Automatic High Pressure Steel Pipe Hydrostatic Testing Machine

It verifies the leak-tightness and structural integrity of welded or seamless steel pipes by filling them with water and applying internal pressure higher than the service rating. The test detects micro-cracks, pinholes, and weld defects that could cause failure in service. It is mandatory for International standard, and other pipeline standards. The machine automatically pressurizes, holds for a set dwell time (usually 5-15 seconds), monitors pressure drop, and records results.

Two main sealing methods are used: end-face (axial) sealing and radial (OD) sealing. End-face sealing uses a rubber seal pressed against the pipe's bevelled end, suitable for small to medium diameters. Radial sealing uses expandable rubber sleeves or O-rings gripping the outer surface, often applied to large-diameter pipes. Both systems are hydraulically actuated to achieve clamping forces up to several hundred tons.

The test pressure is usually 1.5 times the specified minimum yield strength (e.g., for X60, about 60-70 MPa), but may vary per customer specification. Hold time ranges from 5 to 30 seconds depending on pipe diameter and wall thickness. During the hold phase, pressure sensors monitor any drop - a permissible loss is normally within 2% of set pressure; beyond that indicates leakage or expansion. Modern machines have automatic rejection systems that mark bad pipes.