Construction and welding techniques for nitrogen pipelines under low temperature and high pressure conditions
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As stated in the title, the current process is involved in building an experimental platform; the pipelines operate under high-pressure conditions of 20 Mpa at -196°C, and the medium is complex, existing in liquid, vapor-liquid, and gas states； All pipelines are made of 304 stainless steel, in accordance with the standard GB/T 14976-2012 ； Experienced sailors, please share your construction experience and precautions. I would be very grateful if you could also share any welding techniques you have used in such projects!
-196 degrees, are you sure to use 304?
Yes, 304 material can withstand low temperatures of -196°C without any problem, right?
No problem,,, normal welding. .
TIG welding is used for the root pass, while MIG welding is used for the fill pass; that’s the welding method. The issue is the difficulty in controlling the process, so perhaps it would be better to create samples first. It would be best to have a reference for the manufacturing process
There is no issue with welding; we use this material for both air separation units and air compressors. When welding, it is necessary to control the interpass temperature and wire energy
Normal welding will suffice, but I haven’t done it in practice; I’ll refer to the answers from others
Bro, could you provide the control parameters for current, temperature, etc.?
The temperature should be below 150 degrees according to the standard specifications; we generally keep it around 100 degrees. If the current is φ3.2, a value of over 90 is sufficient