On Off Valve Actuator Selection

The simplest way would be to run a control signal only from the control point to the approximate location of the valve, pick up power from a source close to it, and combine the two in some sort of relay box in that location. The control signal could be simple digital output signals, or via a data link, or even via radio-telemetry. Without seeing the installation it is difficult to suggest more.

Thanks for your answer. The problem is that the closest power supply to the valve is that 1.5 Km far, because the valve is located in a remote platform above water without electric supply. So I'm thinking to use pneumatic/hydraulic piston actuator for this application. Is it possible to use pneumatic (probably piston type I guess) actuator capable to handle 24" ball valve?

Regards

It's possible provided the long response time to the control output can be tolerated. Whatever its size, it is going to take some time to raise the pressure at the far end of a pneumatic line 1.5km long sufficient to turn the motor on a 24" valve. The speed of sound says that it is not possible to cover that distance in less than about 5 sec, for example, and then the actuator cylinder needs to charge up, etc., etc.

One might put the kettle on while the valve opens. Milk? Sugar? One or two?

If that's a gas line you're working with, and the pressure in the gas line is high enough, you can use it to power a pneumatic actuator. Then, all you need is a solar/battery-powered switch and a wireless connection.

Running natural gas through a pneumatic actuator is easy, but it requires an I/P that can work with natural gas. Here's one http://www.miinet.com/Portals/0/PDFs/IP_for_Natural_Gas.pdf

and here's a story I wrote way back when I worked there

http://www.miinet.com/Portals/0/articles/WhatsNewinProcessTech_4-2007.pdf

Sir, As mentioned by other members, you have chice to use the gas as motive force, combined with digital signal from your remote scada, with a solar pwer backed ups system to operate this remote valve. if it is a critical valve like emergency shut-off valve , fail safe control logic to be applied. if it is going to be operated from remote on manual command it is different. We are now istalling a GOV in our gas line which is 24 inch size. The valve is 8 Km from the control room. We are installing solar power ups system to operate the valve, using the natural gas as motive force. For solar power supply panel you need sufficient place to install the panel, battaries, control units etc.

Thanks for the answers. Natural gas inside pipe was purposed before as a replacement of instrument air, but what I see is that (might be wrong), the pipe line is used only during emergency for venting hydrocarbon (PRV header line, BDV header), so the fluid inside it cant be used as instrument air replacement, I guess. My friend tells me that nitrogen bottle will be used instead of hydrocarbon gas in the pipeline, and it will be installed near the valve with new support, etc. Instrumentation cable runs from nearby control center (300-500m, approximately), and hence no scada needed. However, this arrangement still not clear for me. Any suggestions?

Regards.

Yep. Hire a consultant locally to look at the proposed arrangement and design something suitable.

You could use pneumatic, if you locate a storage tank(Receiver) close to the valve with a check valve preventing it from discharging back to the source of the air supply.This would allow the tank to charge to full system pressure, and provide adequate volume and rapid response time for operating the valve.As long as the storage tank size is large enough to accommodate the duty cycle of the valve,and supply line is adequate, the response time should be acceptable.Of course, control of the valve should be electrical or RF to eliminate lag time on signal end of loop.Operation of local solenoid requires very little current, so voltage drop would be minimum,especially if a properly sized and rated capacitor is located at the valve end controller to provide inrush current to the solenoid coil.

there're such stuff also avail (usually the less components the less prone to error)

what's wrong with the optical cable (why pneumatic, radio, electrical wires )

Please tell how you can make those photons open a valve.

The pneumatic does the actual physical work of operating the valve body, the electrical power does the signaling and/or control,and the radio is an alternative signaling method.

Optic cable could also be used for signaling as well,but a power source for physically moving the valve is still required:(pneumatic or electric).

(i dont'make ashit) not been on a feeld for years 1,2,3,4,5,6 ?? somewhat so - i thought they only use optics for nowadays - but it's still a BIG NEWS _{just like an article in http://www.ncbi.nlm.nih.gov/pubmed/17789445 (i gess that one) or it's clone in SciAm - where tay said C-n-Tube Displays on amarket after 12-15y (~2010) - and then the very same stuff was A BIG NEWS 10y from that (then they didn't proposed any purchase dates) in sciencedayly.com}

- me cant be taken very seriously - i'm just a sci-fan - not enything certified

. . . . . . . . . i donno this kind of stuff gets me really pissed - it was back in 1998 when i worked as production datasets tech. - we had our clients system backed up in our laptops so they called 1AM we booted up looked up their stuff - said do1 do2 and went back to sleep - we'd trained/convinced our customers to leave their msg on a mobile phone voice mail (back in 1998) . . . the mobile type office became a more global trend some y later 2000+

it's g.d. 2013CE - and there's still difficulties integrating "innovations" - i donno

you just want to do something and you do it so

or then you don't and you keep seeking the exuses

https://www.google.com/?q=autonomous+remote+controller+industrial+-wireless

revealed

https://mining.cat.com/command

usually the search "mars atmosphere" doesn't reveal a sh¡t

but search "tribo electric lift atmospheic opacity" might be more practical