more snips...
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.
----------------------------
Well one of the plastics I am looking at for those that want plastic tube
at the 8.0 mm wall thickness has a tyical 140 deg C sustained normal
operating temp.
over 300 deg C, pressure ratings in excess of 400psi, and some insanely
high impact resistance.
This should be more than suitable, The only thing that has not been
confirmaed is the chemical resistance
I'm waiting for the answer/s for the manufacturer, who siad they would
have to check and let me know in a
days, which normally maens about 2 weeks.
Regards David Gaze
The problem with most plastics is they heat age rapidly and become brittle.
That is why there are millions of cracked radiator tanks in junk
yards. There is no way the properties remain the same
after it ages for a few years. It is also what the manufacturers
of the plastics don't tell you about it.
Paul Lamar
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