[JamesCH95]

Here is statement from the Plastic Pipe Institute: http://plasticpipe.org/pdf/recommend...ressed_gas.pdf

Notably:

The Plastics Pipe Institute recommends that thermoplastics piping intended for the transport of compressed air or other compressed gases should be installed by burial, encasement in shatter resistant material, or other appropriate means, to prevent or minimize the possibility of mechanical damage.

PP is a thermoplastic. Seems like a bad plan to use PP tanks from the get-go.

Originally Posted by Daniel_LaFleur

Allen, I understand where you are coming from but as someone who has had a 1 liter PVC pneumatic volume explode within 1 foot of me (thank goodness it blew out away from me) I will respectfully disagree here.

The dangers to anyone near one of these if it explodes, especially to bystanders, some of which may be children, is too high for my liking. Thus I say 'ensure it is safe and then we can use it'.

To the best of my knowledge PVC is not rated by any organization to contain compressed gases. Any use of PVC to do so is at your own risk and against industry practices.

Originally Posted by Lil' Lavery

This isn't about whether or not these tanks are quality products, it's about risk. Even if the failures are 100% caused by "user error," the tanks' failure mode is an explosion that sends shard traveling at high speeds. There are two attributes to risk, probability and severity. While we obviously don't have access to FIRST's safety risk matrix, I know that regardless of how low we drive the probability of the risk, the severity is still to high for these tanks to be acceptable for use on 1712 (and I would hope other teams). I feel much more comfortable using a tank with a failure mode that doesn't involve high speed, sharp projectiles.

Exactly!

Originally Posted by cgmv123

The tanks themselves are perfectly safe. It's using them properly that's the issue. Putting stress on the tank increases the likelihood of it bursting.

The plastic tanks are not what I would call "perfectly safe." They are safe when used in exactly their prescribed manor with little room for error. They are not robust or fault-tolerant. Some of these tanks will go to teams where no mentors or students know how to properly handle them, and FIRST has no way to stop this until the robot is at an event.

Originally Posted by Dave Campbell

Isn't this the purpose of FIRST? To teach, read inspire, students about the forces and how to use the tanks properly? Each team should find a Fluid Power Engineer or a mentor properly trained in the safe use of pneumatics, or at least follow the manufacturer's instructions for safe installation and use of the parts.

Of course, I don't want any person injured from mis-use or improper installation, so there must be some adult involved in the process. A key tenant of FIRST - students need mentors!

They should, but not every team will.

When inspecting our robot's pneumatic system this year our ERF was slightly out of adjustment and only started venting at ~140psi. The plastic tanks are rated for 125psi (the average Clippard metallic tank is rated to 250psi). If our robot had these tanks, they would have been subjected to pressures outside of their rated range. I wonder how many teams this has happened to...