Abstract: A split nut assembly (100) for joining a threaded pipe (90) with a flanged pipe (95), the split nut assembly having a two-piece split nut (110, 130) having locking pins (113, 133) that engage locking apertures (115, 135) to properly align the split nut. A locking ring (150) slidably engages the properly aligned split nut to hold the assembly together. Rectangular apertures (123, 143) are provided on the split nut, that engage corresponding channels (163) in the locking ring, whereby the locking ring is rotationally coupled to the split nut when assembled. Locking tabs (164) hold the locking ring in place after assembly. This split nut assembly allows the pipes to be joined without threading any hardware along the length of either pipe, and with the split nut threads (112, 132) engaging the pipe threads (92) without having to rotate the nut.