The SESTA expansion ring system, based on expansion ring technology, for the conduction of hot and cold water in plumbing, heating and air conditioning systems. the expansion ring technology is based on the great elasticity of PEX-A pipes, which after expansion, and thanks to their plastic memory, contract until they recover their initial dimensions, pressing on the body of the fitting, so that a safe and durable joint is achieved, without the need to use joints with a greater water flow than other jointing systems