Why water pipe is not recommended for cannon barrels

[GGaskill]

Wrought Steel Pipes - Bursting Pressure is a page with some numbers on pipe strength.  The bursting pressures listed are from calculation using Barlow's Formula, not actual destructive testing of real pipe sections, so I don't know how close to reality they are.

Even though some bursting pressures seem adequately high, remember we are not trying for designs that burst but designs that don't burst.  And constant pressure from water is a completely different horse than transient pressure from confined explosions.

[mcwoodduck]

Most city water pressures are around 85psi, 150 PSI at best.  The relief valves on water heaters or boilers is only 125 PSI and that water can get to 230 degrees F. ( Greater than 80 PSI and the water will not flash to steam at that temp.)
All sewage pipe is atmospheric, 0 Psi
The large diameter pipe has high bursting pressures so it will not collapse when burried not because the water has that much pressure.
Sorry Boiler guy and I sold pipe for a while.

[BoomLover]

Can this info be forwarded to "Cast Boolits" forum, or, do you think with all the comments that have already been sent, they got the message? BoomLover

[Double D]

Yes it could be posted on Cast Boolit's, but I think the guy got the message already.

[GGaskill]

If you read the tables, you will note that small diameter pipe has higher bursting pressures than the larger stuff.

[Cat Whisperer]

Can this info be forwarded to "Cast Boolits" forum, or, do you think with all the comments that have already been sent, they got the message? BoomLover

It could be.  BUT if he hasn't gotten the message from what folks followed up with he won't get the tables either.

Cannons/mortars are different in application from water pipes/tubing.  It is the repetitive spike of pressure that incrementally hardens the bronze/steel/iron/(mystery metal) and the corrosive nature of the products of combustion that over time create the bomb.

[Victor3]

Cannons/mortars are different in application from water pipes/tubing.  It is the repetitive spike of pressure that incrementally hardens the bronze/steel/iron/(mystery metal) and the corrosive nature of the products of combustion that over time create the bomb.

 Yes.

 Even if we calculate a lightly constructed barrel to be safe now, what might the condition of the material be after 80 years? These little cannons we make might not be tossed in the trash or used as bookends after we pass.

 Do you want your grandkids firing a 'marginally safe' cannon that you made?

 Best to use proper material and overbuild to avoid a disaster who knows when in the future...