Questions about standards?

In a project, pipes can follow American standards, German standards, Japanese standards, or Chinese standards. Who is responsible for designing these standards? It can’t be that one valve follows American standards while the next one follows Chinese standards

Generally, a fitting has two standards: one is the dimensional standard, and the other is the material standard； Currently, in some places a combination of standards is used; for example, in some CNPC projects, standards such as ASME 36.10/16.9 are applied for dimensional specifications. However, the material requirement is that 20# domestic material must be used; these are some of the requirements for localization. Theoretically, size standards and material standards should form a cohesive system, but in practice many of them do not match; each case needs to be analyzed on its own

For such common materials, such as 304 and 316L, when standards were first established, reference was made to American standards; this is what is known as adopting foreign standards, meaning it’s the same type of material； The design standards must follow the size standards; otherwise, the deviation would be too significant

Thank you for the reply; what I described is “or”. But it should be possible if the connection standards and material standards differ in a project. For example, DIN11864 connection, 316L material. We can assume that what the customer needs is stainless steel 316L, which corresponds to 1.4404. In the design documents, it can also be simply written as ANSI 316L. That’s my understanding. Thank you again

Materials have corresponding standards; for example, 316L corresponds to the American standard for such materials. Moreover, these standards are related to the intended use of the material – in different applications and equipment, even though it is still called 316L, the corresponding standard number may vary. Such as valves made of 316L, rolled to ASTM A182 standards. So, to determine what material to use, one must first consider what type of standard product it is.

Could we talk more openly? Thank you

It’s not easy to explain the standard system clearly; let me share my understanding. 1. Taking ASME 316L as an example, ASME is definitely part of the American standard system; the specific standards for 316L within this system are: A312 Gr TP316L for pipes (seamless steel pipes) ； Plate A240 Gr 316L (for pressure vessels, welded steel pipes, fittings) ； Forged A182 Gr F316L (for flanges and small-diameter valves) ； Castings A351 Gr CF3M (used for valve bodies in large-diameter cast valves) ； Wait. —It corresponds to what was said on the 6th floor. 2. SS304 is actually a general term for 304; as mentioned in the previous point, one should look for the corresponding standard in the DIN or JIS standard systems and use it ； But it is not equivalent to the US standard. DIN belongs to German standards, while JIS is the Japanese standard system. 3. The American standard has two standards for outer diameter and wall thickness, namely A and B; this is a bit unclear in its description. For American standards (usually referring to the ASME/ASTM series), the outer diameter of the pipes belongs to the imperial pipe system (a single series); flanges come in two series, A and B, and the outer diameter of these flanges varies (they differ in size and weight, with series A being larger than series B) ； The flanges correspond to the domestic standards HG/T20623 and SH/T3406 (those corresponding to national standard flange standards starting with the digit 9 are not listed; I personally prefer to use industry standards). The last two questions cannot be answered – they are too complex: lol. The domestic standards (national standards, SH standards, HG standards) generally rely mainly on the American standards (ASME) and European standard systems (DIN/EN); in essence, whatever standards are used as references, those are the ones that are adopted.

The design is definitely made according to a standard.

It’s impossible to mix several standards together.

This post was last edited by greensnow on 2019-4-3 22:39. 1. For example, if a project uses the connection standard ASME 316L or DIN 316L, we consider it to be the American standard or the German standard; but what standard applies to the material? A: For ordinary materials, if the description is complete, it’s possible to determine the standard. For example, in the case of pipes, if they are made to American standards, the designation will be A312 TP316L; whereas for DIN standards, codes such as 1.4435 or X2CrNiMo1812 are used – though this correspondence may not always be accurate; it’s just an example. The same applies to pipe fittings, which are identified based on both the material and dimensions. The same is true for German standards; it’s still easy to distinguish between DIN and ASME. (ANSI, ASTM, and ASME are all American standards.) 2. If a project uses DIN or JIS connection standards along with SS304 material, what are the design standards then? Can American standards be adopted as the design criteria? A: Connection standards – I’m not quite sure what you mean. Are you referring to the standards for selecting pipes and accessories? As for design standards, I believe they can be applied in countries that use different standards from those for materials; it’s just that relevant certifications may be required in different cases. 3. The American standard has two types, A and B, for outer diameter and wall thickness standards; which one is the same as the Chinese standard? A: HG comes in two types, AB, while GB has two series, I and II, with different outer diameter and wall thickness standards that correspond to American and European standards respectively, namely ASME and DIN. Generally, American standards specify thick-walled versions, while European standards specify thin-walled versions. 4. Among all the standards (American, German, Japanese, Chinese standards, etc.), which ones are applicable universally? A: In principle, it cannot be completely replaced; it depends on the specific circumstances, and there is no one-to-one correspondence. Even though our HGs are based on US and European standards, there are actually slight differences in dimensions. I’m unable to give you a satisfactory answer to this question. 5. Are there any standards such as ASME BPE, 3A, SMS, and DIN that are applicable universally? A: There is little contact with the plumbing fittings, so it’s unclear. But the principle is similar to that in Question 4; what you call a universal standard hardly exists. The dimensions specified by the American standard are generally in imperial units, while those specified by the DIN standard are in metric units. Please ask other experts to analyze its differences on your behalf.