Use of Non-Genuine Parts

Why Using Non-Genuine Spider Inserts Can Harm Your System Nobody likes an imposter, especially when it comes to replacement of mechanical components, such flexible jaw couplings like KTR’s ROTEX®. Products that are made or selected by the manufacturer are considered ‘genuine’ as they undergo vigorous testing to ensure quality, safety, and how they impact the overall performance. Yet despite our greatest efforts sometimes these genuine parts fail, which is precisely why we offer warranties. When warranties expire or other factors come into play, such as availability, operators sometimes choose to replace genuine parts with a non-genuine substitute. A non-genuine part may be visually and even mechanically similar to its genuine counterpart but cannot guarantee the same level of quality and safety as it has not undergone the same testing. Aside from performance problems, utilizing non-genuine parts can also invalidate the warranties and certification of the coupling and system itself. The overall performance and safety of complex and expensive operating systems are entirely dependent upon the quality of its constituent parts. As such, using sub-par and/or disingenuous parts can lead to detrimental results and this is especially true when it comes to spider inserts (elastomer elements) for jaw-type couplings. Anyone who has selected a jaw-type coupling knows that it is a complicated process with many variables to take into consideration. Therefore, it should come as no surprise that the same type of consideration must be taken when selecting a replacement spider. At KTR, our ROTEX couplings come standard with a poly-elastomer material (T-Pur). This material has improved fatigue strength and a 35% greater temperature resistance than our previous standard elastomers. This means T-PUR spiders can withstand temperatures ranging from -50 to +120 °C (+150 °C short term max.), compared to the previous standard range of -30 to +90 °C (+120 °C short term max.). On this specification alone, it’s easy to see how selecting a non-genuine part with a lower temperature range could lead to damage if selected for a system that operates beyond it. Of course, there are a number of other important factors to consider besides temperature allowances when selecting a spider element replacement. Shore hardness is critical to a system’s performance, which is why choosing a spider insert with even a slightly different shore hardness can affect performance, wear, and durability. Although many manufacturers (including ourselves) use colours to denote various shore hardness, there is no universal colour code. Therefore, it’s not as simple as swapping an orange T-PUR element for an orange element from another manufacturer. Fit is also very important to performance characteristics and wear of the coupling. General dimensions of jaw coupling spiders, and metallic hubs, can also appear very similar. However small discrepancies in manufacturing tolerances will mean that mixing alternate brand components will likely result in unwanted wear points, with possible further affect as to how the coupling handles misalignment. Note that a standard spider element should also not be replaced with a back-lash free coupling spider, and vice versa, as fit and performance will be significantly compromised, even if it’s of the same brand. It’s always a good practice to question why you are in need of a replacement in the first place. Was the coupling improperly selected? Is there an alignment issue? These are critical questions that need to be asked. At KTR, we’re always here to provide any assistance or guidance you may require. All things considered, using a non-genuine part just isn’t worth the headache, regardless of its price. Quality and fit are key – and that’s something you just can’t fake.

For more information on Use of Non-Genuine Parts talk to KTR U.K. Ltd