Apparatus for measuring the pressure and flow rate of a high temperature corrosive liquid

A flow measuring apparatus configured to enable measurement of a flow rate of a corrosive and/or high temperature process liquid flowing in a process liquid conduit through a valve, the flow measuring apparatus comprising:

• a pressure measuring apparatus comprising:
• a first process liquid pressure sensor in fluid communication via a first vertical tube with the process liquid conduit on an upstream side of the valve, and a second process liquid pressure sensor in fluid communication via a second vertical tube with the process liquid conduit on a downstream side of the valve;
• first and second interface level sensing devices associated respectively with the first and second vertical tubes;
• at least one buffer gas delivery line in gas communication with the vertical tubes;
• and
• at least one buffer gas pressure regulator configured to regulate pressures and/or volumes of the buffer gas in the at least one buffer gas delivery line;
• at least one process liquid temperature sensor configured to sense a temperature of the process liquid;
• and
• a controller in signal communication with the first and second process liquid pressure sensors and with the at least one temperature sensor, the controller being configured to determine the flow rate of the process liquid through the valve according to a temperature of the process measured by the at least one process liquid temperature sensor, and inlet and outlet pressures of the process liquid measured respectively by the first and second process liquid pressure sensors.