DIfference in control valves & servo valves

B

Thread Starter

Beginner

Hi All,

I am a fresher and trying to learn things...so had a basic doubt..
As per my understanding,both control & servo valves can provide stepless control (in terms of percentage opening) and that servo valves are electrically actuated whereas control valves may be hydraulically or pneumatically actuated and so by this way servo valves may be faster...

But i have a confusion whether control valves has various types in terms of actuation where servo valve is one of them?

Please point out if something is going wrong with this understanding.

thanks in advance.
 
Servo Valve = regulating or modulating Valve + positioner
Control Valve = Valve for regulating or modulating duty

Positioner is a Servo Controller. It translates 4-20mA command into a proportional 0-100% opening of the valve stem.

Hope the above helps
 
Control valves have positioners, too. Servo valve is a type of control valve, but because it has different operating mechanism than other control valves it is generally referred as servo valve.

You need to understand op. principle of servo valve and traditional control valve, then you ll get it
 
Thanx for the explanation.

From this i understand that a servo valve is a control valve with feedback.
 
> Thanks for the explanation.

> From this i understand that a servo valve is a control valve with feedback.

Do you have an idea on how to actually stop a Servo valve at say 0.08m where 0.1 being the fully open condition?
 
W

why must i fill this in if i am loged in

> Do you have an idea on how to actually stop a Servo valve at say 0.08m where
> 0.1 being the fully open condition?

as general rule of thumb idea u can believe what has been said so far but it really so.... a control valve can have feedback too if u want.... u will find a servo valve costs a lot more than a control valve; even w/o any feedback. it is in its inherent design that allows it to MOVE open and closed MUCH MUCH faster than a plain ol control valve. then put feedback on it and u can get servo performance since it operates so much faster than a control valve.

I have no clue what your .08m (meters? minutes? microns?) and .1 no units question means.... restate?
 
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