TPi November 2021

Selecting the right hydraulic tube-fitting system for marine applications By Gabriella Paranyi, EMEA marketing communication manager, Danfoss Power Solutions When it comes to specifying a hydraulic piping connection system for marine applications there are a number of critical factors to keep in mind. Firstly, the system must carry approval in accordance with the relevant agency specification. Only then can a design engineer begin to scrutinise system capabilities such as reliable, leak-free performance. There is also the issue of the corrosive marine environment, which demands a tubing connection system – and fittings – manufactured from stainless steel. For these reasons, the WALFORMplus ® tube connector system, from Danfoss Power Solutions, is proving increasingly popular across the industry as it answers many of the questions posed by design engineers seeking an optimised solution to their hydraulic piping requirements. provide third-party confirmation that the products meet a wide range of test requirements according to their defined operating pressure. Assuming the system carries the required approval, the design engineer can begin his or her assessment of other selection factors, such as pressure resistance, vibration resistance and safety. For defence applications, designers must also think about the potential for a hydraulic tube-fitting system to retain its functionality after a torpedo strike, for example. Ease-of- installation, soft sealing and resistance to pull-out forces are further considerations. Forming, not cutting A cold-forming technology system such as WALFORMplus is proving particularly popular in comparison with tube-cutting systems. There are many reasons for this trend. For instance, the cold forming of materials increases stress resistance at the most crucial points of the tube. Combined with no sharp ends, this effect creates outstanding vibration resistance. In addition, as a dry, non-cutting forming process, cold forming produces no waste or mess. WALFORMplus represents a reliable, easy-to-install forming system that uses minimal components. The system also provides ultra-high-pressure resistance and the option of a soft seal. Another key factor is process stability, which comes from the machine that forms the tube connection. Any cold tube-forming machine should produce assemblies with the same quality time-after-time, independent of the tolerance influences imparted by the tube or fitting.

Type approvals form the backbone of the marine industry. Originally a requirement of ship insurance companies, many different agencies (with different type approvals) operate in this sector, including DNV GL, Bureau Veritas and ABS, to name only a few. Although the relevant approval usually relates to geographic area, all agencies fall under the umbrella of International Association of Classification Societies (IACS). By fulfilling the type approvals, components used for marine projects are confirming a minimum performance level in terms of mechanical resistance and fatigue life. This performance is required to ensure the functionality of safety-critical systems, as well as behaviour in the event of fire or mechanical exposure. Of course, products that meet the marine sector’s rigorous type approvals can also serve other industries. These approvals

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November 2021 TUBE PRODUCTS INTERNATIONAL