Polymer replaces steel in hydraulic coupling system

The couplings are mainly used to rapidly connect and disconnect the hydraulic lines between a tractor and equipment such as trailers and ploughs, without the need to use any tools. The polymer, manufactured by Victrex Polymer Solutions, has made it possible for Parker to offer compact rigid couplings. The company replaced several steel components in its RSD quick couplings with a single injection moulded component made of Victrex Peek polymer. The new coupling can be used under extreme conditions such as high temperatures while maintaining its elasticity. David Aragones, project manager for Parker Hannifin, said the technology behind the RSD couplings allows a completely safe connection of a male connector, whether pressurised or not, even under adverse conditions. The couplings can be operated under a maximum pressure of 250bar and withstand a return flow rate that may reach 190l/min and beyond for a few seconds at a temperature close to 120^°C. Aragones said: "Apart from the high performance demanded of the coupling, it was essential for us to control our production costs by reducing the number of metal components. Consequently, we sought a multipurpose material that was both highly flexible and capable of withstanding high loads over a wide range of temperatures in order to allow us to incorporate as many functions as possible in the clip." Parker Hannifin says it has met these requirements by choosing the polymer for this new range of hydraulic couplings. According to the company, the clip made from Victrix Peek, minimises the number of components in motion during connection and disconnection significantly improving the safety of the system as well as its reliability. Parker Hannifin claims that the shape of the clip combined with the elasticity and the fatigue resistance of the polymer ensures a reliable and durable connection of the pressurised male connector. Aragones continued: "Use of this high performance plastic has allowed us to offer an entirely innovative, patented design. Consequently, these connectors are particularly valued for their pressure resistant characteristics and their compactness." Didier Padey, market development manager for Victrex Europe, added: "Victrex Peek polymer retains its mechanical properties even in aggressive environments at high temperatures. Apart from its outstanding thermal performance, Victrex Peek presents a unique combination of properties. In this case, it is particularly its mechanical resistance and ductility, even under the most adverse conditions that led to specification of Victrex Peek polymer for the valve clip of the RSD hydraulic couplings from Parker. "The unique combination of its properties enabled VICTREX PEEK polymer to be successfully substituted for several traditional materials, incorporating several functions in a single component and thereby reduce the number of components to be assembled and control the overall cost of the product." Thanks to the cooperation between Parker Hannafin the designer of the valve clips, Victrex the producer of the material and VP PLAST the company subcontracted to manufacture the component, Parker was able to achieve its aims with increased design freedom and simplified implementation through the use of injection molding, while improving the functions of its RSD coupling.