The UNIRAPID series fittings are designed for mixed metal-plastic connections in water distribution systems made of plastic pipe with a standardized outer diameter (polyethylene, PVC, nylon, Moplen, etc.).
The hydraulic seal is ensured by the presence of two gaskets: an O-ring and a collar gasket. The use of the double gasket guarantees a hydraulic seal both outward and inward, thereby preventing the possibility of water contamination by other substances present in the soil.
Mechanical sealing is ensured by a self-tightening conical metal ring, featuring an internal annular groove with three teeth and a triangular cross-section that grips the pipe, and secured by a ring-tightening nut. The presence of the conical brass ring ensures mechanical resistance to disengagement in all cases, since the very force that tends to pull the pipe out causes, thanks to the conical mating between the ring nut and the ring, compression on the pipe, which is automatically locked in place with absolute security even in the presence of pressure surges in the line (water hammer).
The pipe-fitting connection is both extremely practical and flexible, as the two components are free to rotate relative to one another, allowing for alignment at all times and, in the case of straight fittings, the connection of the fitting to other branches—a feature exclusive to our fittings.
The male thread on our fittings is conical, not cylindrical, in compliance with the UNI ISO 7 standard. It is clear that a conical thread provides a greater guarantee of sealing compared to a cylindrical one; in fact, major water distribution companies typically require it. In addition, small notches (knurling) are present on the thread crest to ensure that Teflon or other materials suitable for sealing the thread have better adhesion.
The female thread on our fittings is cylindrical, in compliance with the UNI ISO 228 standard.
The fittings are supplied assembled and ready for use. They are very quick and easy to use, as they require no disassembly or reassembly—simply insert the pipe into the fitting’s seat until it stops. Our fitting requires no tightening by the operator. This feature is very useful when working in branch manholes where working space is very limited.
In addition to saving time during installation, this also prevents an installer from over-tightening the ring-tightening nut, which could place excessive stress on the O-ring or the thread, potentially causing cracks that could eventually lead to failure of the seal or the fitting itself. It is equally possible that the ring could be under-tightened, causing the fitting to leak or come loose. In our case, this risk does not exist because the ring is tightened during the internal assembly process and is designed to prevent any possibility of error during tightening (end-of-travel stop).
The pipe clamp can, however, be removed at any time for maintenance or modifications to the system.
The fitting is heavier than standard fittings available on the market. This indicates greater strength, due to wall thicknesses that have been intentionally increased to prevent breakage at points subjected to pressure or specific external stresses on the pipeline (such as ground subsidence). These wall thicknesses also ensure greater resistance to corrosion and, consequently, a longer service life.
