An operator was using traditional long-nose needle-and-seat-trim heater chokes supplied by a third party on natural gas production units (GPUs) in the Utica Shale to control flow rate and pressure. Gas was heated before entering the choke welded to the outside of the heater vessel; the long nose enabled positioning of the choke trim inside the heater. These measures counteracted the Joule-Thomson cooling effect produced at the choke trim by the gas as it expanded because of the pressure drop through the choke. Thus, ice and hydrate formation and the consequent blockages were prevented.

The large pressure drop and sand in the flow were causing the chokes to erode in a matter of weeks, resulting in loss of well control and frequent shut-ins to repair the chokes. The operator required a more robust solution.