Seeking advice on selecting the range for local pressure gauges
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The pipeline table provided by the process shows the operating pressure and design pressure for that section of pipeline; for example, for PG4011 in the figure below, the operating pressure is 0.005 Mpa and the design pressure is 0.1 Mpa. My questions are: 1: When selecting the range of a pressure gauge, is it necessary to include the design pressure as well? For example, should one choose a range of 0~0.2 Mpa, or can one opt for 0~0.01 Mpa without considering the design pressure? 2: If the design pressure is not taken into account, is it reasonable to choose a range of 0~0.03 Mpa for an operating pressure of 0.005 Mpa? 3: What criteria or conventions are used to determine the range of a pressure gauge? Thank you all
On-site display gauge: measures the pressure of stable media, ranging from 1/3 to 1/2； Measure the pulse medium pressure, between 1/3 and 2/3 ； Since the pressure shown in the table is very low at 5 Kpa, a diaphragm-type pressure gauge should be selected. In my opinion, choosing a range of 0–30 Kpa is more than sufficient to meet the requirements; it’s likely that the design team selected a higher value taking into account the purging pressure required for WG during startup and shutdown periods
When designing a pressure gauge, consideration is given to ease of measurement under normal operating conditions; the design does not take into account situations involving abnormalities. For example, if there is a concern that the pressure might be too high and cause the gauge dial to break, a pressure gauge with a pressure relief valve can be used. However, there is one principle regarding the range selection: the operating pressure should fall between 1/3 and 4/5 of the gauge’s range.
In this case, it is sufficient to choose the gauge range based on actual conditions; there is no need to consider the design pressure, otherwise it will be impossible to select an appropriate range.
The last edit to this post was made by loonfan on 2021-11-5 at 09:54. The range of 1/3 to 2/3 of the pressure gauge’s scale is sufficient to cover the operating pressure; however, if the range is less than the design pressure, a gauge saver should be used
In my opinion, pressure gauges are used solely for operational monitoring, and should be selected based on the operating pressure.
In my opinion, pressure gauges are used solely for operational monitoring, and should be selected based on the operating pressure.
0.005 Mpa, with a design pressure of 0.1 Mpa. 1. The range is selected based on the operating range: 0-10 KPA or 0-16 KPA; these are basically diaphragm pressure gauges of the YE series. 2. Consult the manufacturer to find out what the \"burst pressure\" of YE is. If it is greater than 0.1 M, even if the safety valve activates, the pressure gauge will not \"burst\", and the entire system remains safe. 3. The overload pressure for standard pressure gauges is 120%; once the pressure exceeds this value, the gauge will not return to its normal reading, and the nominal accuracy cannot be maintained (the elasticity is compromised). This can be achieved using an overpressure protector (GAUGE SAVER), that is, it shuts off the inlet pipeline when the pressure exceeds 120%. However, overvoltage protectors of the KPA level are rare and bulky. Typically, the \"burst pressure\" of stainless steel spring tubes is around 20 MPa, and pressure gauges cost around a few hundred yuan. A overvoltage protector costs around 300-500 yuan; you can consider choosing one based on your needs.