspection and Management Training courses. When it comes to hose and fittings, don’t accept anything but equipment of a high quality. After all, when the efficiency of your plant and equipment, as well as the health & safety of your workforce is at stake, only the best product, training and service provision is acceptable. One final reminder, if ever your company is tempted to re-end a failed hose, or ask a service provider to do so on your behalf, DON’T.