Hydrostatic Testing for Pipelines: A Step-by-Step Field Guide

Hydrostatic testing verifies that a pipeline can safely withstand its design operating pressure. It also checks for leaks at joints, welds, and fittings before commissioning.

1. Isolate the test section with blind flanges. 2. Fill with clean water, purging all air. 3. Pressurize to 1.5× design pressure (minimum). 4. Hold for minimum 24 hours (as per spec). 5. Monitor pressure gauge — any drop indicates a leak. 6. Locate and repair leaks, repeat test. 7. Document test certificate with gauge readings.

• Ensure all pressure relief valves are functional before testing. • Clear personnel from test zone during pressurization. • Use calibrated gauges with recent certification. • For gas pipelines, water testing is mandatory before gas introduction.