Manual Valve (VB): Retrofit A Position Indicator??

This is a Pharma Plant application.

The Plant is highly Automated, but there are still many, many Manual Valves throughout.

Is it possible to retrofit a valve Position indicator (PI) to a Manual Valve (VB)?

The idea is to know whether these VBs are completely closed, or not.

The VBs are manually closed by Operators with a 90-degree turn (sometimes using a long handle for leverage).

We had an "event" recently (no injuries, thankfully), and I was subsequently asked if Automated Valves (XVs) could be added.

Well, when we thought about all the paths where these XVs would need to be added, it came to something like 40-50 valves! Not going to happen. After all ... 25 years ... and this was the first "event". It was really "Operator Error", but to me ... one "event" is one too many.

So I wondered if it would be possible to just add PIs to these VBs (just to indicate "fully-closed"), then use a "field PLC" to collect these signals and MUX them up to the DCS (which could then determine if pressuring up a Header, Config Station, or Loop was safe to do).

Some of the larger ball valves have places to mount an actuator. I have used these mounting locations to add mounting brackets for small proximity switches. We had a process years ago that relied on operators to place four manual ball valves into the proper positions based on what they were trying to accomplish. We didn't have money to add four automatic actuators, so we added switches. If they were not in the right position for what they were trying to accomplish, an alarm would sound and annunciate the wrong position.

I second the idea of prox sensors looking at the valve handles. I've done that before on small ball valves with good success. This will be fine for fully open or fully closed but won't capture how far it's open if it's partially open.

Most ball valves have either the brackets for mounting proxies & actuators they are usually part of the bracket where the handle fits, automating the valves sometimes means removing the brackets to fit the actuator mounting, if none of these exist then simple mounting brackets can be fitted for proxies to indicate open or closed. I have seen systems that only use one proximity mainly for closed (but occasionally open) this was done for reducing the cost, whether it had a proximity for open or closed was to indicate what was for correct operating position i.e. fullt open if on the outlet of a pump or fully closed if feed of steam etc. not ideal but better than none at all.

Great! So it's possible. I thought so. Had to be a less expensive way to do it short of wholesale valve replacement. I think all we'd need is "Fully Closed".

Thank you!

Yes that is correct, It will depend on the type & make of valve but most I have come across have a bracket thay mounts on two of the clamp bolts that hold the housing for the haldle, if it does not have mountings for position sensors it is usually quite simple to make a bracket, fit it by removing two of the screws & fit longer ones with the extra bracket for the sensor, many either have the sensor mountings or a bracket that can be replaced.

Yes, usually the adapter bracket is the tricky bit. I'm partial to Westlock position indicators, their local supplier may be able to help you with it.

Bear in mind that because of the handle the position indicator fixing seems a bit fiddly, but that comes with the application.

Check with your valve supplier. Most valves have kits available to retrofit open/closed limit switches. An example: https://assuredautomation.com/manual-valves/index.php?p=buy

One more question ... and now maybe I'm getting kind of greedy here ... but how about wireless? Is that an option ... or is this not acceptable (maybe even a hazard?) in a Pharma Plant? This place currently has ZERO wireless with its Automation. We *might* have one instance of wireless on a Retrieval System in the Warehouse, but that's not a "Process Area" ... and I'm guessing the reason is it could be unsafe in the Process areas?

Is it the "Class 1/Div 2" thing stopping this?

Not really, if you have proximities & other sensors that are not either explosion of safey rated then there is no problem, however I think that's going a bit far it seems you already have some connection to the upper level system can you not connect into that i.e. ethernet etc.

Colt Hero said:

One more question ... and now maybe I'm getting kind of greedy here ... but how about wireless? Is that an option ... or is this not acceptable (maybe even a hazard?) in a Pharma Plant? This place currently has ZERO wireless with its Automation. We *might* have one instance of wireless on a Retrieval System in the Warehouse, but that's not a "Process Area" ... and I'm guessing the reason is it could be unsafe in the Process areas?

Is it the "Class 1/Div 2" thing stopping this?

Click to expand...

You would still need to power them? Haven't seen a wireless solution for this application to date.

Colt Hero said:

One more question ... and now maybe I'm getting kind of greedy here ... but how about wireless? Is that an option ... or is this not acceptable (maybe even a hazard?) in a Pharma Plant? This place currently has ZERO wireless with its Automation. We *might* have one instance of wireless on a Retrieval System in the Warehouse, but that's not a "Process Area" ... and I'm guessing the reason is it could be unsafe in the Process areas?

Click to expand...

How critical is this valve? Do you trust a wifi router to tell you a valve is closed?

Colt Hero said:

Is it the "Class 1/Div 2" thing stopping this?

Click to expand...

If its a hazardous area, then yes.
You cannot install electrical devices, neither wired or wireless (thus storing energy) without said devices being approved for use in the area.
How are other sensors that are in the same area integrated into the control system ? If you dont know about hazardous areas, then you should stay away from this.

parky said:

Not really, if you have proximities & other sensors that are not either explosion of safey rated then there is no problem, however I think that's going a bit far it seems you already have some connection to the upper level system can you not connect into that i.e. ethernet etc.

Click to expand...

We have two levels of Controllers for our DCS, which is where these Switches would come in. The 1st level is actually the "Safety" Controllers, which are PAC8000 MTL (GE), but they also collect all the hard-wired I/O and MUX it back to the 2nd level (Process Control Logic) Controllers (via MODBUS). The 2nd level is a proprietary VME-chassis DCS system.

So ... I'm thinking we'd have to hard-wire these Prox Switches back to the MTL Controllers (as individual, Binary Inputs ... 40 of them, at least), then maybe compress these inputs into (4) Bitwords to minimize the I/O impact at the 2nd Level, since we don't have a lot of space left there. Since these Bitwords would arrive via MODBUS, I'm thinking I wouldn't have to worry about "dropped bits" (like I did when we wired a Rockwell ControlLogix PLC directly to the Proprietary DCS input ... that was kind of tricky, but I got it to work with a very bizarre range/scaling .. LOL!).

mad4x4:

Yeah ... power ... the wireless thing isn't possible, I guess. They'll have to be hard-wired just like any other Prox Switch we currently have in use.

cardosocea:

How critical? Well ... they've been Manual Valves for 27 years, routinely left wide open, without any issues because of more-experienced Operators, AND a Plant that ran only a few products in large batches for 20 of those years.

But now, it's another owner, with another business model, with multiple products, changeovers, etc. .. and, unfortunately ... less-experienced Operators. What used to be "routine", may not be so "routine" anymore ... hence ... maybe more protections need to be put into place that we didn't really need previously?

So I would say ... maybe these valves have *become* more "critical" (now)?

Would I trust a WiFi Router to send the Switch statuses? YES ... because it would err on the side of SAFETY: no signal ... means the Valve is assumed to be CLOSED, and no transfer starts up. But, unfortunately, I can't use WiFi in this environment.

JesperMP:

Yeah ... I kind of knew that ... "Class 1/Div2" puts the stopper on everything. Need "intrinsically safe" most of the time ... etc. So ... we'll just have to buy the "Approved For Use in Class 1/Div 2 Area" Devices, and hard-wire them like everything else ....

I wouldn't be doing this myself. Lots of people involved. I'm just exploring possibilities and suggesting a way to close this potential Safety "loophole" in the most economical way. They're not going to purchase 40-50 new Automated Valves ... so it's either this, or they just do what they typically do: emphasize Training and procedures (again) ... but humans will be humans, right?