On / Off monitoring for butterfly valve

[dsg1985]

Simple question, I'm after a butterfly valve which transmits a signal or can provide some sort of indication when used of whether it's fully closed or not fully closed. Can anyone tell me where I could find one / what I'm after?

I'm after about 3" diameter, I'd like to place them below a water cannon, and use them to provide a safety start (i.e. if someone tries to start the water cannon's pump, and all 4 valves are not shut (using 4 cannons currently), the pump doesn't start causing one or more cannons to discharge water in a random direction).

Thanks.

 

[whammett]

Typically mechanical linkage to a valve positioner which is attatched to the stem will show the postion in a pneumatic flow control valve. You can buy some actuators that have associated pressure transducers. Once you program the controler to the given ranges, the controler in a digital system will show how open or closed the valve is.

HOWEVER, there is a major downside to this. It is using air or hydraulics, it does not actually go on the real position of the valve. It goes off of what the pressure transducer is telling it. If the valve is sticking or the controller is not calibrated right, it will give a false reading.

"Scientists dream about doing great things. Engineers do them." -James Michener

 

[dsg1985]

Thanks,

Is it possible (or common, anything is possible I suppose) to obtain manually activates valves with a binary indication of whether they're closed or not? I'm not interested in knowing the many positions of the valve between open and closed, just whether or not it is closed so the system knows whether it's safe to start the pump.

I wanted to avoid the cost of actuators and providing compressed air, if possible. I assumed something with a simple electrical switch might be common.

 

[whammett]

Sorry, I misuderstood you. Yes, its very common. Grainger has a line that we use in some of our plants.

http://www.grainger.com/Grainger/items/5MPP4?cm_mmc=Google Base-_-Plumbing-_-Valves-_-5MPP4

"Scientists dream about doing great things. Engineers do them." -James Michener

 

[DRWeig]

Google "whisker switch" (preferred) or "limit switch" for a whole bunch of options. You'll have to do some bracketry work to mount them, but they'll be reliable.

Good on ya,

Goober Dave

 

[dsg1985]

Thanks,

The valve linked and my searches led to limit switches for mounting on actuators and actuated valves with position indication. I was hoping for a manually actuated butterfly valve with position indication, is this very unusual?

 

[rconner]

[see also

http://eng-tips.com/viewthread.cfm?qid=271835&page=1

]

 

[DRWeig]

dsg -- yes, a manual valve with position indication built in (other than a visual) is pretty rare. If you want a signal (on / off or linear), you're pretty much stuck building your own as far as I know.

The only manual valves I see regularly with limit switches built in are OS&Y type gate valves for fire sprinklers. Even those are often add-on-in-the-field things.

If somebody else knows of a manual butterfly that comes with a monitoring option, I hope they post it -- might be a problem solver, eh?

Good on ya,

Goober Dave

 

[hsbcn]

Belimo offers actuators that can do this:

http://www.belimo.com.cn/pdf/GRVU_EN[05.08.2009UPDATE].pdf

My focus: Alloy Valves Duplex Valves Super Duplex Valves Monel Valves Inconel Valves [link titanium-valves.com]Titanium Valves[/url]

http://www.6-moly-valves.com

 

[itascot]

Use a manual gearbox operation, the position transmitter mounted on top (as for a actuator) will give local visual indication and transmit position to remote control room.
Try contacting flowbus

http://www.flowbus.com

(actuator and gearbox manufacturer) for fast delivery & good understanding of your requirements (they have dealt with this before...).
Ciao,

 

[JimCasey]

Yes it is somewhat unusual to mount switches on a manual valve, but not unheard of.

The major limit switch suppliers can provide this.
Since your valve operates a water cannon, then I presume it is (outdoors) and (2) subject to getting wet

You should get the switches in a NEMA4 (weatherproof) housing, unless this is a refinery where almost everything is in a NEMA7 (explosionproof) housing.

The leading switch manufacturers can all accomodate this request. It sounds as if you need 2 switches: One for Closed, One for Open.

Flowserve/Automax
Tyco/Westlock
Emerson/Topworx
ASCO
There are others.