A cross is used in pipe systems as a connecting element. It has four inlets and outlets, which are fastened to pipes using a thread or adhesive sleeve. There should be a cotton strap or Teflon tape as insulating material between the thread of the pipe and that of the crosspiece. The crosses are often used if an installation line is to be divided into three additional lines. In addition, fittings such as PVC ball valves, stainless steel ball valves or even accessories such as siphons can be fastened directly to the inner thread or adhesive sleeve. Crosses from NieRuf comprise high quality stainless steel 316 and are available in the nominal widths 1/4", 3/8", 1/2", 3/4", 1", 1 1/4", 1 1/2" and 2" inches. They are also available in high quality plastic PVC-U with adhesive sleeve in the nominal widths d20 - d63 or brass with connection sizes 3/8" - 2" inches. The inlets and outlets are arranged at a 90° angle. As a result of the stainless steel, brass or PVC, the crosses can be installed by NieRuf in a large number of applications. Frequently they are used in industry and trades. They are used in heating systems, in the chemical industry and in biogas plants.