The boiler in a modern Thermal Power Plant produces steam at very high pressures and temperatures. One of the most important yet simple test that ensures the integrity of the boiler is the ‘Hydrostatic Test’.
A string of catastrophic failures marked the starting era of the steam engine. The boiler explosion in the Grover Shoe Factory in Brockton, Massachusetts on March 10, 1905 triggered the implementation of the boiler safety rules. Today, stringent regulations control the boiler design, materials, manufacture and operation. These are mandatory as per law all over the world.
The test consists of filling the Boiler with water and pressurizing the water to at least one and half times the maximum operating pressure for a short time. Every part is subject to more than the maximum stress it will normally encounter. This is an endurance test; any weak link fails during the test.