A support system for process piping and method of installation are presented. An adjustable hanger rod assembly includes a rod with oppositely oriented external threads at opposite ends thereof. These threads are adapted to mate with internal threads in respectively associated sleeves. One of the sleeves is fixed to a support system, while the other sleeve is fixedly secured to a pipe clamp. The oppositely oriented threading of the rod allows the rod to operate as a turnbuckle, such that rotation of the rod adjusts the elevation of the pipe clamp and an associated pipe retained thereby. Once a desired adjustment has been achieved, the rod and associated pipe clamp may be locked into position by tack or spot welding of the rod to the associated sleeves.