Level is measured using differential pressure; the positions of the upper and lower nozzles determine this
Thread Content
Colleagues: If differential pressure is used to measure liquid level, how should the positions of the upper and lower flange nozzles on the tank be determined? Is it how much higher and lower than the high and low liquid levels respectively? Thank you
You are from the instrumentation field; the position of the flange connections and nozzles on the tank is determined by the process engineering team. Typically, the normal level indicated by the instrument is around 50% of its measurement range. The upper limit of this range should be higher than the upper alarm and interlock setpoints required by the process, while the position of the flanged connection nozzle should be above the position indicated by the upper limit of the instrument’s range ； Similarly, the lower limit of the instrument’s range should be below the lower limit setpoints for alarms and interlocks as specified by the process requirements, while the position of the flanged connection nozzle should be below the position indicated by the lower limit of the instrument’s range. In fact, the process engineering department specifies the interface location requirements for the equipment industry, and after the instrumentation is selected, it provides the interface dimension requirements for the equipment.
I support the second floor’s view: you are from the instrumentation field, and the location of the flange connections and nozzles on the tanks is determined by the process engineering team. Typically, the normal level indicated by the instrument is around 50% of its measurement range. The upper limit of this range should be higher than the upper alarm and interlock setpoints required by the process, while the position of the flanged connection nozzle should be above the position indicated by the upper limit of the instrument’s range ； Similarly, the lower limit of the instrument’s range should be below the lower limit setpoints for alarms and interlocks as specified by the process requirements, while the position of the flanged connection nozzle should be below the position indicated by the lower limit of the instrument’s range. In fact, the process engineering department specifies the interface location requirements for the equipment industry, and after the instrumentation is selected, it provides the interface dimension requirements for the equipment.