Tailwheel vs impact gun

[SPYDERLK]

Im not sure how big those guns are, but I suspect you used a fairly small tee and the hi velocity air past the gauge port lowered the reading.
.... Years ago I made a setup to test pressure drop at hi flow. I just dug it up and checked it out to refresh my memory. --- With a 50' 3/8" feeder hose having one QC it takes 150PSI to feed 92PSI to an open orifice 0.215 in diameter. Thats well over 50CFM. The actual ID of the hose is more like 7/16", but that may be normal for 3/8 hose AFAIK.:confused3:
larry

I was just browsing and ran across this post. - - I have just now decided to change air couplers because the one I was using was difficult to disconnect. ... Its a 1/4" "Universal" coupler that will accept Industry std shape or ARO shape plugs. I bought 5 from Lowes. It turns out that it is quite high flow for the Industry Standard shape.

While I was doing the change over to the new coupler sockets I used the test jig to flow qualify all the 1/4" coupler socket types I have. Im posting because the info might be useful to some.

,,,All tests were done thru a 50 foot 3/8" air hose fed straight from a 60G tank at 150psi -- NO regulator or coupler at the tank. - The output of the hose was the coupler socket mating with an industry standard shape plug on the test jig. The jig was contrived so that there was no flow across the pressure gauge port.

The Lowes [brass] universal presented 92psi to the 0.215 open exhaust orifice of the jig.

,,,The Oetiker coupler insert and swivel provides a straight thru flow. Test jig flow pressure was 90psi.

The Prevost composite push button release coupler gave 88psi.

,,,The classic Milton [brass] coupler gave 78 psi.

The Milton composite push button safety release coupler gave 77 psi.

,,,Three other Mfg unidentified copy/ clones of the Milton brass coupler gave pressures clustered tightly around 78.

As you can see, the best of these flow quite well in comparison to the legacy couplers.

I am going to settle on the Prevost coupler for everyday use at the tool. - The Oetiker is slightly better flow but its swivel engagement and tool retention has given me trouble in the past. It is great for the wife though because couple/decouple do not require much strength.
,,, I will use my Lowes universal coupler sockets at wall and tank plug ins and for extensions where repetitive change is rare.
The Miltons et al will wait for requirements where only modest flow will ever be needed.