> -----------------------
> 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 :)
--
Paul Lamar ...No rotor no motor.
-----------------------------------------------------------------------------
Paul -
Where did the cracks occur? I'm assuming it was at an intersection joint
like the hose or where the plastic to alloy connection occurs. After all if
they made them like a copper one with copper tanks they last 10 + years,
but weigh much more. The Plastic used by car manufacturers does not like
having side stress placed on it, particularly when it is under
pressure and heat. It is quite brittle, also quite thin, you should go
back and look at thickness.
Matt-
Yes there are 2 "O" rings
one at each end in the bottom of each "groove" machined into the alloy
plate.
It seals the tube to the end plates and ensures that the tube stays located
correctly for good. They are under compression average life expectancy in
excess of 5 years. Chance of leaking close zero. If that concerns you
that much
carry a spare or two. they are inexpensive. The spares stand a greater of
perishing before you use them. Or you change them at each annual just
for something to do.
I used this without any issues for over 2 years without any hint of a leak
I took it apart a couple of times just to have a look and changed them
each time but I could have reused them if I had really wanted to.
The modified design pics I send out yesterday or the day shows the
simplified
design. In a plastic one we would use a rather flat compression ring
rather than an "O" ring.
The tube in plastic would be at least 8.0 mm to 10.0 mm for those that
do not use metric
thats 1/3 of an inch of thicker. There are no joints or holes it is a
clean tube.
But as I have said more than once you can have either steel , or
aluminium as
well, the choice is yours. Just cannot see into a metal one directly.
so if you want to see in then an inspection glass needs to be installed.
Regards David Gaze
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