The invention relates to distributing feed vapor more evenly across the interior space of a reactor vessel utilizing a distributor pipe at the inlet end that initially directs the flow of reactants through a flange plate and a series of ring plates. The ring plates are physical spaced such that vapor along the wall of the inlet is mildly obstructed by the flange plate and the ring plates cause the vapor to alter course temper down any diverse velocities that may create hot spots within the catalyst bed. At the end of the distributor pipe is a deflector which directs the feed vapor upwardly and outwardly in the head space of the reactor vessel.