Tubular bumper as OBA tank

[dustboy]

I'm sure you've heard of guys plumbing their tubular bumpers as OBA tanks..I built my rear bumper out of 4" x 4" x 1/8" square steel, and granted I could find all the holes and plug them, would it be a great or horrible idea to do this? A quick calculation gives me about a 4 gallon capacity.

Would the square steel bulge under pressure?

 

[spencyg]

not a problem until your bumper comes in contact with something at enough velocity to puncture it...then it will make a loud noise, and scare people, and you'll have to do fix it. Other than that, yes...people have been doing this for a long time without issue. Just make sure you provide a good drain port as well as a pressure relief...no point building a bomb on the front of your truck....

 

[FlatlinesUp]

usually only going to see 100-125psi, so no buldge

folks will be quick to jump on "when hit, it'll explode!!!!", more likely it'd crack and vent the air if anything, not "blow up" as once again 125psi vs 1/8" thick steel the 1/8" wins.

I think it's a good use of space and if you design it correctly (petcock to drain moisture, moisture trap between compressor/tank, etc) then you'll be golden and ahead of the curve

nice looking bumper, got more pics?

 

[ntsqd]

ASTM codes for air receiver tanks generally start with tanks used at a minimum of 125 psi. Professionally built air tanks are round with rounded ends, without exception, for a very good reason. I wouldn't go as far saying that it will explode if you hit it hard enough, but the possibility for shrapnel does exist.

This is one of things where just because it hasn't happened yet doesn't mean that it can't or won't happen at some unpredictable time in the future. Lots has been learned by folks in the past, sometimes at an extreme price, about how to build things put under pressure. It behooves anyone building such a thing to pay attention to those lessons and learn from them.

 

[dustboy]

Hard to imagine 120 psi deforming the steel, and I'm pretty sure if it did fail it would be a small crack that would release the pressure quickly. With a lot of noise..

nice looking bumper, got more pics?

thanks, take a gander:

here's a link to the build pics

It's changed a bit since the build pics, I added the 2" receiver, and the shackle mounts had to change, I notched them out and welded on big 1" nuts. I would never powder coat any of my modifications for the simple reason that they never seem to be quite finished...