Pito/Static tubing kits

Post by **Spike** » Wed Mar 07, 2007 2:51 pm

I see lots of people using the pitot static tubing kits that are coming from safeAir.

Other than ease of routing, is there a reason to use these? They sure look nice. I have been told though that its not a good idea to use these kits with heated pitots due to the temperatures that can be generated by the pitot tube. The concern was the failure of the tubing where it attatches to the pitot.

Any experiences?

John

cjensen · Post by **cjensen** » Wed Mar 07, 2007 3:14 pm

I've seen a couple of installs that make up for this by using a lead to the nylon line off of the pitot tube made form a different material. Can't remember what was used though...

svanarts · Post by **svanarts** » Wed Mar 07, 2007 3:29 pm

Could you just run a length of aluminum tube to isolate the heat from the plastic?

smithhb · Post by **smithhb** » Wed Mar 07, 2007 3:34 pm

I will be using the Gretz heated pitot and will connect to the pitot with -4 aluminum tubing and run to the wing root. From the wing root I will connect to poly tubing and run through fuselage.

Post by **Spike** » Wed Mar 07, 2007 3:40 pm

Good thought Bret. I had thought of that briefly. Im curious as to what those who went straight to the poly think too.

smithhb · Post by **smithhb** » Wed Mar 07, 2007 4:14 pm

The Gretz install sheet that comes with the pitot actually states to not use poly tubing closer than 18" to the pitot tube (or it will melt).

Every install I have seen has AL tubing at the pitot and then converting to poly. Some installations use an 18" piece of AL (per the plans) and others have been random lengths. Checkoway went ahead and ran the AL to the wing root...seems a good idea to me.

captain_john · Post by **captain_john** » Wed Mar 07, 2007 6:32 pm

Well, I did a little bit of benchtop engineering to this end.

I hooked up the pitot to a power source and checked the temp of the AN fitting. I could hold it in my hand. I would then speculate that it was not much hotter than body temperature.

Considering that on a hot day on the ramp the wins could get upwards of 110-120 degrees F, I considered this to be within tolerance.

That being said, I may connect directly to the pitot with the plastic line. Before flight, I am going to attempt to intentionally melt the sucker by conducting a destructive test under the worst conditions possible and examining the outcome.

Perhaps you should too?

CJ

Post by **Spike** » Wed Mar 07, 2007 7:48 pm

Ive looked around and talked with a local builder tonight. I think I am going to go with the above idea of running an aluminum line out to the wing root, and then poly from there in to the panel. It seems like the safest option.

Wicked Stick · Post by **Wicked Stick** » Fri Mar 09, 2007 12:24 am

Spike wrote:Ive looked around and talked with a local builder tonight. I think I am going to go with the above idea of running an aluminum line out to the wing root, and then poly from there in to the panel. It seems like the safest option.

Thats what I did on mine...
My ole Grumman had only about 12" of aluminum line coming from the pitot and the rest was poly. It never melted, but I figured 3 or 4 feet would be better for the RV.