PID
Thread Content
Does anyone know why the pressure gauge needs to be equipped with a heat tracing pipe on the amine liquid pipeline in the liquid ammonia washing process in the PID diagram, but the thermometer does not need to be added with a heat tracing pipe?
Thermometers are all sheathed and are not in direct contact with the medium. The pressure gauge is in direct contact with the medium. Heat tracing is required to prevent the pressure gauge from freezing.
I would like to ask you about this, why do you need to add a heat tracing duct to the front part, but not add a heat tracing duct to the back when venting the air?
The safety valve is closed under normal conditions, so this section of the pipe is open circuit. Ammonia is prone to crystallization and blockage. Heat tracing is to prevent crystallization! There is no material in the vent line normally. When the safety valve is activated, the high-speed gas will not form crystallization conditions in the pipeline.