How to select the range of a pressure transmitter under different operating conditions?
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During normal operation, the operating pressure is 0.02 MPa; during shutdown procedures, the pressure can reach 0.6 MPa. If I choose a diaphragm pressure transmitter with a range of 0–0.05 MPa, will the gauge get damaged due to overpressure during shutdown? What is the pressure resistance of diaphragm pressure transmitters?
If the normal operating pressure is 0.02 MPa, while the pressure can reach 0.6 MPa during shutdown procedures, then it is inappropriate to use a diaphragm pressure transmitter with a range of 0–0.05 MPa. During parking, a pressure of 0.6 MPa far exceeds the upper range limit of the transmitter, which can very likely cause damage due to overpressure. Generally, diaphragm pressure transmitters have a limited pressure resistance; this resistance is usually related to their range. However, in most cases, the transmitters are designed to have some level of overpressure protection. Nevertheless, long-term or extreme overvoltage can still cause equipment damage. It is recommended to choose a pressure transmitter with a higher range, such as 0–1 MPa, to ensure that pressures up to 0.6 MPa can be measured and to provide a certain level of safety. At the same time, it is also necessary to check the specific technical parameters of that transmitter to confirm whether its maximum voltage tolerance meets the requirements of your application. .
The pressure tolerance factor for most instruments is 1.2 to 1.3; that is, if the maximum value is 0.05 MPA, its pressure tolerance is 1.3*0.005=0.045 MPA. Reaching 0.6 after parking can cause damage to the instrument panel. Of course, at present the work pressure is very low; as for how much pressure the hardware itself can withstand, it is possible to consult with the manufacturers of relevant instruments.
Install 2 pressure gauges; use one with a low range for normal operation, and close the valve on the one with the low range during maintenance shutdowns.
In the case where there is no vibration under operating conditions, a pressure transducer with a range of 0.8 MPa can be selected. For vibration conditions, a pressure transducer with a range of 0.9 MPa can be selected
In fact, the maximum overpressure of the diaphragm is several megapascals; selecting a diaphragm based on the process pressure is no problem