Presure tube location, again

[cboggs]

OK, .. just checking this again.

The locations for the presure tubes, .. test presure pick up above the
orifice plate, .. or in the settle chamber just under the test orifice??

Inclined pick ups go above and below the orifice disc???

Anyone know where they are located in a SF-600 ??????

Thanks

Curtis

[Mouse]

This looks correct to me....

John

[cboggs]

Thanks Mouse, ..

so, OK, .. might sound stupid, .. but, .. the vertical is measuring
the pressure drop across the test piece, .. the head, .. the inclined
is measuring the pressure drop across the orifice plate, ..

So, .. when I go to calibrate this thing, .. if I have test plates made
with the same size orifice as the disc, .. I should get 100% on the
inclined, .. then if I flow those same discs on a SF-600 and use
those numbers as my flow range, .. will that work?????

Thanks,

Curtis

[86rocco]

[larrycavan]

[msj442]

is there a standard of how far the tubes go into the chambers on this style of bench?

[Maxflow]

[200cfm]

Not that I am aware of. As long as the entry point is sealed good and the pick up is sensing settled or stable air pressure. You would not want it over the orfice area for example or near the cylinder bore entry point, etc. Mine is off to the sides about two inches entry off the wall. In a air settle area is my preference.

[106-1194218389]

On my bench they are flush with the inside of the chamber wall and in the corners away from the activity and seem to work very well. Very stable function.

[Maxflow]

Thanks guys. What do you think of this tip I drew up for the
end of the pick up tube.

[larrycavan]

Nice drawing.....might be overkill though. I used brake line and drilled the small radial holes in it. Works fine.

I did deburr the cut ends and smoothed them up real well.

[bruce]

Here is a picture of the one I used on my PTS bench build:

[bruce]

Outside:

[Maxflow]

Bruce does that work better than a tube sticking out into the
chamber?

[bruce]

I think you will find different theories on this. I personally like a flush mount pickup, others use the multiple hole setup like the drawing.

Which one works the best?

I sure don't know and would not say I am an expert on it either. But the ones I show in the picture is what I am using in my personal bench build, or a flush tube through the bench wall.

I made my design so if it did not work I could always remove it and try something else. The end goal is to have your pickups located such that they do not get any velocity pressure from the airflow in your bench.