TPi January 2013

Cut grooving removes less metal, to less depth, than threading, thus maintaining pipe integrity

material changes are comparable to any other cold-forming manufacturing operations.

Flow dynamics The inside protrusion of a roll groove is small and smooth at its entry and exit and has been proven to have negligible effect on both flow and/or line pressure. Published ratings take into account the groove and, through testing on the performance of a joint, pressure ratings with a three to one safety factor are evaluated. Recent flow testing was conducted on roll-grooved joints, and these tests confirmed excellent flow characteristics, with an insignificant contribution to system pressure loss. In fact, the amount was negligible in comparison with more common points of flow loss, such as pipe friction, valves, bends and branches. Victaulic in-house testing on grooved- and plain-end pipe using 104.8mm Type “K” copper tubing and 50mm and 200mm Schedule 10 and Schedule 40 carbon steel pipe saw pressure drops measured with velocities between 4-20 metres per second at ambient water temperature. The results proved that pressure loss was negligible. These findings are also supported through rigorous independent testing by Factory Mutual Research Corporation, further attesting to the low flow loss characteristics of grooved joints. Proven reliability When it comes to specification of systems, reliability is an over-riding criterion. Mechanical grooved pipe joining has proved its reliability in many landmark buildings and projects throughout the world over the years. More recently it was selected as the preferred method at the All England Lawn Tennis Club centre court at Wimbledon, where Victaulic is used in the world’s first tournament court retractable roof.

Grooved piping systems have a union at every joint for flexibility and ease of maintenance

Moreover, mechanical joining has been a reliable and rugged component of mission-critical applications such as data centres, flammable chemical cleaning applications, the rigorous system demands required for high-pressure applications in power applications and in hydraulic elevators. The benefits of grooving are verified by independent approval agencies worldwide including Bureau Veritas (BV), Det Norske Veritas (DNV), Deutsche Vereingung des Gas- und Wasserfaches eV (DVGW), Factory Mutual Approvals (FM), Lloyd’s Register of Shipping, Loss Prevention Certification Board Ltd (LPCB), Underwriters Laboratories, Inc (UL), Verband der Schandenverhütung (VdS), Vereinigung Kantonaler Feuerversicherungen (VKF), American Society of Mechanical Engineers (ASME), and many more. These are the same agencies that recognise welded, flanged and threaded systems. Victaulic stakes its reputation on the safety of its products when properly used and installed. The company’s confidence in grooved mechanical piping systems comes from more than 85 years of research and design, exhaustive field observations, and extensive independent and in-company testing. Conclusion Engineers can be assured that grooved technology has been robustly tested by research and development engineers in the lab as well as in the field to consistently demonstrate its strength and reliability. Details about the grooving process, the strength of grooved pipe, and flow characteristics are further explained in published reports from independent agencies and other manufacturers.

Coupling housings engage the groove and encase a pressure responsive gasket that creates a seal unified joint

Victaulic – USA www.victaulic.com

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Tube Products International January 2013

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