How to blow out the water inside after a pressure test
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I would like to ask the experts: how can I blow out the water inside after a pressure test in order to prevent rusting?
This can be run through with dry steam, and then all the vent valves and backflow valves should be opened to speed up the drying process. If high requirements are placed on the moisture remaining in the pipes, it is possible to consider using a water-free process material (such as alcohol) to remove all the water; this depends on the type of fluid that is used in the pipe design.
Each case should be analyzed on its own; it’s best to break down the issues in detail to facilitate discussion. Such as containers, suitable for repeated vacuuming, gas replacement for drying, and manual cleaning. The pipeline is suitable for dry gas purging and various types of cleaning processes.
Heat the nitrogen; vent all low points.
If possible, conduct a pressure test (make sure to use a welding joint coefficient of 1), so that there will be no issue with water remaining during the pressure test. For hydraulic testing, it is also possible to use other water-free liquids (I haven’t tried this). If only water can be used for the hydraulic test, then dry it with dry hot nitrogen; there is no other option. Note that if rust must truly be avoided, nitrogen purging should be carried out after drying to reduce the oxygen content inside the test tank. And seal all pipe openings, preserving it under positive pressure. Only in this way can rust be prevented
If it is a pressure vessel that has been pressurized with water, there must be some residual water inside. Once the equipment is installed and all pipelines are connected, steam purging can be carried out; it’s just not clear what the results will be
Under normal circumstances, drain the water used in the test, keep the container open for ventilation, and blow it out with compressed air – it will dry up quickly.
This post was last edited by Niuniu Hu on 2020-7-7 23:35. Teacher, we used to do things the way you told us to. But the effect isn’t very good!
Of course, it depends on the specific environmental conditions; if the container has good ventilation and the ambient air is dry, there is no problem.
Theoretically, there are various methods, but in practice it’s impossible to clean it completely. To achieve a dry and clean environment, an air compressor plus a drying filter is still necessary to generate air pressure.
The design of the container must ensure that process drainage outlets are provided at the highest and lowest points of its vertical/horizontal position; these outlets should be covered with plugs when not in use, so as to allow for the easy drainage of water. If there is still a large amount of water remaining after the water has been drained, it becomes difficult to dry the container.