This indeed harks back to the origin of the word "valve". A traditional (water) valve may be operated by the application of a few pounds of force, but may control the flow of thousands of pounds of...
Design pressure multiply by 1.1 equal pneumatic test pressure.Design pressure multiply by 1.5 equal Hydrotest PressureNote: Design Pressure is different from Operating pressure. Design Pressure is...
To test a pressurerized gas line apply soapy water to all connections.
You will see bubbles appear if there are leaks.
I see plumbers do this at the houses I work on.