The valve in question relieves pressure on a container so the container can be opened for inspection.

Employees have forgotten to close the valve after buttoning the container back up. The results have been expensive spills.

Any thoughts on how to error-proof this operation?

Opening the container is not frequent, nor is it routine.

Thanks

Can you install a valve that has to be held open, but closes on its own if let go? No one will have to remember to close it then.

Not sure what kind of container you are talking about, or exactly what "buttoning up" entails, but could you put some sort of "indicator" (you know the little round things that hang from your mailbox once the letter carrier puts your mail in the mail box) that would be very visual, or a sign on the container that is visible upon closing it? A checklist would be a last ditch effort because it adds a step, but maybe there is already a checklist for your inspection? I'm sure you'll find someone who actually has some idea of what they are talking about, but hey, I gave it a try:biglaugh:

Wire in a switch that is open if valve is open and does not allow actuating the fill portion for the container if it is open.

(Long shot without knowing more about the process)

SteelMaiden,

I like the way you're thinking. :thanx:

The container's a vertical cylinder about 24 inches in diameter. The valve in question comes out of the center of the top.

There are captive bolts around the periphery of the top.

To look inside, you loosen the nuts on the captive bolts and swing them out of the way. The top has a hinge which allows it to pivot up and a counterweight so it doesn't slam down on your head while you peer inside the cylinder.

To close it all back up, you push the lid back down, swing the captive bolts back into position and tighten the nuts.

Then (if all goes well) you remember to close the relief valve and restart the process.

Can you install a valve that has to be held open, but closes on its own if let go? No one will have to remember to close it then.

Wire in a switch that is open if valve is open and does not allow actuating the fill portion for the container if it is open.

(Long shot without knowing more about the process)

Both excellent ideas. Thanks, Howste and Duke.:thanx:

Not to impose further :notme:, but how about an idea we could implement for a cost ranging from free to cheap?

SteelMaiden,

I like the way you're thinking.

The container's a vertical cylinder about 24 inches in diameter. The valve in question comes out of the center of the top.

There are captive bolts around the periphery of the top.

To look inside, you loosen the nuts on the captive bolts and swing them out of the way. The top has a hinge which allows it to pivot up and a counterweight so it doesn't slam down on your head while you peer inside the cylinder.

To close it all back up, you push the lid back down, swing the captive bolts back into position and tighten the nuts.

Then (if all goes well) you remember to close the relief valve and restart the process.

Yeah, get one of your people who like to come up with wild and crazy ideas to create something that pops up, or out, when you swing the roof (or open the valve), and then you have to "tuck" back into the "firing" position when you have the valve closed. Yeah, that's the ticket! Just be sure it doesn't spring too far, too fast and create a safety hazard, lol!

Lock out-tag out on the valve to turn back on.

Since the tank has pressure there should also be a torque spec. for the bolts. Who documents this spec is met?

Also maybe a pressure cutoff switch if the pressure drops to the tank. Linked to a shut off to the input of the tank.

Both excellent ideas. Thanks, Howste and Duke.:thanx:

Not to impose further :notme:, but how about an idea we could implement for a cost ranging from free to cheap?

Does the valve have to be open when you open the lid? Or can you open it and close it, then open the lid?

If the valve can be closed again before you open the lid, maybe you could attach something to the valve handle that interferes with one of the nuts if the valve is open. That way you would have to close the valve before you opened the lid.

Does the valve have to be open when you open the lid? Or can you open it and close it, then open the lid?

If the valve can be closed again before you open the lid, maybe you could attach something to the valve handle that interferes with one of the nuts if the valve is open. That way you would have to close the valve before you opened the lid.

Excellent point. It can be closed after the pressure equalizes with the atmosphere.

Thanks again. It seems we have the creative juices flowing here.

I appreciate it.

Lock out-tag out on the valve to turn back on.


Thank you. Excellent thought.

I may suggest a quick connenctor as one used for oleodinamic.
The female, self closing, on the tank, the male to be inserted to release the pressure attached to a necklace given to the operator. attached to the necklace there is also the pen the operator has to use to sign on the report form after maintenance. well may be it is too hot and my mind is going crazy sorry

I may suggest a quick connenctor as one used for oleodinamic.
The female, self closing, on the tank, the male to be inserted to release the pressure attached to a necklace given to the operator. attached to the necklace there is also the pen the operator has to use to sign on the report form after maintenance. well may be it is too hot and my mind is going crazy sorry
Grazie. Buona idea.:thanx:

Granted an engineering fix would be "best", but have you considered a reminder sign? A signoff sheet on the tank similar to those for fire extinguishers? A procedure checklist?

Does the valve fixture end up getting tipped up with the cover, or does it stay flat? Even a little rule like having the worker put an inverted cup over the valve fixture when it is opened, then they see the cup when they are done. Granted the employee must remember to put the cup over the fixture when they open it. Or perhaps vice versa - the cup is there when the fixture is closed and removed when open.

Granted these still rely upon worker action, but little things like this work like strings on a finger to aid in memory.

One late thought - as a cheap engineering fix - can a pin or lock be engaged on the valve when it is shut that must be removed in order to open the valve? The disengaged pin or lock would be a visual clue that the valve was left open.

Granted an engineering fix would be "best", but have you considered a reminder sign? A signoff sheet on the tank similar to those for fire extinguishers? A procedure checklist?

Thanks. I'll put those thoughts on the list.


Does the valve fixture end up getting tipped up with the cover, or does it stay flat? Even a little rule like having the worker put an inverted cup over the valve fixture when it is opened, then they see the cup when they are done. Granted the employee must remember to put the cup over the fixture when they open it. Or perhaps vice versa - the cup is there when the fixture is closed and removed when open.
It tips up.

One late thought - as a cheap engineering fix - can a pin or lock be engaged on the valve when it is shut that must be removed in order to open the valve? The disengaged pin or lock would be a visual clue that the valve was left open.This could be done.
:thanx:

The valve in question relieves pressure on a container so the container can be opened for inspection.

Employees have forgotten to close the valve after buttoning the container back up. The results have been expensive spills.

Any thoughts on how to error-proof this operation?

Opening the container is not frequent, nor is it routine.

Thanks

Install an electronic sensor on the pressure relief valve that prevents the other valve from activation when the relief valve is not closed.

Stijloor.

Install an electronic sensor on the pressure relief valve that prevents the other valve from activation when the relief valve is not closed.

Stijloor.

Thank you--good idea.:thanx:

How about something in the price range of free to cheap, if I may be so bold.;)

Thank you--good idea.:thanx:

How about something in the price range of free to cheap, if I may be so bold.;)

Cliff,

You would be surprised how "affordable" wireless electronics are.

I guess that what you would need may be available at Radio Shack. :)

But I must admit that I am absolutely not an electronics person....

Keep us posted, because I am very interested in Error/Mistake Proofing devices.

Stijloor.

Lock out-tag out on the valve to turn back on.

We came across these kinds of issues constantly in aviation fuel transportation and storage systems. For cheap and effective I would agree the lock out tag out system is a good option and will work well with a conscientious staff.

For consistent problem areas that need to be accessed routinely I would suggest putting some money into the system by utilizing a self closing valve Such as this (http://www.grainger.com/Grainger/items/1CKF4).

Visual indicators are always good as well, prominent valve handles, prominent labels for open/close. Additionally you could have the operator check the valve position visually as part of their startup routine on the process.

Another option would be to plumb the discharge from this valve into a containment tank with an overfill alarm.

If it were me I would add a clip so that the valve can be locked into the closed position and require that it be kept locked unless under maintenance. This would be an inexpensive option and a technician is less likely to forget to close the valve if they have to walk away with a lock in thier hand to do it.

Would it be possible to reset the valve by closing the lid? That would provide you with equipment ready to run as soon as you are done, and nobody would have to remember anything.

/Claes

I know you said:How about something in the price range of free to cheap, if I may be so bold.;)

But a valve such as this:
...I would suggest putting some money into the system by utilizing a self closing valve Such as this (http://www.grainger.com/Grainger/items/1CKF4).

Has got to be cheaper than even one spill...

Manually actuated pressure relief valve?
It protects from an overpressure condition and also has a manual pull that closes when you let go.

My company makes pressure relief devices.

PM me and we can swap details.

We came across these kinds of issues constantly in aviation fuel transportation and storage systems. For cheap and effective I would agree the lock out tag out system is a good option and will work well with a conscientious staff.

Yeah. I like the human factors aspect, as you point out later in this thoughtful post.

Thank you.

Would it be possible to reset the valve by closing the lid? That would provide you with equipment ready to run as soon as you are done, and nobody would have to remember anything.

/Claes

The mechanics might get a little hairy, but I like the idiot proof aspect.

But a valve such as this:

Has got to be cheaper than even one spill...

Yep, by a factor of about 200:1.

Yep, by a factor of about 200:1.

Cliff,

Have you narrowed down your options?

I am (still) very curious what you will do.....

Stijloor.

Cliff,

Have you narrowed down your options?

Not yet.

We're using this as a teaching moment and I have a session scheduled with the client on Monday the 7th.

I'll let you all know how we do when it comes to getting past the "human error" and "retraining the offender" syndromes.

Cliff

Not yet.

We're using this as a teaching moment and I have a session scheduled with the client on Monday the 7th.

I'll let you all know how we do when it comes to getting past the "human error" and "retraining the offender" syndromes.

Cliff

Thank you Cliff!

I know that many of us are anxious to learn about the outcome.

Stijloor.

I know that many of us are anxious to learn about the outcome.Yes indeed. This is exactly the kind of discussion that epitomizes the Cove: Helping each other help ourselves by mutual learning. :agree1: Everyone involved benefits! :D

/Claes

SteelMaiden,

I like the way you're thinking. :thanx:

The container's a vertical cylinder about 24 inches in diameter. The valve in question comes out of the center of the top.

There are captive bolts around the periphery of the top.

To look inside, you loosen the nuts on the captive bolts and swing them out of the way. The top has a hinge which allows it to pivot up and a counterweight so it doesn't slam down on your head while you peer inside the cylinder.

To close it all back up, you push the lid back down, swing the captive bolts back into position and tighten the nuts.

Then (if all goes well) you remember to close the relief valve and restart the process.

You may install a buzzer with two way switch. Mount one contact at the relief valve and the other one on the lid (in the closed condition). The switches are installed such that the buzzer is 'OFF' in this situation. It turns 'ON' the moment pressure at the valve is relieved, and again switches 'OFF' when lid is opened. Lid falls back and the switch is turned 'ON' and the buzzer will now be silenced only when the relief valve is closed or reset.

Hope this also falls in Free to Cheap category.

Umang :D

For legal compliance, the client has line-breaking procedures in place. The procedures require completion of a line-breaking permit before disassembling any part of the processing line.

They have decided to attach a checklist to their line-breaking permit. The checklist will include a reminder to close the valve.

Thanks to all for your thoughts, contributions, input and interest.

There are several suggestions here that I am going to ask them to consider as low-cost fail-safes to go with the checklist. I will update this thread with any changes.

For legal compliance, the client has line-breaking procedures in place. The procedures require completion of a line-breaking permit before disassembling any part of the processing line.

They have decided to attach a checklist to their line-breaking permit. The checklist will include a reminder to close the valve.

Thanks to all for your thoughts, contributions, input and interest.

There are several suggestions here that I am going to ask them to consider as low-cost fail-safes to go with the checklist. I will update this thread with any changes.

Hello Cliff,

Can you fill us in about changes that you have implemented?

Stijloor.