Turn valve for Pitot velocity tube

[cspeier]

Hello guys

Long time, hope all is well. I have a question. I'm thinking of finally using my FP1 for velocity as well. I'm currently using a 36" manometer and PT pitot tube. I know John now offers a PS3, which allows you to check velocity during a flow test. I just don't have the time currently to send the box back for the update.

I've been looking at how the FP1 connects the pitot tube. This is my question. John made me some really tight turn knobs. Do you think if I used one and plumbed it for the pitot tube, I wouldn't have any effects on the flow test? Has this been done with success? Or, would I be better off to manually enable the pitot before use?

Anyone have the PS3 option??

Thanks Guys
Chad

[86rocco1]

In order to cause problems, there would have to be a pressure drop across the turn and for that to happen, there needs to be air flow but there's very little actual air flow through a Pitot tube so I doubt that a tight turn would induce enough of a pressure drop to seriously effect the readings. Maybe Bruce or one of the other guys with experience using a Pitot type bench would offer a more informed opinion.

[bruce]

[cspeier]

That's probably the wrong words. They are just a 3 way valve that wont leak.

Let me ask you this. Can you just "T" the pitot into the lines? I'm having a hard time getting this to read properly. I'm doing it like the FP1 shows. One port to the PS2+ and one port split to the PS2- and PS1+. I have Larrys FPexcel and when I have it on 28" SSC, it reads a 4 digit number on the correction. I have the FP in mode 3. FYI, I have it hooked up direct to the FP, not "T" into anything.

This is why I've used the manometer for 3 years

[bruce]

So you are trying to use the 3 way valve(s) to connect the pitot and velocity probe and just switch the valve(s) to select either velocity probe or pitot?

[cspeier]

just the pitot tube. I have a orifice bench.

I'm going to forget the valve idea. I just cant seem to get the pitot tube hooked up properly.

[larrycavan]

[larrycavan]

UPDATE on PS3 and FPexcel

I just sent John a test version of FPexcel to try out with a PS3 equipped FP1. Should know something in a day or two.

If this nails it, anyone who's already purchased FPexcel and has upgraded to a PS3 equipped FP1 or bought theirs already fitted but had the older version of FPexcel will get a free upgrade to the new version with the changes for the PS3 setup.

Effective 1/1/2008, FPexcel will ship in 2 different versions. One basic version and one extended version. Prices will be adjusted.

[larrycavan]