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 grooved joints and these 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.
Our in-house testing on grooved and plain-end pipe using 104.8 mm Type K copper tubing and 50 mm and 200 mm 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 independent testing by Factory Mutual Research Corporation.
When it comes to specifying systems, reliability is a top priority for engineers. Mechanical grooved pipe joining has been a reliable and rugged component of a wide range of mission-critical applications, including data centres and flammable chemical cleaning.
It has also met the rigorous system demands required for high-pressure performance in power applications and in hydraulic lifts.
The method has not only stood the test of time but has been used in some of the most innovative engineering projects in recent years. Among them is the state-of-the-art retractable roof over the centre court at Wimbledon, where grooved technology was selected for the heating and chilled water piping systems in the first project of its type in the world.
Grooved systems are verified by independent approval agencies worldwide, including Factory Mutual Approvals, Lloyd’s Register of Shipping, Loss Prevention Certification Board, Underwriters Laboratories, the American Society of Mechanical Engineers and many more. These are the same agencies that recognise welded, flanged and threaded systems.
Confidence in grooved mechanical piping systems comes from more than 85 years of research and development, exhaustive field observations and extensive independent and manufacturer testing. Properly used and installed, the products are safe and effective.
Engineers can be assured that grooved technology has been robustly tested in the laboratory as well as in the field to demonstrate its consistent 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, as well as by manufacturers.
Fred Matyiku is regional director - northern Europe at Victaulic