Penstocks can be further subdivided into:
The test-method according to the Austrian standard B 2538 / EN 805 should be used.
However, for drinking-water pipelines, you have to use drinking-water as pressure test medium.
Important is the venting of the pipeline before the pressure test !!!
How you properly ventilate will show you our examiner on site.
The new Austrian standard for proof of tightness and stability by means of pressure testing of water-bearing, new and existing penstocks.
This Austrian standard applies to all pipe materials.
These are special penstocks in which the water isn't transported to the destination by overpressure, but is sucked in from the target with a vacuum pump.
They are very rare because they are expensive to build and to check.