Dwyer pitot tube part number

[65mustang393]

I currently have a Dwyer 166-12 pitot tube for the exhaust and a 167-12 for the intake port, but I'm looking for the Dwyer number for the intake pitot that has the tight .600" radius.

A quick search didn't really come up with anything and I'm hoping someone can point me in the right direction.

Thanks,
Gerald.

[larrycavan]

[gofaster]

Audie Technology offers some small diameter pitot probes, and I think the bend radius is close to that size, go to his website, and you'll see a picture of one of his probes next to a rule to demonstrate it's size.

[hollywood63]

I just was in contact with Dwyer about a pitot. The tightest they can bend is .875 outside to outside. The short end of the J bend is 1.250 and the total lenght is 18" the part number they gave me was 170915-00. Its their 167 series with 1/8" tubing. The price of a 90* bend was something like 50-55 the phone number for them is 219-879-8000
Art

[hollywood63]

hit to many buttons and did a repost :p

[86rocco]

If you can't find one, they're pretty easy to make, here's mine.

[larrycavan]

[86rocco]

I don't think there's any specific ratio that needs to be adhered to. My only concern in making very short is that the pickup port not be affected by any turbulance created at the bend.

I'd never really considered going into even limited production. The probe in the picture is the second of two that I've made and represents about $5-6 worth of supplies and about an hour labour.

[hollywood63]

Rocco
What size holes did you drill in the tubes. The one I made has .040 holes in it but I'm not sure if it is accurate. The readings I get with mine show 400-450 fps which I'm having a hard time believing.
Art

[86rocco]

It's been a while since I made that Pitot tube but I think the holes are around .025".

As for the velocity readings you're getting, why not make a test fixture. A simple piece of straight pvc pipe, a couple feet long mounted on your flow bench, armed with the CFM reading from the flowbench and the I.D. of the pipe you can easily calculate the average velocity through the pipe. Then use your Pitot tube to measure the velocity at the centre of the pipe multiply that by a factor of 0.9 and you should get your average velocity + 5%. That calculation isn't completely accurate but it's close enough to determine if your readings are at least in the right ballpark. For more details on this type of measurement,