SK quick-coupling connections provide quick and easy manual coupling of same-type pipes. Disconnection is equally quick and easy. Pipes with these connections are sometimes called Lanninger pipes in reference to agricultural sprinkler inventor and author Karl Ludwig Lanninger. These pipes are normally fabricated in hot-dip galvanised steel with inner diameters up to 300 mm and standard lengths of 6 m.
Pipe sections of this type incorporate a Cardan coupling (also known as a Perrot coupling) – one male and the other female – at each end. The female coupling is equipped with a watertight "O" ring seal. The couplings permit at least 6° angular deflection (i.e. "bending") in any direction of the two connected pipe elements. This is a useful feature for lines laid over uneven ground or with large-radius curves. This capability also permits replacement of individual elements in existing pipelines without requiring lengthwise displacement of the entire line. The system is offered with a wide range of fittings and accessories including elbows, tees, slide valves and transition pieces to other connection systems such as grooved and threaded connections, Storz couplings, flanges, etc.