hydraulic positioner
hydraulic positioner
(OP)
Has anyone ever used a hydraulic positioner for a control valve? Does anything exist?
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RE: hydraulic positioner
RE: hydraulic positioner
RE: hydraulic positioner
RE: hydraulic positioner
One of the more common servo valve manufacturers is Moog. Their servo valves are often seen married to third party cylinders from the likes of Rexroth, Vickers, Parker, etc, although they also produce their own cylinders. http://www.moog.com/Industrial/
Feedback to close the loop is usually from an LVDT or a magnetostrictive transducer on the cylinder, while the servo controller itself could be either an OEM product embedded within a larger control system, e.g. Emerson's QVP card for their WDPF DCS system, or a stand-alone item from the likes of Moog.
If you are looking for a self-contained package more akin to a traditional valve positioner, have a look at Rexa's offerings. If you give it electrical power and a demand signal it behaves much as a positioner. Failure modes to mimic OAF / CAF / stayput can be designed in as required. www.rexa.com
Finally, forum1083 is probably the best place for your question - get some advice from real pro's instead of me!
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Sometimes I only open my mouth to swap feet...
RE: hydraulic positioner
Servo valves have a faster reponse time and lower hysteresis than proportional valves. But if the system is closed loop and the position of the hydraulic cylinder is known, a good proportional valve will do the job.
It will just achieve the correct position slightly slower.
Adrian
RE: hydraulic positioner
Valcontrols from Denmark produces medium independent positioners for the oil and gas industry. See www.valtor.dk
- Control signal is 4-20 mA.
- Valve position feedback to positioner is 4-20 mA.
- Output is 2x 24 VDC (1 solenoid to open / 1 to close)
- Power supply is 24 VDC
M.v.h.
Terje
RE: hydraulic positioner
http://www.ccivalve.com/pdf/638.pdf
We use something similar from the BTG days which is reasonably good at its job. It lacks the finesse of the precision servos on the turbines but costs significantly less too.
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Sometimes I only open my mouth to swap feet...
RE: hydraulic positioner
The CCI Smartrak solution is as close as you can get to a "hydraulic positioner".
See link http://www.ccivalve.com/pdf/877.pdf for more info.
BR
Mathias
RE: hydraulic positioner
I'm an employe at Val Controls in Denmark. We manufacture and sell a lot of hydraulic positioners.
Our main focus is the oil and gas industry and in the oil and gas industry they use a lot hydraulic actuators.
We manufacture Hydraulic positioners for both Offshore, industry and Subsea. And are able to deliver positioners certified to EEx i or EEx d.
So if you are looking for a positioner for a hydraulic actuator, please give me a call.
Best regards
Carsten Toft
vc@valcontrols.com
Tel. +45 75470600