Compound Gauge, 2.5" Dial, -30 inHg to 300 PSI, 3/8" Tube Stub

A 2.5 inch compound gauge that reads vacuum and pressure on one dial, from -30 inHg through 0 to 300 PSI, with a 3/8 inch tube stub lower connection. $114.95.

This is the gauge fitted to N.B. Oler columns and vessels, so if you are replacing one, it is the same part, the same dial and the same connection.

Check the connection before you order

The connection is a bare 3/8 inch tube stub and no nut and ferrule set is included. The stub goes into your own 3/8 inch compression fitting and you swage it on.

It is not a pipe thread and it will not screw into a 1/4 inch NPT gauge port, which is what most extraction gauges use.

Specifications

Why glycerin filled

The fill damps pointer flutter from pump pulsation and compressor cycling, which is what kills a dry gauge on an extraction system.

If you are running the vessel colder than -40 C (-40 F), drain the fill before you take it down. Glycerin stiffens below its rating and the pointer stops tracking.

Picking a range

A dial should read about twice your working pressure, with the working pressure sitting in the middle half of the scale. On a 300 PSI dial that is 75 to 225 PSI, which is where a hydrocarbon system runs.

Two scales on one face

The face carries -30 inHg to 300 PSI and -1 to 21 bar, so one gauge reads for a crew working in either unit. It is printed with the N.B. Oler logo in black and gold, which makes it easy to tell from a generic replacement.

Built to our specification, with our dial, our temperature rating and our range. Stocked in Bend, Oregon.