The Importance Of Accurate Instrumentation

A sailor from a destroyer said to a submariner, “It must be scary, going to sea on a ship that’s designed to sink!”

The submariner replied, “It must be REALLY scary, going to sea on a ship that operates at test depth ALL THE TIME!”

The implication, of course, is that a destroyer could not survive a dive to any depth. Oh, and submariners don’t call it “sinking;” we call it “diving,” because submarines are also designed to perform an all-important maneuver known as “surfacing.” There are no guarantees, of course, but the odds are absolutely in our favor, due to the highest caliber of engineering, fabrication, inspection, and training that make the Silent Service so successful.

I thought of this today because of an event that happened on this day in 1973: USS Greenling (SSN-614), a US Navy fast attack submarine, accidentally went below her test depth, and actually approached crush depth, due to a sticky needle on the main depth gauge in the Control Room. According to unofficial reports, a junior enlisted man noticed that the seawater pressure reading on another gauge indicated they were far deeper than the depth gauge was showing. Official reports said they surfaced rapidly (I bet), immediately returned to port, and underwent an extensive inspection in drydock before returning to duty.

USS Greenling – Depth Gauge reading zero (assumed)

Now, your plant’s compressed air system instrumentation may not be as life-or-death critical as a submarine’s depth gauge, but there’s still no reason to skimp on, or settle for, second-rate gear that might cause you undue hassle. For instance, I recently had the pleasure of testing a customer’s Model 6061 1” Stainless Steel Line Vac in our Efficiency Lab – they weren’t able to draw our published vacuum rating (-42” water) or flow rate (14.7 SCFM), when supplying compressed air at 80psig. Curiously, they were getting values that corresponded with operation at 70psig. Using their pressure gauge and commercial-grade inline flow meter, I verified it was indeed under-performing, with 80psig compressed air supplied…this was measured UPSTREAM of their flow meter, however. I installed a pressure gauge at the Line Vac’s inlet port (downstream of the flow meter) and found that the flow meter was (quite unexpectedly) responsible for a 10psi pressure drop! Once the supply was regulated to provide 80psig at the inlet to the Line Vac, we found that it performed as specified.

EXAIR’s Digital Flow Meters, on the other hand, won’t restrict your compressed air flow at all. They’re easy to install…you simply drill two small holes in the pipe, using the included Drill Guide Fixture. They’re just as easy to remove, if you need to, and their holes can be covered with blocking plates (sold separately.)

Our Summing Remote Display can be easily wired to any Digital Flow Meter, and mounted up to 50 feet away. With the push of a button, you can also cycle the display to show not only current compressed air flow, but the previous 24 hours’ usage, and total cumulative usage.

For the ultimate in data management, our USB Data Logger connects just as easily to a Digital Flow Meter, and can be removed and inserted into any available USB port on your computer. It comes with software that will automatically graph your compressed air usage, or you can import the data directly into Microsoft Excel®. Since its introduction early last year, it’s won Environmental Protection Magazine’s New Product of the Year Award, Plant Engineering’s Product of the Year Gold Award, and Design News deemed it a “Better Mousetrap” Award Finalist.

In closing, here’s our Senior Application Engineer, Joe Panfalone, holding the Plant Engineering Gold Award. In case you were wondering, the other three are for our Model 1114SS Large Super Air Nozzles, our Dual High-Temperature Cabinet Cooler Systems, and Siphon-Fed Atomizing Nozzles, all of which were introduced in 2012, with great success – hence the literal armload of awards!

If you use compressed air, odds are very good that EXAIR products can improve your results. Let’s talk!

Russ Bowman
Application Engineer
EXAIR Corporation
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