Conduits for cooling a hydrocarbon stream and processes for using same. The conduit can include a first inner wall defining a first bore, a second inner wall defining a second bore, and an outer wall disposed about the first and second inner walls. The conduit can also include an annular support wall connected to an inner surface of the outer wall. An end of the second inner wall and an end of the annular support wall can define a perimeter opening that can be in fluid communication with the second bore. An annular flexible ring can be bonded to the annular support wall and can flexibly contact the first inner wall. A substantially annular cavity can be disposed between the second inner and the outer walls and in fluid communication with the perimeter opening. A quench fluid introduction port can be configured to introduce a quench fluid into the cavity.