Pipelines and other similar units have to be occasionally tested to see if there are existing or possible leaks and if their performance is still adequate. Hydro testing is usually required by authorities after different repairs, but it has to be performed in regular intervals just to check if everything is working properly. Similar testing is used for pressure vessels and other pressure units.
This testing is performed when the whole system is shut down, and cannot be done when it is running. The test is nondestructive testing method and it might be necessary to be performed before different licenses for normal operating can be issued. The whole unit has to be checked for leaks and other problems that could be the cause of failure.
Pipelines are checked by removing whatever they suppose to carry in their normal operational state. This might be gas, oil or something else. After that, the pipes need to be cleaned, and after that, filled with water, until there is no air left in them. When the pipes are filled, the pressure should be applied. This pressure exceeds the normal pressure these pipes are designed for.
In this particular process, the pressure used for testing should be approximately 50 percent higher than the pressure this pipeline is designed for. This pressure should remain for some time, until the official persons visually check the unit for cracks or leakages. In some cases, fluorescent dyes may also be used, to ease the procedure and to make it possible to find the origin of leaks.
Once everything is checked, the water leaves the pipes. It's important to vent the pipes and that they are perfectly dry before they can be filled with oil, gas or whatever they suppose to carry. The water may cause corrosion, and needs to be removed entirely. Different liquids may have different properties.
Small vessels, cylinders and similar equipment and units are tested using different methods. There are three main types that are used, and some are more applicable for particular purposes. Direct expansion method is normally used for testing the pressure vessels. In this process, the vessel should be filled with water, and then the pressure is applied, for designated amount of time. Resulting expelled water is measured for testing results.
The second method is similar, but the vessel filled with water is first loaded into a sealed chamber, so called test jacked. This is why this method is called water jacket method. While in the sealed chamber, the vessel is pressurized. The applied pressure forces some amount of water out from the chamber, and the water that is expelled is measured to find out total expansion.
After the pressure is removed, tested vessel should slowly shrink back to its original size. Sometimes it does, and sometimes it doesn't. If it does, everything is in order, but if it doesn't, depending of the shrink-back percentage, it might require a service. When it's not important to have these numbers, it's easier to use so called pressure method. It will be enough to check the unit for leaks or other issues that can cause failures, for example, wall thinning.
This testing is performed when the whole system is shut down, and cannot be done when it is running. The test is nondestructive testing method and it might be necessary to be performed before different licenses for normal operating can be issued. The whole unit has to be checked for leaks and other problems that could be the cause of failure.
Pipelines are checked by removing whatever they suppose to carry in their normal operational state. This might be gas, oil or something else. After that, the pipes need to be cleaned, and after that, filled with water, until there is no air left in them. When the pipes are filled, the pressure should be applied. This pressure exceeds the normal pressure these pipes are designed for.
In this particular process, the pressure used for testing should be approximately 50 percent higher than the pressure this pipeline is designed for. This pressure should remain for some time, until the official persons visually check the unit for cracks or leakages. In some cases, fluorescent dyes may also be used, to ease the procedure and to make it possible to find the origin of leaks.
Once everything is checked, the water leaves the pipes. It's important to vent the pipes and that they are perfectly dry before they can be filled with oil, gas or whatever they suppose to carry. The water may cause corrosion, and needs to be removed entirely. Different liquids may have different properties.
Small vessels, cylinders and similar equipment and units are tested using different methods. There are three main types that are used, and some are more applicable for particular purposes. Direct expansion method is normally used for testing the pressure vessels. In this process, the vessel should be filled with water, and then the pressure is applied, for designated amount of time. Resulting expelled water is measured for testing results.
The second method is similar, but the vessel filled with water is first loaded into a sealed chamber, so called test jacked. This is why this method is called water jacket method. While in the sealed chamber, the vessel is pressurized. The applied pressure forces some amount of water out from the chamber, and the water that is expelled is measured to find out total expansion.
After the pressure is removed, tested vessel should slowly shrink back to its original size. Sometimes it does, and sometimes it doesn't. If it does, everything is in order, but if it doesn't, depending of the shrink-back percentage, it might require a service. When it's not important to have these numbers, it's easier to use so called pressure method. It will be enough to check the unit for leaks or other issues that can cause failures, for example, wall thinning.
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