wrote: (clip) But I would suggest using something more
like a dead weight tester instead of air. (clip) The reason is stored
energy. Lots of energy with compressed air. (clip)
^^^^^^^^^^^^^^^^^^
If you have air available, and you know how, you can do it safely. Have a
small volume of air in contact with the water, connected to the supply
through a small orifice, or a nearly closed valve. If you get a rupture in
the test vessel, the pressure will drop, and air will only hiss from the
supply. (The danger from high pressure gas or steam exists only if there is
a substantial volume which can explode.)