On gauges

Below a photo shows a 1/4" NPT gauge on the air supply to a pre-action system.  The gauge contains an "X" on the gauge face.  Reasons for the "X" are unknown.

Below a photo shows a non-UL listed pressure gauge on the water feed to a pre-action valve.  There is some evidence of corrosion on the gauge set:

The next photo shows an in situ gauge with an "x" marked on the face.  Unknown reason for the "X".  The gauge is not listed for fire protection service.

This next photo shows a listed pressure gauge.  The manufacturer's date code (B11) is indicated by the yellow arrow:

The following photo will show a mechanically damaged gauge used in a nitrogen (N2)  tank.  N2 was being utilized to re-charge dry chemical pressurized cylinders:

Below, an unlisted air pressure gauge on a pre-action system is shown:

The photo below shows a "water" pressure gauge on the air side of the dry valve.

The following photo shows a dry valve impaired (shut off) for service.  All gauges reading zero.

The following gauge found on a Multimatic A-4 pre-action riser is not listed for fire protection:

Below a photograph shows a pressure gauge installed on the air side of a dry pre-action system.  The gauge  manufacturer date code is 1991.  There is no evidence of recent calibration. The photo was taken in 2016. 

Photograph below shows an unlisted pressure gauge.  Also note, surface corrosion is present:

The photograph below shows an installed gauge with a manufacturer's date code of 1988.  The photo was taken in 2016.  There is no indication this gauge has been recently calibrated.

The following photo shows a pressure gauge on the air side of a double interlock pre-action valve.  The gauge shows a manufacturer date code of 2004.  There is a sticker indicating the gauge is out of tolerance, but the gauge remains in service. Photo taken in 2016.

The next photo may show a gauge marked with an "X" implying the gauge may be "bad" or out of tolerance.  The gauge remains in service:

The following pressure gauge has likely been field manipulated ("tweaked") to achieve a certain specific pressure (likely 200 PSI for a hydrostatic pressure test).  This action may constitute fraud.

The next photo shows an in situ pressure gauge, the needle is not correctly attached.  The gauge has mechanically failed.

The photo below shows a pressure gauge with a 1991 manufacturer date code.  There is no evidence indicating this gauge has been recently calibrated or replaced:

The following photo shows a pressure gauge that was installed and had the label (as photographed) installed on the gauge:

Gauge rotated so it cannot be seen: