Hydrostatic testing is one of most commonly carried out procedures for checking the performance of pressure in vessels. The testing is used especially used to verify pressure vessels like cylinders, boilers and tubes that may have leakages or other flaws that need identifying.
The process is significant for safety of pressure vessels and their strength and stability when operating under pressure. This technique is normally utilised under the industry requirements or upon customers demand or specification. Usually, there are more leaks in low pressure techniques that you can help detect through hydrostatic testing. It is also used to help check proof pressure and burst pressures.
Hydrostatic testing will help you;
• Detect definite leak locations
• Verify a pressure design is suitable for an application or not
The actual procedure of hydrostatic testing is relatively simple to understand. Incompressible fluids like oil and water are used for this test, where the vessel to be examined is filled with the fluid. The test will confirm if there is any leak, manufacturing flaw or enduring change in the shape of the vessel. In order to make leaks easier to detect, the addition of red or fluorescent dye in liquid contained in the vessel is used.
As a safety factor, pressure applied to the vessel for the test should be higher than its expected operating pressure, ensuring that the vessel can operate during times of overcapacity. Normally, a vessel should be tested at a safety margin of 150% of its operating pressure, depending on regulations. For instance, if a vessel is rated to 2015psi (139 bar), then it should be tested at about 3360psi (232 bar). Water, combined with a dye is the most commonly used fluid for this, as it is more compressible than any other liquid. The vessel which is to be tested is placed in another sealed vessel and filled with water.
Generally, a water jacket test is used for testing of small pressure vessels, which must be tested visually and inspected internally, before being placed in water, filled with container and monitoring water levels. The vessel is then pressurized for around 30 seconds and following the de-pressurizing, water level is check which would be raised is vessel distorts due to pressure change and unable to return to original volume.
When you get your vessels tested professionally, you will know that appropriate safety checks during and after the testing processes have been completed, ensuring that your vessel has been given an accurate review before taking further measures.