Multi-purpose Stainless Steel Coupling provides an economic alternative to conventional pipe jointing techniques for plastic and metal pipes. George Fischer Piping Systems Pvt. Ltd.. Supplies Multi-purpose Stainless Steel Coupling. George Fischer Piping Systems Pvt. Ltd.. Offers a wide range of safe corrosion-free plastic piping systems for domestic and industrial applications. The Multi-purpose Stainless Steel Coupling is a non-corrosive coupling suitable for welding, flanging and threading applications.