The red limit mark for the pump outlet pressure indicates how many times the normal outlet pressure it is

This post was last edited by ylb913 on 2016-9-3 06:44. Selection of the pressure gauge’s measurement range: (1) When measuring a steady pressure, the normal operating pressure value should be between 2/3 and 1/3 of the upper limit of the gauge’s range. ⑵When measuring pulsating pressure (such as the pressure at the outlet of pumps, compressors, fans, etc.), the normal operating pressure value should be between 1/2 and 1/3 of the upper limit of the instrument’s measurement range. ⑶When measuring high and medium pressures (greater than 4 Mpa), the maximum operating pressure should not exceed 3/5 of the upper limit of the instrument’s measurement range. ⑷After the upper and lower limits of the gauge are calculated based on the pressure to be measured, these values cannot be used directly as the gauge’s range. In China, pressure gauges manufactured come in standard ranges: 1 KPa, 1.6 KPa, 2.5 KPa, 4.0 KPa, 6.0 KPa, as well as multiples of 10 raised to the power of n (where n is an integer). Therefore, when selecting a gauge range, it is necessary to use the values specified in relevant standards or specifications. Regarding the red line on the pressure gauge at the pump outlet, you simply need to ensure that it does not exceed the limits mentioned above; generally, the red line is drawn at a point that is between 2/3 and 1/3 of the upper limit of the pressure gauge’s measurement range. If you really require the operator to control the pressure within the range indicated by the red lines, then narrow it down.

This is related to one’s own usage; with stricter control, the working pressure can be a bit higher than normal, while with looser control, it can differ by quite a lot...

What was said on the second floor makes sense, but in reality, posters are usually posted casually