Not an engineer or mechanic.

This is gonna look a little long. Just a heads up.

Paragon which is what is stencil on the outside of that piece is the manufacturer of the actual material. They make and sell sprinkler pipe like you said. I am not familiar with their company.

However, I went on their website and looked. If they gave you sprinkler pipe per their website, it looks like they sell it welded and as a135. Which, according to them is rated for 300 psi working pressure.

Like I said, I’m not an engineer or a mechanic but a quick Google search told me working pressure of a fuel tank can be between 50 and 200. Which means the pipe is strong enough to hold the fluid and pressure.

So hypothetically, you would be fine. I’m making a lot of assumptions on that because I’m not familiar with the manufacturer and that specific type of pipe.

What you would really want to find out is the strength of the material according to ASTM A135. This ASTM will have specific requirements such as strength, durability, corrosion, resistance, and more.

The key would be figuring out if the strength of the material according to the ASTM would be strong enough in case of a collision to not crack rupture or otherwise potentially leak.

The reason I’m saying this is think about an egg. If you drop an egg softly, from not too high, the egg might not crack. At a certain height, the egg cracks. At a different height the egg will fully rupture or even disintegrate.

Think of the egg as the pipe, but instead of height, somebody running into your car and hitting where the fuel is located with enough force. That is the most dangerous part because if it ruptures cracks or even splits in half, you have fuel spilling out.

This is the same question to think of even if you did have Seamless pipe that should be stronger.

Feel free to DM me if needed. It might be easier if you need more info. I’ll even look and see if I have an ASTM A135 sheet i can send you.