How does a variable orfice tube work?

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How does a variable orfice tube work?

Postby huntindog » Sat May 21, 2016 11:56 pm

I am about to do another 134A conversion. This time on a 1985 Chevrolet K20, I am wondering about using a VOT. I notice that there are at least two types. Over 105, and under 105.
I am in Phoenix, but the truck travels to the high country a lot... Will the over 105 OT give good performance? Just how does it work?

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Re: How does a variable orfice tube work?

Postby GM Tech » Sun May 22, 2016 2:28 am

Not worth it- IMO, you may get a half a degree better- but have seen them "stick" and cause more trouble then they are worth.

They "vary" the refrigerant flow amount (size of orifice changes) theoretically based on temp and pressure of refrigerant.
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