Regarding the loading crane pipe issue!
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Hello, dear sea industry colleagues. Our company is engaged in the production and sales of LNG. Our plant is equipped with 6 loading nozzles, and nitrogen is supplied to the joints at those nozzles. What is the purpose of this nitrogen? How high should the pressure be adjusted to? Does it have to be opened before and during loading? Can it be turned off directly after loading? Do I still need to wait until the flexible hose warms up before turning it off? What are the consequences of turning it off right after loading? Thank you all! I’ll give everyone a score after you answer!
Yes, then what is the usual setting for this pressure? In our factory, it’s considered sufficient as long as there is airflow; is this approach reasonable?
It definitely isn’t suitable; it needs to be higher than the design pressure for loading purposes. If the nitrogen pressure in the loading arm isn’t reduced, it will be the same as the pressure in the plant’s nitrogen system
Nitrogen is introduced into the interlayer of the manifold fitting of the unloading crane pipe, with the aim of blowing out the air inside the manifold fitting. This prevents the manifold fitting from freezing due to the low temperature of the material in the pipeline during unloading, which could otherwise render it immobile.
1. When the loading arm is in its retracted position, the nitrogen inlet pressure for the rotary joint lubrication system should be 0.04~0.06 bar.g. 2. Two hours before loading, this pressure should be increased to 0.2~0.4 bar.g. 3. After the loading arm returns to normal temperature following use, the pressure should be reduced back to 0.04~0.06 bar.g
Mobile phones are not allowed in the factory area, and there are no photos of the seats. On our factory’s loading arm, there is a very small copper pressure relief valve right at the nitrogen main pipe; however, it has never been adjusted – regulation is done entirely through the manual ball valve located at the front. Operators often forget to turn it on, which can lead to the loading arm getting stuck or to leaks! Our Hebi is connected together at each joint.
So it only serves a lubricating purpose? I wonder if it also has a sealing function?
Thank you very much for providing the data support! Thank you