1. Sewage discharge is mainly aimed at differential pressure transmitters, pressure transmitters, float level gauges and other instruments. Since the measurement medium contains dust, oil, tiny particles, etc., which are deposited in the reverse pressure pipe (or deposited in the pressure sensing pipe), it is directly or indirect effects on measurement. The sewage discharge cycle can be carried out regularly due to the instrument engineering’s own plan based on practice.
2. Before discharging sewage, you must contact the process personnel and obtain their approval before proceeding.
3. Before draining the flow or pressure regulating system, you should first switch from automatic to manual to ensure that the opening of the regulating valve remains unchanged.
4. For differential pressure transmitters, the positive and negative pressure valves composed of three valves should be closed before draining.
5. Place a container under the drain valve, and slowly open the drain valves of the positive and negative pressure guide pipes to allow materials and dirt to enter the container to prevent materials from being discharged directly into the ditch, otherwise it will not only pollute the environment but also cause waste.
6. Due to the poor quality of the valve, the sewage valve will not close after being opened and closed several times. The emergency measure is to add a blind plate to ensure that the sewage valve does not leak, so as not to affect the measurement accuracy.
7. Open the positive and negative pressure valves of the three-valve group, and move the sewage (exhaust) screw on the pressure difference transmitter body for sewage discharge. After the sewage discharge is completed, tighten the screw.
8. Observe the instrument on site until the output is normal. If the system is adjusted, switch from manual to automatic.