Why is such a bypass installed on LNG pipelines?
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As shown in the diagram, why is a bypass with such a small diameter installed on the straight pipe section? PS: The one behind the large ball valve is a pipe support
It seems the ball valve was installed in the wrong position originally. Is this bypass pipe used for pressure stabilization at both ends of the original large ball valve? Similar to a heat pump?
Is this the bypass for the check valve? The bypass of a check valve is generally used when backflow is required.
Look at those with short pipes welded on – is there a control valve in the middle that isn’t installed when applying pressure?
It seems that the installation position of the large valve has been adjusted, while that small branch pipe for pre-cooling bypass hasn’t been modified yet.
It seems that the installation position of the large valve has been adjusted, and that small branch pipe for pre-cooling bypass is located at both ends of the large valve
The small valve and the large valve should be connected in parallel; the small valve serves as a balance valve for warming the pipes, or rather, when the medium first starts to flow, the pressure difference across the large valve is high, making it difficult to open. It is necessary to first open the small valve to balance the pressure inside the pipeline; this makes it easier to open the large valve later, as well as reducing the impact on the pipeline
A pressure-boost bypass for the pipeline is used to prevent high flow rates that can occur due to large pressure differences before and after the main valve~~for safety reasons~~. Similar valves are also used on oxygen pipelines, for the same reason~~
I think what was said on the 7th floor makes sense – the large valve was moved to another location, and a short pipe was welded in its original place.
There are short pipes with joints in the middle; they are likely not used during pressure testing and will be installed after the testing is completed.