Application standards for pressure pipeline components in China

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Application standards for pressure pipeline components in China – I. SH petrochemical, HG chemical, JB machinery, and GB** standards. There are numerous application standards for pressure pipeline components in China; however, none of them is comprehensive. Taking pipe flange standards as an example, common standards include GB** standards, JB mechanical industry standards, SH petrochemical industry standards, and HG chemical industry standards, among others. Each of these standards has its own temperature-pressure gauge, seal surface dimensions, and pipe connection dimensions; they have poor interchangeability with one another, and some cannot even be used together. To make effective use of these standards, this article introduces the currently widely used standard system for pressure pipelines in China. II. Application Standard System for the Petrochemical Industry (SH) 1. The standards for pipe size series (SH3405) belong essentially to the \"large outer diameter series\". SH3405 is equivalent to the ISO4200 standard; therefore, when DN ≤ 1100 mm, it can be used in conjunction with the ANSI B36.1/36.19 standards. SH3405 diameter range and wall thickness classification: Serial number, steel pipe category, nominal diameter range, wall thickness classification. (1) Austenitic stainless steel seamless pipes: 10~400Sch5s, Sch10s, Sch20s, Sch40s, Sch80s. (2) Carbon steel and alloy steel seamless pipes: 10~600Sch20, Sch30, Sch40, Sch60, Sch80, Sch100, Sch120, Sch140, Sch160, XXS. (3) Austenitic stainless steel welded steel pipes: 80~1000, 2.0~12 mm. (4) Welded steel pipes of carbon steel and alloy steel: 150~2000, 4.0~18 mm. 2. Flange standards (SH3406): These fall under the category of “American-style flanges”. (1) Nominal pressures: There are 8 grades: PN1.0, PN2.0 (CL150), PN5.0 (CL300), PN6.8 (CL400), PN10.0 (CL600), PN15.0 (CL900), PN25.0 (CL1500), and PN42.0 (CL2500). (2) Nominal diameter: DN15~DN1500mm. (3) Flange sealing surface: When DN≤600, there are 5 types: boss surface, male-and-female surface, full flat surface, tenon-and-socket surface, and ring groove surface. (4) When DN≥650, there is 1 type of boss surface. (5) Flange types: When DN≤600, there are five types: butt welding, butt fusion welding, socket welding, threaded connection, and loose flange. (6) For butt welding when DN≥650, there is 1 type. 3. SH3406 essentially adopts the ANSI B16.5 and API 605 standards. SH3406 is highly interchangeable with ANSI B16.5/API605 in terms of structural dimensions and seal face types, and it can be used in conjunction with pipe fittings that comply with ANSI, API, MSS, and other standards. However, since SH3406 adopts China’s material standards rather than American material standards (ASTM), there is a slight difference between the temperature-pressure charts of the two. Therefore, when considering their interchangeability, it is necessary to pay attention to and verify the allowable values for temperature and pressure corresponding to each. 4. Commonly used standards within the application standard system for the petrochemical industry: SH3401 – Asbestos rubber sheet gaskets for pipe flanges; SH3402 – PTFE-coated gaskets for pipe flanges; SH3403 – Metal ring gaskets for pipe flanges; SH3404 – Fasteners for pipe flanges; SH3405 – Dimension series of steel pipes used in petrochemical enterprises; SH3406 – Steel pipe flanges for petrochemical applications; SH3407 – Spiral-wound gaskets for pipe flanges; SH3408 – Seamless steel butt-weld fittings; SH3409 – Butt-weld fittings made of steel plates; SH3410 – Socket-weld fittings made of forged steel. The application standard system for the petrochemical industry constitutes a relatively complete set of standards. Since it effectively adopts ANSI standards, it represents the direction of advancement and development. Also, its flange (SH3406) can be used in conjunction with API-standard valves. In recent years, its application has proven that this application standard system is a scientific, advanced, and highly operable standard system. III. Application standard system for the chemical industry (HG)
1. Standard for pipe size series (HG20553): Series A belongs to the “large outer diameter series”; Series B belongs to the “small outer diameter series”. 2. The flange standards include both European-style and American-style flanges. (1) European-style flanges (HG20592～HG20605): ① Pressure grades: 10 grades including PN0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, 16.0, 25.0. ② Nominal diameter: DN10~DN2000mm. ③ Flange types: 10 types in total, including plate type face welding, necked face welding, necked butt welding, integral type, socket welding, threaded type, loose-ring butt welding, loose-ring face welding, flange cover, and lined flange. ④ Sealing surface types: convex surface, male-female surface, tenon-mortise surface, ring connection surface, and fully flat surface – a total of 5 types. ⑤ It can be used in conjunction with JB valves. (2) American flange standards (HG20615-HG20626) ① Nominal pressures: PN2.0, PN5.0, PN11.0, PN15.0, PN26.0, and PN42.0 – a total of 6 pressure levels. ② Nominal diameter range: DN15~1500. ③ Flange types: there are 6 types, including socket weld with neck, butt weld with neck, integral flange, socket and spigot weld, threaded, and loose sleeve. ④ There are 5 types of sealing surface configurations: convex surface, concave-convex surface, tenon-mortise surface, ring connection surface, and fully flat surface. 4. The standard system for the application of pressure pipelines in the chemical industry is also a relatively complete one; it has been tested through years of practical use, boasting mature experience in its application. Due to its availability in both the \"large outer diameter series\" and the \"small outer diameter series\", as well as in the \"European flange\" and \"American flange\" categories, it has a wide range of applications. It can be used in conjunction with foreign standards such as ANSI, DIN, and ISO, as well as with domestic standards such as GB, SH, and JB. 5. Common standards in the application standard system for the chemical industry: HG20537.1 – Specifications for welded austenitic stainless steel pipes; HG20553 – Series of dimensions for seamless and welded pipes used in chemical piping; HG/T21634 – Forged steel socket-welded fittings; HG/T21635 – Butt-welded fittings made of carbon steel and low-alloy steel; HG/T21631 – Welded steel butt-welded fittings; HG/T21632 – Forged steel socket-welded, threaded, and butt-welded pipe fittings; HG/T21637 – Filters for chemical pipelines; HG/T21577 – Quick-special connectors; HG20592–20605 – Steel pipe flanges (European system); HG20615–20626 – Steel pipe flanges (American system); HG20606–20612 – Gaskets for steel pipe flanges (European system); HG20627–20633 – Gaskets for steel pipe flanges (American system); HG20613 – Fasteners for steel pipe flanges (European system); HG20634 – Fasteners for steel pipe flanges (American system). IV. Application standard system for the machinery industry (JB): 1. Pipe dimensions belong to the “small outer diameter series”. 2. Flange standard: European-style flanges. ① Pressure ratings: There are 10 pressure ratings, namely PN0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, 16.0, and 20.0. ② Nominal diameter: DN15~DN1600mm. ③ Flange types: 7 types in total, namely integral, plate-type butt weld, butt weld, loose flanged ring-plate type butt weld, loose flanged ring-plate type butt weld, loose flanged flared plate type, and flange covers. ④ Sealing surface types: flat, convex, concavo-convex, tenon-and-socket, and ring-connected – 5 types in total. 3. JB does not have corresponding standard series for pipe sizes or fitting standards; its system is quite incomplete and requires support from the GB system. 4. The JB flange standard includes materials of different grades in the same temperature-pressure table, thereby losing its scientific validity. 5. The JB valve standards specify the applicable series based on a limited number of models (as reflected in various product compilations). This not only restricts their scope of use but also diminishes their flexibility. Judging from the application of many production units, the performance of JB valves is also unsatisfactory ； JB valves cannot be used in conjunction with ANSI standards, which makes it difficult to integrate them with the global market. 6. Commonly used standards in the application standard system for the machinery industry include: JB/T74 Technical requirements for pipe flanges; JB/T75 Types of pipe flanges; JB/T79.1–79.4 Integral cast steel pipe flanges; JB/T81 Plate-type butt-welded steel pipe flanges; JB/T82.1–82.4 Butt-welded steel pipe flanges; JB/T830.25, 0.6, 1.0, 1.6, 2.5 MPa flat-welded loose-flange type steel pipe flanges; JB/T844.0, 6.3, 10.0 MPa male-female surface butt-welded ring-plate type loose-flange steel pipe flanges; JB/T850.0.25, 0.6 MPa flanged loose-flange type steel pipe flanges; JB/T86.1–86.2 Steel pipe flange covers; JB/4700–4703 Flanges for pressure vessels; JB/T87–90 Gaskets for pipe flanges; JB4704–4706 Gaskets for pressure vessels. V. **Application Standard System (GB)** 1. The standard GB17395 regarding pipe dimension series falls under the “large outer diameter series”. 2. Flange standards: (GB/T9112-2000) include European-style flanges and American-style flanges. (1) Takeover is divided into Series I and Series II. (2) Series I is the “large outer diameter series” to enable compatibility with SH standards and others. (3) Series II is the “small outer diameter series” in order to be compatible with standards such as JB. 3. European flanges: Divided into Series I and Series II. (1) There are 9 pressure classes with nominal pressures of PN0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, and 16.0 MPa. (2) Nominal diameter DN10～2000mm. (3) Flange types: 9 types in total, including integral, necked threaded, butt-welded, necked flat-welded, plate flat-welded, flat-welded ring plate loose fit, butt-welded ring plate loose fit, flanged ring plate loose fit, and flange cover. (4) Seal surface type: flat, convex, concave-convex, and tenon-mortise – 4 types in total. 4. American flange: Series I (large outer diameter) (1) There are six grades of nominal pressure: PN2.0, 5.0, 11.0, 15.0, 26.0, and 42.0 MPa. (2) Nominal diameter DN10～600mm. (3) Flange types: 7 types in total, including integral, necked with threads, butt-welded, necked with flat welding, necked with socket welding, butt-welded ring with necked loose sleeve, and flange cover. (4) Seal surface types: flat, convex, concave-convex, tenon-mortise, and ring-connected – 5 types in total. 5. It essentially covers the “European system” standards stipulated in both JB and HG standards, thus creating the conditions for replacing these two standards. 6. For both “European flanges” and “American flanges”, the temperature-pressure rating values are determined by comparing the properties of Chinese materials with those of European and American materials; subsequently, the pressure-temperature parameters of the corresponding materials specified in ISO7005-1 are selected. 7. The **standard system for pressure pipelines is also a relatively complete standard system. Its pipe fitting standards are divided into two series: A and B. The A series is the “large outer diameter series”, designed to be compatible with standards such as the SH standard ； Series B is the “small outer diameter series” in order to be compatible with standards such as JB. 8. Common standards in China’s application standard system for pipes: GB, GB12459 – Welded seamless steel pipe fittings; GB/T13401 – Welded pipe fittings made of steel plates; GB/T14626 – Threaded pipe fittings made of forged steel; GB/T14382 – Three-way filters for pipelines; GB/T14383 – Socket-welded pipe fittings made of forged steel; GB/T9112–9124 – Steel pipe flanges; GB4622.1–3 – Spiral gaskets for pipe flanges; GB9126.1–4 – Asbestos rubber gaskets for pipe flanges; GB9128.1–2 – Metal ring gaskets for pipe flanges; GB/T13404 – PTFE-coated gaskets for pipe flanges; GB/T15601 – Metal-clad gaskets for pipe flanges; GB30 – Hexagon bolts; GB52 – Hexagon nuts; GB56 – Thick hexagon nuts; GB901 – Equal-length double-ended studs, Grade B; GB6170 – Hexagon nuts, Type I, Grades A and B; GB6171 – Hexagon nuts, Type I, fine thread, Grades A and B; GB6175 – Hexagon nuts, Type II, Grades A and B; GB6176 – Hexagon nuts, Type III, fine thread, Grades A and B. 6. Application standard system for pressure pipelines: There are many available application standard systems for pressure pipelines, and some of these systems cannot be used together. While some can be used in combination, there are still certain issues that need to be taken into account. 2. One device, or several devices constructed simultaneously, should preferably adopt the same application standard system, thereby avoiding errors that may arise from compatibility issues between different standard systems. 3. In engineering, it is common to encounter situations where two or more sets of application standard systems are used simultaneously on a single device, or where the application standards of one set of standards are incomplete and thus require support from the standards of other systems. This requires material engineers to not only be familiar with the relevant standard systems but also understand the compatibility issues between the standards in these systems. 4. Pay attention to checking the temperature-pressure values for each standard.