Compound Gauge, 2.5" Dial, -30 inHg to 300 PSI, 3/8" Tube Stub
ABOUT THIS PART
A 2.5 inch compound gauge that reads vacuum and pressure on one dial, from -30 inHg through 0 to 300 PSI (20.7 bar), with a 3/8 inch tube stub lower connection. $114.95.
SPECIFICATIONS
| Dial size | 2.5 in (63 mm) |
|---|---|
| Range | -30 inHg / 0 / 300 PSI, which is 20.7 bar at full scale |
| Second scale | -1 to 21 bar |
| Dial scales | PSI and bar, both printed on the face |
| Connection | 3/8 in tube stub, lower mount |
| Nut and ferrule | Not included, customer swages the stub into their own fitting |
| Connection note | Tube stub, not a pipe thread. Does NOT thread into 1/4 in NPT |
| Accuracy | +/- 1.6 % of full scale, ASME B40.100 |
| Case | 304 stainless, crimped ring |
| Lens | Acrylic |
| Bourdon tube and socket | 316 stainless |
| Movement | 316 stainless |
| Case fill | Glycerin |
| Fill temperature rating | -40 C (-40 F) |
| Below the fill rating | Drain the fill before running colder than -40 C (-40 F) |
| Operating temperature range | -40 C (-40 F) to 65 C (150 F) |
| Wetted materials | 316 stainless |
| Qualified in | ECR-250902-R0, Appendix A, item 5, third party equipment certification report |
| Dial marking | N.B. Oler logo, black and gold |
| Built or stocked | Built to our specification, stocked in Bend, Oregon |
| Price | $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
| Dial size | 2.5 in (63 mm) |
| Range | -30 inHg / 0 / 300 PSI |
| Second scale | -1 to 21 bar, printed on the same face |
| Connection | 3/8 in tube stub, lower mount |
| Accuracy | +/- 1.6 % of full scale, ASME B40.100 |
| Case | 304 stainless, crimped ring |
| Bourdon tube and socket | 316 stainless |
| Movement | 316 stainless |
| Lens | Acrylic |
| Case fill | Glycerin, rated to -40 C (-40 F) |
| Operating range | -40 C (-40 F) to 65 C (150 F) |
| Wetted materials | 316 stainless |
| Qualified in | 3P Certz engineering report ECR-250902-R0, Appendix A, item 5 |
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
The gauge maker's rule is to pick a dial about twice the working pressure, with working pressure sitting in the middle half of the scale, 25 to 75 percent. On a 300 PSI (20.7 bar) dial that middle half is 75 to 225 PSI (5.2 to 15.5 bar).
The 250 PSI (17.2 bar) on an N.B. Oler system is the design pressure, not where the needle sits on a run. Normal operating pressure falls inside that 75 to 225 PSI band, and the dial still has scale left above the design pressure and full vacuum below it. A 60 PSI dial has neither, which is why the 300 PSI range is the one we stock for extraction service.
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.
| FITS | The gauge port on N.B. Oler columns, vessels and end caps that takes a 3/8 in tube stub in a compression fitting. Replaces the gauge originally supplied on those systems. Supplied as a bare tube stub with no nut and ferrule set. Does NOT fit a 1/4 in NPT gauge port without an adapter, which is the port most third party extraction equipment uses. |
|---|
▦ IN YOUR MANUAL
This part appears in the operator manual that ships with your system. The QR code there links to this page.
◈ REFERENCE FOR THIS PART
COMMON QUESTIONS
Does a nut and ferrule set come with it?
No. The gauge ships as a bare 3/8 inch tube stub. You swage it into your own 3/8 inch compression fitting, so order the nut and ferrule separately if you do not already have them on the port.
Will this thread into my 1/4 inch NPT gauge port?
No. The connection is a 3/8 inch tube stub, which goes into a 3/8 inch compression fitting, not a threaded port. Check the port before ordering.
Does it read vacuum as well as pressure?
Yes. It is a compound gauge. The dial runs from -30 inHg through 0 and up to 300 PSI (20.7 bar), so one gauge covers pull-down and run.
What is the operating temperature range?
-40 C (-40 F) to 65 C (150 F).
How cold can it go?
The glycerin fill is rated to -40 C (-40 F). If you are taking the vessel below that, drain the fill first. Glycerin stiffens below its rating and the pointer stops tracking.
Why is it liquid filled?
Liquid fill damps pointer flutter from pump pulsation and compressor cycling, which is what wears out a dry gauge on an extraction system.
Do you still sell the 60 PSI version?
No. The 60 PSI range was an ethanol-era part and it is discontinued. The -30 inHg to 300 PSI is the only range we stock.
What is the accuracy?
Plus or minus 1.6 percent of full scale, to ASME B40.100.
Is this the same gauge that came on my system?
Yes, if your system is an N.B. Oler build. Same dial, same range, same 3/8 inch tube stub. The face carries the N.B. Oler logo in black and gold, so it is easy to tell against a generic replacement.
Does the dial read in bar as well as PSI?
Yes. The face is printed with both scales, -30 inHg to 300 PSI and -1 to 21 bar.
What range should I pick for my system?
The gauge maker's rule is a dial about twice the working pressure, with working pressure in the middle half of the scale. On a 300 PSI (20.7 bar) dial that middle half is 75 to 225 PSI (5.2 to 15.5 bar). The 250 PSI (17.2 bar) on an N.B. Oler system is the design pressure rather than where the needle sits on a run, so normal operating pressure falls inside the band and the dial still covers full vacuum below it and the design pressure above it.