Daily maintenance of pressure transmitters

1. Check the size of the installation hole: If the size of the installation hole is not appropriate, the threaded part of the sensor is easily worn during installation. This not only affects the sealing performance of the equipment, but also prevents the pressure sensor from fully functioning, and may even pose hidden dangers. Only suitable installation holes can avoid thread wear (Thread Industry Standard 1/2-20 UNF 2B), and installation hole measuring instruments can usually be used to detect installation holes and make appropriate adjustments.

2. Keeping the installation holes clean: Keeping the installation holes clean and preventing melt blockage is crucial for ensuring the normal operation of the equipment. Before cleaning the extruder, all pressure sensors should be removed from the barrel to avoid damage. When dismantling the sensor, the molten material may flow into the installation hole and harden. If these residual molten materials are not removed, it may cause damage to the top when reinstalling the sensor. The cleaning kit can remove these residual molten materials. However, repeated cleaning processes may deepen the damage caused to the sensor by the mounting holes. If this situation occurs, measures should be taken to raise the position of the sensor in the installation hole.

3. Choosing the appropriate location: When the installation position of the pressure sensor is too close to the upstream of the production line, unmelted material may wear down the top of the sensor; If the sensor is installed too far back, there may be a stagnation zone of molten material between the sensor and the screw stroke, where the molten material may degrade and the pressure signal may be distorted; If the sensor is too deep into the barrel, the screw may touch the top of the sensor during rotation and cause damage. Generally speaking, sensors can be located on the barrel in front of the filter screen, in front and behind the melt pump, or in the mold.

4. Carefully clean; Before cleaning the extruder barrel with a wire brush or special compound, all sensors should be removed. Because both cleaning methods may cause damage to the sensor's diaphragm. When the barrel is heated, the sensor should also be disassembled and the top should be wiped with a soft cloth that will not cause wear. At the same time, the holes of the sensor need to be cleaned with a clean drilling machine and guide sleeve.