CAPPA Tech Tips—Pressure Gauges

There are likely several hundred or more on your campus, but are they properly sized? Pressure gauges typically have the specified isolation valve (or trumpet valve), snubber, or pig tail. Proper sizing can present serious issues when miscalculated. The accuracy of the gauge is not always what is shown on the gauge face. Most bourdon tube mechanical pressure gauges are accurate between 1/4 and 7/8 of the gauge range. It is not a linear relationship. For example, the gauge shown to the right would be most accurate between 15 psi and 52.5 psi.