The 2 1/2" Febco 826YD Series Reduced Pressure Detector Assemblies were produced from 1989 to 2013. The 826YD is a fused epoxy coated, ductile iron device with stainless steel check assemblies. Bronze, replaceable seats bolt into the body. The relief valve is a side mount, bronze body with external sensing line. Bypass device shoud be a 3/4" Febco 825Y.