Humidity in aircraft tyres

[drsmiranda]

I thank you all for your time in advance...

Does anyone knows what is the humidity dewpoint admissible in aircrafts tyres?

I need to project a nitrogen tyre inflation equipment (wich i alredy made)but i need to know wich air dryer to install...

Best Regards,

DRSMIRANDA

 

[FieldTeam]

Recommended nitrogen should 99.5% MIL-P-27401, Type 1, Grade A.

 

[drsmiranda]

I produce my own nitrogen because i project PSA ( pressure swing adsorption) nitrogen generators for a long time...The reference you gave me doesn´t tell nothing... You are talking of liquid nitrogen... Normally i produce a -40ºc dewpoint (aproximaly 100 ppm of water content) nitrogen. And i need to know if it is enough...

 

[FieldTeam]

I am sorry.....I am referencing Boeing service letters and maintenance manuals for nitrogen spec for servicing aircraft tires. Liquid nitrogen would not be too good for this application, so that is why they don't reference TYPE 2 LIQUID NITROGEN. The do reference:
MIL-P-27401 propellant pressurizing agent, Nitrogen, Type 1, grade A.
Type 1 is Gaseous
Grade A is 99.5% pure (grade B is 99.99 and grade C is 99.995)

Water, PPM = 26.3 (70degF, 760mm)

As a cross reference, another Nitrogen spec, A-A-59503 Nitrogen, Technical; Type 1 (gaseous); Grade B (99.5 pure) has moisture content Max 26 PPM.

Your question: Does anyone knows what is the humidity dewpoint admissible in aircrafts tyres?
26 PPM per the above specs.

 

[Stache]

I happen to have a copy of Michelin care and service manual and on page 30 Inflating with nitrogen it says: "Many regulatory agencies require the use of nitrogen when inflating tires for aircraft above a specified Maximum Take-Off Weight (MTOW). Michelin recommends the use of a dry, commerical grade nitrogen of at least 97% purity when inflating all aircat tires.

The manual also states; " Oxygen concentrations should never exceed 5%.

In a Michelin tire clas I took they talked about moisture, but I cannot remember the numbers they called out.

You can contact Michelin tires:
Michelin Aircraft Tires
1305 Perimeter Road
Greenville, SC 29605
(877)503-8071

http://www.michelinair.com

Stache