Interfacing electronic pressure transmitters on high-temperature processes can be problematic.
CEI’s pressure transmitters can be remotely mounted and connected to the process via a capillary and diaphragm isolator assembly. The service temperature is limited by the vapor pressure of the fluid, which is used to fill the assemblies, typically 400°F (205°C) for silicone oil.
CEI can supply a high-temperature chemical seal and capillary attached to a pressure transmitter, filled with NaK (sodium-potassium eutectic alloy). NaK is a form of liquid metal that stays liquid from 9.3°F (-12.6°C) up to 1,450°F (788°C) at atmospheric pressure. The maximum temperature at the seal face is 1,500°F (815°C), allowing even higher working fluid temperatures if the system is installed properly. Note that vacuum conditions can lower the maximum temperature. For additional information and application sheets go to Alkali Metals/Equipment/High-Temperature Pressure Transmitters.
Written By Don Finnerty