How to operate the three-group valve of the instrument, and what should be noted?
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How to operate the three-group valve of the instrument, and what should be noted?
Open the balance valve first, then open the positive pressure valve, close the balance valve, and then open the negative pressure valve
During operation, the sequence is to open the positive pressure valve, close the balance valve, and then open the negative pressure valve； When shutting down, the sequence is to close the negative pressure valve, open the balance valve, and then close the positive pressure valve. Avoid turning on only the positive pressure valve or only the negative pressure valve without activating the balance valve, as this can damage the transformer due to the high pressure from one side.
The current differential transformers have a very strong single-sided overvoltage protection capability, so be extra careful when operating them
Modern pressure transmitters all have the ability to resist single-phase pressure; there’s no need to worry about this with ordinary ones. However, extra care is required when operating three-valve assemblies filled with isolation fluid or condensate.
The operation of the three-valve assembly should involve flexible selection of procedures based on the actual conditions on site, with the basic principle being to avoid pressure being applied to the transmitter from only one side. Precautions: 1. Prevent condensate from leaking; 2. Prevent high-temperature media from flowing through the three-valve assembly for extended periods of time
Open the balance valve, open the positive pressure valve, close the balance valve
For the corresponding gas, during shutdown, the balance valve can be opened first, followed by closing the valves on the positive and negative pressure sides； In the case of condensate, it is necessary to first close the valve on the positive pressure side, open the balance valve, and close the valve on the negative pressure side. The three valves cannot all be in the open position at the same time, in order to prevent loss of condensate from affecting the measurements. To shut it down, perform the opposite operation.