Differential Pressure Gauges

Differential pressure gauges are often found in process systems in many industries and settings. Simply, they measure the difference in pressure between two points on a system. Differential pressure gauges have two inlet ports that will connect to both pressure sources, gauge will then react to any pressure differential and show the reading on the dial.

GNW offer a range of differential pressure gauges for a wide variety of applications and industries. Manufactured as either diaphragm (cell), capsule or Bourdon tube type gauges, we can offer many different configurations to suit your process.

Differential pressure gauges can be used in many ways, for example it could be the pressure difference across a filter, valve, or restrictor. As a filter gradually becomes dirty and clogged, it will restrict the flow of air through it. The clogged filter restricts the air causing less to pass through it therefore decreasing the pressure on the down-stream side – this increases the pressure differential across the filter that can be measured by the gauge. Filters can be cleaned or changed when a predetermined differential pressure is reached to ensure they are performing correctly.

In a similar way, differential pressure gauges can also be used to measure flow rates in pipelines. A flow nozzle of some type is inserted into the pipe and the up-stream and down-stream pressure are monitored by the gauge. This pressure differential across the nozzle can then be converted into a flow rate.

Differential pressure gauges can also be used to measure and indicate liquid levels in sealed tanks. Whereas a normal tank contents gauge uses the differential pressure between the fluid and ambient pressure, a differential gauge can measure the differential between the fluid pressure and the pressure contained in the tank. The difference between the two can then be converted by the gauge calibration into a very accurate level or contents reading.