Anyone know if it is possible for a control valve to fail while driving the car causing loss of control of the car

 Depends on the mode of failure. If it simply craps out, you could have no power steering, but you could still steer the car.
The only other failure I can think of would be an out-of-adjustment issue where it could tend to "pull" the steering in one direction or the other. Usually, this will show up as soon as you start the car.
Of course, there's always the possibility of a mechanical failure, such as the ball stud coming out of the valve and leaving you with no steering at all, but....I've never heard of that happening on a PS car.

Is there some specific reason you ask this question?

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Joel Adams
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Thanks for the input when I started the car after setting over the winter the steering wheel turned very fast to the left replaced a faulty control valve balanced it everything is working fine I was just wondering if this valve could malfunction while driving and cause a problem