Receiver gages should have 4½-inch diameter dials, bronze Bourdon tubes and stems, and ¼-inch NPT process connections. Local instrument air pressure gages on control valves, pneumatic transmitters, and controllers should have 1½-inch or 2½-inch diameter dials. Receiver gages and instrument air pressure gages should be rated Grade B in accordance with ANSI B40.1. Grade B pressure gages are accurate to 2%.
