Fire extinguishing systems are manufactured and installed with pipes and fittings that can be threaded, welded, flanged, or a combination of them. At present, the grooved method is being applied with greater frequency, both in pipes and accessories, for the manufacture and installation of fire extinguishing systems, respectively.
Grooved systems use grooved fittings that come from the factory with this feature, and the pipes are grooved at their ends to join these fittings. The grooving machine is the equipment used to make these grooves in the pipes.
Grooved methods are used for any pipe diameter, it is efficient and clean, both in manufacturing and installation. The grooved systems are manufactured outside the areas where they are to be installed (whether they are productive or empty areas) and are installed with the use of combination wrenches only. The grooving of the pipe consists of the deformation of the tube to generate a channel in it, while in the threading of the tube material is removed to generate the thread.
The grooved coupling or joint is the joint fitting of grooved pipes and grooved fittings (elbows, tees, reductions). This type of union is approved by NFPA 13 Standards.
Grooved couplings and accessories must be ULFM (Underwriters Laboratories and Factory Mutual Engineering Corp.) listed and approved for fire protection services.
Source: Vicente Andrade