exploding plastic storage tanks

[AllenGregoryIV]

Originally Posted by Jon Stratis

I would agree... however the case I saw up at LSR (and prompted me starting this thread) was not due to a manufacturing defect - it was due to improper use and handling by the team.

From what I've seen of plastics in general, I'm not aware of any that could be use in this application that wouldn't have a similar failure mode. Then again, I'm a software engineer and not a chemist or material scientist. Still, it worries me.

I understand that point, I also understand that we need to better train teams to the dangers of pneumatics and for them to properly care for their equipment. The team in this case was operating illegally since the screw had to damage the air tank and thus modify it. There is a reason for this blue box in the manual.

Do not, for example, paint, file, machine, or abrasively remove any part of a pneumatic COMPONENT – this would cause the part to become a prohibited item. Consider pneumatic COMPONENTS sacred.

My point is that the PneuAir tanks have been in use on FRC robots longer than the Clippard tanks and I have never (doesn't mean it hasn't happened) heard of one of them failing do to misuse or defect.

[Paul Copioli]

Originally Posted by AllenGregoryIV

My point is that the PneuAir tanks have been in use on FRC robots longer than the Clippard tanks and I have never (doesn't mean it hasn't happened) heard of one of them failing do to misuse or defect.

^this.

We have also used the pneuaire tanks with absolutely no failure. What would be nice is if anyone has experienced a failure with the pneuaire tanks that they share their results here.

I think we should not over react. We should also make sure tanks are agency approved before they are competition legal.

Paul

[wilful]

I think that people are being too quick to assume that user error is the end of the cause of the failures. I have yet to see someone ask why this user error is occurring.

After pondering this, it does seem to be a design flaw. Likely this design flaw is in the documentation and the lack of safety knowledge. If there is a danger caused by stress from over-tightening the threaded fittings, there should be a sticker around the fitting that warns against over-tightening. The same should be true for any other safety issue with any device.

Also for any COTS device, read the manual before use. While the device may not pose an imitate safety hazard from a user failing to read the manual, reading the manual for the product will increase safety while using the product and prolong the life of the product.

[Mark Sheridan]

Originally Posted by wilful

I think that people are being too quick to assume that user error is the end of the cause of the failures. I have yet to see someone ask why this user error is occurring.

After pondering this, it does seem to be a design flaw. Likely this design flaw is in the documentation and the lack of safety knowledge. If there is a danger caused by stress from over-tightening the threaded fittings, there should be a sticker around the fitting that warns against over-tightening. The same should be true for any other safety issue with any device.

Also for any COTS device, read the manual before use. While the device may not pose an imitate safety hazard from a user failing to read the manual, reading the manual for the product will increase safety while using the product and prolong the life of the product.

In any case we need to gather more info and be careful until we know for sure whats going on.

I am using the 2013 clippard tanks, I thought its failure mode was user error too. Am I mistaken, was there a product defect that lead to its recall?

[wilful]

Originally Posted by Mark Sheridan

I am using the 2013 clippard tanks, I thought its failure mode was user error too. Am I mistaken, was there a product defect that lead to its recall?

I do not believe that there is a mechanical flaw with the design, just a lack of world knowledge which led to improper use.

[team222badbrad]

Originally Posted by wilful

I do not believe that there is a mechanical flaw with the design, just a lack of world knowledge which led to improper use.

Or lack of instruction/documentation included with the product?

[wilful]

Originally Posted by team222badbrad

Or lack of instruction/documentation included with the product?

The only problem with simply including documentation is that likely only one person will read the documentation and some people will think they do not need too. This is especially important with temperature issues and material safety.

[MrBasse]

You don't get safety information provided on a sticker on any other pneumatic components. If I crank a cast iron fitting into a stainless steel tank to far the tank won't hold air anymore, but there is no warning for that. I have yet to buy a cylinder that came with documentation about anything. Everything is online if you want it. Clippard had installation instructions on the product page that specified the torque for fitting to seal the connection. When FIRST posted this:

Clippard recommends using 2-4 layers of Teflon tape and tightening the ¼” NPT fitting to 10-12 inch pounds (do not to exceed 15 inch pounds).

last year they didn't make it up, it came from the instructions Clippard provided.