Is it necessary to use low-temperature container steel plate for the saddle of low-temperature horizontal containers as well?
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Pressure: 2.16; temperature: -48 degrees. The ambient temperature should be above -20 degrees at the lowest. The medium used is propylene, and it’s a horizontal container. The material used for the plates is 09MnNiDR. Currently, 09MnNiDR is also used for the gussets and reinforcement plates of the base frame. I don’t think this is necessary; 09MnNiDR can be used for the gussets, while Q345R would suffice for the reinforcement plates. The manufacturer’s response was that, in the case of low-temperature containers, 09MnNiDR is used for the base frame as well to prevent brittle fracture due to low temperatures. I seek advice from those who are more knowledgeable!
The manufacturer’s recommendation is reasonable; it is suggested to use low-temperature materials for the saddle as well. Moreover, some low-temperature equipment requires the installation of shims beneath it to separate it from the foundation, thereby reducing the impact of low temperatures on the foundation.
Are these things you mentioned included in that standard? Or where did I see it
The price difference isn’t that big. . . . . Use the same one; there’s no need to worry. . .
The standards are either not specified or are quite vague, so judgment based on experience is required. You are a cryogenic medium, with such low temperatures; of course, the saddle must be made of cryogenic materials. If connecting to a standard foundation, and if the equipment does not have shims, it is recommended to use some shims.
JB/T4712.1 specifies that when the design temperature of the saddle is less than or equal to -20°C, other suitable materials should be selected based on the actual design conditions, or additional low-temperature testing requirements should be imposed on materials such as the web
What’s said above makes sense, but it’s hard to say exactly what degree the seat flange can reach. Should low-temperature steel plates be used just as a precaution?
The original poster is right; it’s completely fine to use 09MnNiDR for the saddle pad, while Q345R can be used for the other components. The saddle is merely a component that is subject to stress, and its plasticity transition temperature is below -30°C.
You also said it’s hard to say what degree the actual saddle web can reach; I think it’s best to use low-temperature steel plates. If it can be determined that the service temperature of the web is above -20 degrees, then Q345R could be considered, along with corresponding low-temperature impact requirements
Personally, I agree with the 6th floor’s view; specific operating conditions should be taken into account, along with different inspection requirements
The -20 degrees you mentioned should be a requirement for the stressed components; the supports, on the other hand, should be non-stressed components. I just feel that way, I guess. . . This thing wastes low-temperature steel plates; there’s no need to use them. . . I still feel uneasy. . .