On-site pressure gauge color ring
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In many factories these days, the dials of pressure gauges on site are fitted with green, yellow, and red color rings to visually indicate to the personnel on site whether the pressure is within the specified operating limits. Some use yellow to indicate the range from 0 to the lower limit of normal operating pressure, green for the normal operating pressure range, and red for overpressure. Some use green for pressures from 0 up to the normal operating pressure, yellow for pressures from the normal level up to moderate overpressure, and red for even higher pressures. I would like to ask whether there are any **standards specifying the requirements for the arrangement of these color rings?
According to the international standard GB2893-2008 regarding safety colors: Red: Prohibition, danger; Yellow: Caution, warning; Green: Safety. Therefore, when using safety colors on pressure gauges, the colors should be used in the order of green, yellow, and red. In enterprises, pressure gauges (including pressure gauges, air pressure gauges, and oxygen gauges) are mostly diaphragm-type general pressure gauges. The \"Rules for the Calibration of Bourdon-Tube General Pressure Gauges, Pressure-Vacuum Gauges, and Vacuum Gauges\" (JJG 52-1999) were issued by the **Quality and Technical Supervision Bureau on December 22, 1999, and came into effect on April 1, 2000. They are applicable to the calibration of Bourdon-tube general pressure gauges with a measurement range of (0.1–100) MPa. Paragraph 5.5 of these regulations stipulates that the calibration interval for pressure gauges should generally not exceed six months.
Since the process control requirements are different, the color ring markings will definitely vary
How do you apply those color rings?
My opinion on this is that it’s just people being idle with too much time to kill. Good practices are not about formality; as far as I know, pressure gauges do not require colored rings. First: Why are pressure gauges equipped with color rings? In terms of management, some experts see how others do things and declare it to be good, promoting that approach everywhere; while the companies neither understand it nor can they go against what those experts demand. Personally, I think color-coded rings are a good idea, but there must be a need for them and a basis for doing so. Second: the need – difficulties in observation; management requirements related to hazardous working conditions, maintenance needs, etc. In such cases, either an instrument with a larger diameter (such as 150 mm) or a remote-transmission pressure gauge should be used. So the need lies in management aspects. Third: the basis for selection – the range of the pressure gauge can be determined by referring to HGT20507 and SHT3005. However, deciding how to use red, yellow, and blue colors is the responsibility of the technical staff. I’ve seen situations where colors were applied randomly, with all instruments marked in these colors. In any case, since managers order it to be done, no one checks whether it’s done properly. It’s time-consuming and labor-intensive; is it really worth turning a trivial matter into something huge? Fourth: If there are indeed **requirements**, why don’t pressure gauge manufacturers produce them in accordance with those requirements? If there is indeed a need, why doesn’t the purchaser ask the pressure gauge manufacturer to incorporate the indicators directly into the gauge face? Are the red, yellow, and green stickers applied by oneself really effective? Are they applied correctly?
This still needs to be determined based on actual needs
Basis: GB 2893-2008 \"Safety Colors\"
It should be like this: for example, if high pressure alerts and very high pressure alerts are set, the range from 0 to high pressure level is displayed in green, while the range from high pressure level to very high pressure level is displayed in yellow； Values above a certain threshold are shown in red.