Regarding the re-inspection of the inner cylinder material
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Dear colleagues: This is a stainless steel vacuum-insulated container for storing LNG, with a design pressure of 1.94 MPa and a design temperature of -196 degrees Celsius. The inner cylinder (shell) is made of seamless stainless steel tubes of type S30408, and the design and manufacturing standards are GB150 and GB/T18442. My questions are as follows: 1. Does the material used for the inner cylinder (stainless steel tubes S30408) need to be retested before welding? HG20581 requires testing of the mechanical properties of the material – should this standard be followed? 2. Since the design documents (blueprints) do not reference HG20581, does it mean that this standard does not need to be applied during manufacturing? Thank you. :)
This post was last edited by zhangjuhua on 2015-10-12 08:56. I’m not entirely sure, but it seems that if all the necessary documentation and proof materials are available, there’s no need for the manufacturer to carry out the tests again. For S30408, use at -196℃ is standard; it’s not intended for low-temperature conditions or as a low-temperature material. As for whether it’s necessary to conduct further tests on the mechanical properties of the material in accordance with HG20581 requirements, as well as whether those manufacturing procedures must be followed, I think the design doesn’t specify this; as long as the specified standards are met, it’s sufficient to refer to them rather than follow them strictly
According to the requirements in 150, re-inspection is not necessary (Section 5.1). By the way, what is the volume of your product? Is it manufactured directly using seamless steel pipes? Should I use Rp0.2 or Rp1.0?
This post was last edited by mofei521 on 2015-10-12 08:45. Volume is 80 L, use Rp0.2. Thank you.
It is necessary to follow the requirements of 20581!
Do anyone else have any suggestions, based on the standards? Thank you.:):):):)
That’s a gas cylinder; you should use a cylinder specification, right?
The requirements for HG 20581 are higher than those for 150; if the design does not specify it, there is no need to comply with them
If the material of the inner cylinder is from the same batch as that of the outer cylinder, only the outer cylinder needs to be inspected
It’s not a gas cylinder; it’s an LNG submersible pump pool.
If 20581 is not specified in the drawings, it is not necessary to follow it. Refer to Clause 5.1 of GB150.4-2011; if none of the requirements are met, no retesting is necessary.