Situation: The flow rate in a horizontal reactor was out of control.
Operating Conditions: The service was hydrocarbon gas at 1350ºF and 35 psig. The vessel was double walled and reinforced with ¾" carbon steel, 4" refractory, ½" 304H stainless steel and ¾" hex mesh-reinforced abrasion resistant refractory.
Solution: Team hot tapped through the reinforced double walled pipe in two steps, then inserted a special sleeve on a completion plug into the hot tap nozzle. Using a double valve arrangement, small ceramic balls were dropped into the vessel between two baffles until the desired flow rate was established. The unit continued operations.
