----- Original Message -----

From: Kelly Troyer

To: Rotary motors in aircraft

Sent: Thursday, July 21, 2005 10:34 PM

Subject: [FlyRotary] Re: TES "O" Rings

George,

     Just what I was looking for !! Now I wonder what percentage of the

groove area that "Creavy" says needs to be filled and do the teflon-

silicon O-rings expand (grow) under heat ??

--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2

-------------- Original message from "George Lendich" <lendich@optusnet.com.au>: --------------

Kelly,

I see what you mean - a quick check of areas reveal a ratio of area of grove  to "O" ring cross sectional area as:-

1. .093 = 1: .924343 ( for the .065x .113) proven fit - outer "O" ring!!

 

2. .098 = 1: .859       ( for the .065x .135) OK

3. .1    =  1: .8945868( for the .065x .135) OK

4. .103 = 1: .9490484 ( for the .065x.135) TOO BIG.

 

Given the crush 'cross section' is different, but the Teflon flows under that pressure, 2 and 3 should be OK - I'm using your dimension measurements.

 

George ( down under)

George and All,

       I just realized I did not answer your question.......I wanted to find a

cross section of the PFA-SIL that was close to the .098 as called out

in earlier posts for the inner coolent O-ring......I measured the coolent

O-ring grooves of my housings........Both inner and outer grooves

measured .065 thousands deep.......Width of the inner was.135 thousands

and width of the outer was .113 thousands........Now can someone much

better in math than me figure what diameter of O-ring can we use in the inner

groove wthout causing a hydraulic rupture......The inner coolent O-ring sees

more heat and pressure than the outer O-ring !! On paper it appears that

a .093 thousands O-ring has enough crush according to the depth of the

groove but it is free to rattle around in the .135 width.........IMHO

--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2

-------------- Original message from keltro@att.net (Kelly Troyer): --------------

George,

     I was trying to find out what diameters (cross section) of  the high temp

(500 degree f) PFA-SIL was available.........I wonder if the (450 degree f)

FEP-SIL might be good enough for the coolent O-rings but use the high

temp for the rotor side seal O-rings........If the coolent seals ever see even

450 degrees the aluminum rotor hsgs will probably start to crush !!

 

"Opinions"

--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2

-------------- Original message from "George Lendich" <lendich@optusnet.com.au>: --------------

Kelly,

What was that in relation to.

George ( down under)

Group,

   More info from "Creavey"

--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2

From:	"Jeff Chrysler" <jeff@creavey.com>     Save Address     Reminder
To:	"Kelly Troyer" <keltro@att.net>
Subject:	RE: Sil-PFA .098 availability
Date:	Thu, 21 Jul 2005 17:12:27 +0000   [View Source]

PFA is available in .103” cross section.   Jeff   From: Kelly Troyer [mailto:keltro@att.net] Sent: Thursday, July 21, 2005 11:48 AM To: Jeff Chrysler Subject: RE: Sil-PFA .098 availability       Jeff,       Thanks Jeff........What diameters are available in PFA-SIL........  .100 would  probably work if available.     Kelly Troyer