Stainless Steel-Strainer fittings GN 7405 Stainless Steel-Strainer fittings are suited for assembly into piping systems as upstream or downstream protection devices. Depending on the mesh size, particles carried by liquid or gaseous media can be prevented from passing through. Units or housing interiors are thereby protected from foreign objects which can impair function or durability due to their size. The housing is separately bolted through a union nut, making assemblydisassembly easier and allowing the strainer insert to be exchanged if necessary.