System pressure gauges are often required to provide more accurate system pressure readings than regulator gauges can provide. Pressure gauges:
- are most accurate if used within midrange and therefore should have a range of about 2 X MAWP;
- should read at least 1.2 X MAWP;
- must be made from materials that are compatible with system contents and pressures;
- must be safety-type gauges if used in high-hazard applications (for example, the gauge must have safety glass and a blowout back);
- should be protected with a PRD; and
- should be protected with a snubber (a flow inhibitor) against surges or pulses.
Source: Los Alamos National Laboratory