REFLECTOR:RE: Vernitherm as a Bypass Valve

Scott reflector@tvbf.org
Tue, 02 Dec 2003 20:31:41 -0700


Bob,

As I understand it, I've never cut one apart, a non-congealing oil cooler 
has a large orifice running through some portion of the cooler that allows 
the cold congealed oil to flow through it.  The veritherm/bypass valve 
that's on your accessary case allows a very small amount of oil to flow all 
the time(when its closed its not totally closed) .  This small amount of 
oil flows all the time, as it warms up it slowly warms up the cooler.  If 
the cooler is really really cold then when the veritherm valve opens the 
oil will only flow though the "wee-wee" hole in the cooler at first, slowly 
warming up the smaller cooling orifices right next to the flow and 
spreading out from there.

Thats how I understand it.

Some oil coolers have there own veritherm valve built in so you can run 
multiple coolers but only the ones that see hot oil will open up and cool 
the oil.  Is that what your talking about?   I've only seen these on 
automotive coolers.

The veritherm valve that is also a bypass valve that I am talking about is 
built into a housing that bolts to the accessary case and that's where you 
hook up your external filter/cooler lines.

Scott

At 06:30 PM 12/1/2003, you wrote:
>Scott,
>
>Can you please explain what a "congealing oil cooler is" and what was done
>to make them "non-congealing" in "modern" times?  Do the newer Vernitherms
>also function to bypass oil when the pressure is too high, as well as when
>the oil temperature is too cold?
>
>We have a Vernitherm in our engine oil cooler, but as far as I know, there
>is not one in the forward oil cooler or the "sandwich" that sends the oil to
>the forward cooler.  Therefore, you would think that oil congealing in the
>forward oil cooler could still obstruct normal engine oil flow, since the
>forward oil cooler is a part of a "serial" path coming out of the engine oil
>filter via the sandwich.
>
>A related point -- if it's the Vernitherm's additional bypass function that
>protects the normal engine cooler against congealing, although it would then
>allow oil to bypass the cooler, oil would no longer be cooling in the cooler
>and also the oil congealed in the cooler would be "out of service" and the
>effective oil circulating in the engine would be reduced by the amount still
>congealed in the cooler.
>
>I appreciate your insights -- sorry to bore everyone else to death on this
>subject,
>Bob
>
>
>
>-----Original Message-----
>
>"...No modern(later than 1965?) airplane has a congealing oil cooler on it,
>or
>maybe I should say, can't imagine any one actually installing one on a new
>airplane such as our homebuilts..."
>
>
>
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