>
       > 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 :)