Does the system hold? The water answers — and we document it.

The line or vessel is filled with water, pressurised to a defined test pressure (commonly 1.5× working pressure, or the figure the governing code or spec sets), then isolated and held while pressure is monitored over a set period. A stable reading proves the system holds; a measured pressure drop proves it doesn't — confirming a leak exists and quantifying how serious it is. It's the pass/fail integrity check that commissioning, codes, and warranties rely on, and the objective confirmation step before or after pinpoint detection.

Most commonly at three moments: commissioning new pipe before it goes into service (water mains to AWWA practice, fire lines to NFPA 13 conventions, domestic and mechanical systems to plumbing code), verifying a repair held before backfill or re-energising, and settling a dispute about whether a system is sound. Engineers, inspectors, and insurers frequently require a documented hydrostatic test as the acceptance gate — which is why the report matters as much as the test.

They answer different questions and work together. Hydrostatic testing tells you whether a system holds and, if it doesn't, how much it's losing — but not where. Leak detection (acoustic, tracer gas, thermal) then pinpoints the failure so it can be repaired. The professional sequence is often test → if it fails, detect and pinpoint → repair → re-test to confirm. We provide both halves, so a failed test moves straight to a located leak instead of a guess.

Buried water mains and service lines, fire suppression and standpipe systems, domestic water risers and distribution, hydronic heating and chilled-water loops, glycol and process piping, backflow and booster assemblies, and tanks and vessels. Each is tested to the pressure and hold time its governing code or specification requires, and isolated properly so the result reflects the section under test, not the whole system.

The hold period is set by code or spec — fire lines are commonly held at 200 psi for two hours; water mains and other systems have their own durations — so a test runs from a couple of hours to most of a day including setup, filling, isolation, the hold, and depressurisation. We schedule around your commissioning or operations window and document the full pressure record, not just the final reading.

A documented test record: the system tested, test pressure, hold period, pressure readings over time, pass/fail against the governing criterion, and any loss measured — formatted for inspectors, engineers, insurers, and commissioning files. If the test fails, that record becomes the starting point for our leak detection crews to pinpoint the failure. See our leak detection reports service for the documentation framework.