Monitors & Gauges

Parts of a hydraulic pressure gauge

Point at a number or a part of the drawing.

1. 1Glycerin-filled case

   Sealed case filled with glycerin, which damps the needle against pump pulsation and vibration. The plug on top closes the filling hole.

   Hydraulic Pressure Gauge

2. 2Dial

   The printed scale, usually in MPa or bar, read through the window.

3. 3Needle

   Sits on the pinion shaft and turns with the movement to point at the pressure.

4. 4Bourdon tube

   Curved, flattened tube closed at the tip. Oil pressure tries to straighten it, and the tip moves in proportion to the pressure.

5. 5Movement

   Link, toothed sector and pinion that turn the small movement of the tube tip into the full sweep of the needle.

6. 6Connection

   Threaded socket that screws into the gauge port. Inside the case it also anchors the Bourdon tube and carries the oil into it.