I'm not arguing strength, what you may not be considering is failure mode.

A pipe that throws chunks at high speeds is a much less attractive option than one that only cracks or splits but remains in one piece.

Also air under pressure is a lot more dangerous than water, air pressure is stored energy, hydraulic pressure (without air) is not so much...

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-