In hydrostatic testing, what medium fills and pressurizes the vessel?

In hydrostatic testing, what medium fills and pressurizes the vessel?

• A. Air
• B. Oil
• C. Gas
• D. Water

Answer: (C)

In hydrostatic testing, the vessel is filled with a liquid and then pressurized to check for leaks and structural strength. The usual medium is water because it is essentially incompressible, which means pressure readings reflect actual stress on the walls and leaks show up clearly as water escaping. Water is safe, inexpensive, and easy to drain and inspect after the test, making it practical for validating that the vessel can withstand the intended pressure without failure. Gas, on the other hand, is used for pneumatic testing, where the medium is air or another gas; compressibility and energy release in a gas test introduce different hazards and measurement considerations. So, the medium used to fill and pressurize the vessel in hydrostatic testing is water.

In hydrostatic testing, the vessel is filled with a liquid and then pressurized to check for leaks and structural strength. The usual medium is water because it is essentially incompressible, which means pressure readings reflect actual stress on the walls and leaks show up clearly as water escaping. Water is safe, inexpensive, and easy to drain and inspect after the test, making it practical for validating that the vessel can withstand the intended pressure without failure. Gas, on the other hand, is used for pneumatic testing, where the medium is air or another gas; compressibility and energy release in a gas test introduce different hazards and measurement considerations. So, the medium used to fill and pressurize the vessel in hydrostatic testing is water.