https://www.trupply.com/pages/grooved-pipe-fittings
Grooved pipe couplings and fittings are used to join and pipes in both wet and dry system. They provided some flexibility in terms of movement and deflection to the piping system. The concept of grooved coupling was invented in 1925 when Victaulic design the first mechanical coupling. Though many other companies make mechanical grooved couplings, grooved coupling are still known mostly as Victualic pipe coupling or Victaulic style pipe fitting.
