This cartridge grundfos mechanical seal is a smart design pump seal for grundfos vertical pump, this seal suit for grundfos CR CRI and CRN series vertical water pumps. As a special cartridge mechanical seal, we follow the original grundfos design 100% for this seal, this help to avoid any installation mistake when you install the seal for the grundfos pump, and make installation easy. Our grundfos mechanical seal frame and spring are made by strong quality stainless steel SS304 ( SS316 available too) material, help to against rusty problem. We use SSIC (Pressureless Sintered Silicon Carbide) as stationary and rotary seal face, it is much better than normal material RSIC (Reaction sintered Silicon Carbide), offer more wear resistance for the grundfos mechanical seal. For Rubber part, normally people choose EPDM or VITON for secondary seal. Our grunfos mechanical seal will make your pump as good as new and reduce downtime, and last longer time when pump running.