>
     >      >
     >        > What I will use - since I am not into inverted flight ( yet
     >      ?  LOL ) I
     >        > will use the idea of the cylinder rather than the bladder.
   In the
     >        > cylinder - CPVC maybe - I will have the fluid on the bottom
   and the
     >        > coolant line at the base with the air fitting at the
   top, but no
     >      piston
     >        > and no spring - rather a solid foam ball floating in
   the coolant
     >      with
     >        > only a few mm clearance between it and the walls. It will
   keep the
     >        > liquid from sloshing near the base and keep mostly air
   above it.
     >      Fail
     >        > safe in most modes of flight.
     >        > -dave
     >
     >
     >      Dave
     >
     >      You are joking right?  Plastic unless you are talking
   Teflon is not
     >      the best
     >      substance to hold up in a stressful environment like an
   aircraft
   engine
     >      compartment. I have lots of late night experience replacing
   CPVC
   of all
     >      grades in pool filtration systems that are subjected to
   expansion
     >      contraction cycles. The stuff micro fractures and is they
   are not
     >      apparent
     >      until sudden failure.  Ie one large crack. Hard foam
   abrades and
     >      ends up
     >      clogging the radiator.  Terrible for heat transfer
   characteristics:)
     >
     >
     >      Go with aluminum if possible. Lots of tested vessels on the
   market.
     >
     >      Doug in Japan
     >
     >      -----------------------
     >      Doug,
     >
     >      I was not going to use CPVC it does not have the right
   properties.
     >      does not support a high temperatures.
     >
     >      I can use any of the following, it is individual choice.
     >
     >      Steel wall thickness 1.0mm to 1.6 mm
     >      Aluminimum wall thickness 2.0 mm to 4.0 mm
     >      Plastic wall thickness approx 8.0 mm
     >      There a only couple of types on the market that suit.
     >
     >      The properties required for the right type of plastic are,
     >      high heat support at least (140 deg C)this rules most plastics
   out on
     >      the spot.
     >      high impact
     >      high pressure (this rules out most others)
     >      able to see into it (tanslucent at a minimum)
     >
     >      They are only a very few that meet these requirements.
     >
     >      So if you want metal thats fine the functions are exactly the
   same just
     >      the tube material changes.
     >
     >      Regards David Gaze
     >
     >
     >
     > Lots of (most?) modern automotive radiators have plastic tanks
   (on the
     > ends of the core).  There ARE plastics that will survive the
   temps and
     > pressures...
     >
     >
     > Matt-
     >
     > Yes but they are troublesome. It is automotive practice to use
     > a 15 psi radiator cap but most rotary powered aircraft are now
   using
   30 psi caps.
     > I see no advantage in plastic over aluminum for aircraft use.
     >
     > Paul Lamar ...No rotor no motor.


   There is always transparent aliminum!
   --
   Blake C. Lewis

   That is a new one on me. In fact I have never heard of
   aliminum let alone transparent aliminum :)
   --
   Paul Lamar ...No rotor no motor.

   ---------------------------
   Blake C. Lewis

   Yep I've got to see that :)

   Maye we could call "the startrek" and ask them for the formula or where
   to get it from! :)

   Regards David Gaze


Actually the problem (as I understand it) is that there's a rubber oring
which gets crimped between the tank and the core.  The oring eventually
deteriorates, and blows out.  No field repair strategy.  Not the fault
of the plastic.


Matt-

The plastic also cracks. I have a few rads around here to prove it :)