What is an important step before filling for a hydro test?

Before conducting a hydrostatic test, checking for air in the system is a crucial step. Hydrostatic testing involves filling a pipeline, tank, or vessel with water to verify its integrity under pressure. If air is trapped in the system, it can compress and may lead to inaccurate test results or even dangerous situations during the test. Air pockets can potentially cause an increase in pressure during the test that could lead to bursting or failure of the system being tested. Ensuring that the system is free of air before filling helps to maintain safe testing conditions and accurate pressure readings.

Other meaningful steps, such as notifying the safety officer, confirming the test pressure, and inspecting valves and fittings, are important to the overall preparation for the hydro test. However, they are more about ensuring overall safety and compliance, while checking for air specifically addresses a critical aspect of the testing process itself that directly impacts the reliability and accuracy of the test outcomes.