Clean Pressure Transducer and Differential Pressure Transducer

Both the pressure transducer and the differential pressure transducer need to be cleaned regularly. Dust, grease, and tiny particles in the measured medium will deposit in the pressure guiding tube or the sampling valve, directly or indirectly affecting the measurement effect. Therefore, regular cleaning is very important for the normal use of pressure transducers. Before cleaning the pressure transducer, it should be stopped and close the sampling valve. For pressure transducers that use isolation fluid, it can not be cleaned at will, but the isolation fluid should be replaced periodically.
Before cleaning the flow or pressure control system, switch the automatic mode to manual mode. After the cleaning is completed and the pressure transducer is activated, observe if the transducer output is normal. For the control system, the manual mode should also be switched to the automatic mode.

• Pressure transducer cleaning operation

Firstly close the secondary valve of the pressure transducer, then open the drain valve to drain the dirt. After closing the drain valve, observe the leakage in the pressure guiding tube and the valve connector, and if so, handle it. If the pressure guiding pipe and valve connectors are used for a long time, sometimes the pressure guiding pipe or the valve is swayed, so leakage will occur. For general measured medium, starting the pressure transducer only need to open the secondary valve. For steam pressure, the secondary valve must be opened after the steam condensate fills the pressure tube. After starting, loosen the drain valve and exhaust valve on measuring chamber of the pressure transducer. In this way, it can except replace the medium in the measuring chamber, also can drainage and exhaust.

• Differential pressure transducer cleaning operation

For the differential pressure transducer measuring general medium, first close the negative pressure valve of the three valves manifold, then open the balance valve, and then close the positive pressure valve. Then open the drain valve and drain the positive and negative pressure guiding tubes. After closing the drain valve, observe if there is leak in the pressure guide tube and the valve connector. Then open the positive and negative pressure valves. Loosen the drain and exhaust valves on the positive and negative measuring chambers of the transducer. Finally, close the balancing valve and the differential pressure transducer can be activated.
For differential pressure transducers with condensers such as steam flow measurement, the method for closing the three valves manifold and cleaning method are the same as above. Note that the differential pressure transducer must be activated after the steam condensate fills the pressure tube.

• Steps for differential pressure transducer purge

After a period of use, the differential pressure transducer installed in the industrial field will have different degrees of sediment or foreign matter in the pressure guiding tube and the transducer. These impurities will block the tubing of the pressure measurement instrument and cause measurement errors. In order to maintain the accuracy of the differential pressure transducer and achieve satisfactory performance, the transducer and piping must be cleaned regularly to keep it clean. Normally, the differential pressure transducer should be purged in the following order.

1. Close the shutoff valve of the high pressure side on conduit and the shutoff valve of high pressure side on the three valves manifold.
2. Confirm that the pressure equalization valve is closed.
3. Close the shutoff valve of the pressure guiding tube on the low pressure side and the shutoff valve of the low pressure side on the three valves manifold.
4. Slowly open the vent plug to remove pressure.
5. Open the shutoff valve of the high pressure side on the three valves manifold and the shutoff valve of the pressure guiding tube on the high pressure side.
6. Open the pressure equalization valve and purge the pipe with the vent plug on the high pressure side.
7. Close the shutoff valve of the high pressure side on the pressure equalization valve and three valves manifold. Close the shutoff valve of the pressure guiding tube on the high pressure side.
8. Open the shutoff valve of the low pressure side on the three valves manifold. Open the shutoff valve of the pressure guiding tube on the low pressure side.
9. Open the pressure equalization valve and purge the pipe with the vent plug on the low pressure side.
10. Close all valves and follow the normal procedure to put the differential pressure transducer into operation.
    

• Steps for cleaning the inside of the differential pressure transducer

1. Remove the hex bolt for clamping the chamber cover of the pressure transducer, and then remove the chamber cover of the pressure transducer.
2. Wash the diaphragm and chamber cover with a soft brush and solvent. Be careful not to deform or subject the transducer diaphragm to any damage.
3. When reassembling the chamber cover of the differential pressure transducer, replace the new gasket as needed.
4. For bolts used to clamp the chamber cover, the differential pressure transducer should be assembled according to the specified tightening torque.