Gages for Parr pressure vessels can be furnished with either 3-1/2 inch or 4-1/2 inch dials in any of the ranges shown in the table below. All have stainless steel Bourdon tubes and 1/4 inch NPT male connections. Alloy 400 gages are available on special order. Accuracy is .5% of full scale for the 4-1/2 inch size and 1 percent for the 3-1/2 inch gages. All standard gages include dual scales, with graduations in both pounds per square inch (psi) and bars. Gages in Pascal units are available on special order. Compound gages which show vacuum to 30 inches of Mercury and positive pressures to 300 psi/20 bar are also available.

When ordering a special gage, specify the gage diameter, the desired range and scale units.

The gage on a pressure vessel should be 150 percent of the maximum operating pressure. This allows the gage to operate in the most accurate pressure range and prevents the gage from being stressed repeatedly to its full range, which will effect the calibration.