China’s pipeline standard system-There are many application standards for pressure pipeline components in China, but they are not complete. Take the pipe flange standard as an example, the commonly used standards include GB national standard, JB machinery industry standard, SH petrochemical industry standard and Hg chemical industry standard. Each of these standards has its own temperature pressure gauge, sealing surface size and nozzle size. The interchangeability between them is poor, and some can not even be used together. In order to apply these standards well, this paper introduces the commonly used Chinese pressure pipeline application standard system.
Application standard system of petrochemical industry
◆ pipe size series standard (sh3405) basically belongs to “large outer diameter series”
Sh3405 equivalently adopts iso4200 standard, so when DN ≤ 1100mm, it can be used with ANSI b36.l/36.19 standard.
Sh3405 diameter range and wall thickness classification:
No. steel pipe category nominal diameter range wall thickness classification
1) austenitic stainless steel seamless steel pipe 10 ~ 400 (sch5s, sch10s, sch20s, sch40s, sch80s)
(2) carbon steel and alloy steel seamless steel pipe 10 ~ 600 sch20, sch30, sch40, sch60, sch80, sch100, sch120, sch140, sch160, XXS
(3) austenitic stainless steel welded steel pipe 80 ~ 1000 (2.0 ~ 12mm)
(4) carbon steel and alloy steel welded steel pipe 150 ~ 2000 (4.0 ~ 18mm)
◆ flange standard (sh3406): it belongs to “American flange”
Nominal pressure: PN1.0, pn2.0 (cl150), pn5.0 (cl300), pn6.8 (cl400), pn10.0 (cl600),
Pn15.0 (cl900), pn25.0 (cl1500) and pn42.0 (cl2500)
Nominal diameter: DN15 ~ dn1500mm
Flange sealing surface: when DN ≤ 600, there are 5 kinds of convex surface, concave convex surface, full plane, tenon groove surface and ring groove surface
When DN ≥ 650, one convex table
Flange type: when DN ≤ 600, there are 5 types of flat welding, butt welding, socket welding, threaded connection and loose sleeve
China’s pipeline standard system
1 type of butt welding when DN ≥ 650
※ sh3406 is equivalent to ANSI B16.5 and API 605 standards. Sh3406 has good interchangeability with ANSI b16.5/api605 in structure size and sealing surface type. It can be used with ANSI, API, MSS and other standard pipe components. However, since sh3406 adopts Chinese material standard instead of American material standard (ASTM), there is a slight deviation between the temperature and pressure gauges of the two. Therefore, when considering the interchangeability of the two, attention should be paid to and the corresponding allowable values of temperature and pressure should be checked.
◆ common standards in the petrochemical industry application standard system
Asbestos rubber plate gasket for sh3401 pipe flange
PTFE coated gasket for sh3402 pipe flange
Sh3403 metal ring gasket for pipe flange
Fasteners for sh3404 pipe flange
Sh3405 steel pipe size series for petrochemical enterprises
Sh3406 petrochemical steel pipe flange
Sh3407 spiral wound gasket for pipe flange
Sh3408 steel butt welded seamless pipe fittings
Sh3409 steel plate butt welded pipe fittings
Sh3410 forged steel socket welded pipe fittings
The application standard system of petrochemical industry belongs to a relatively complete application standard system. Because it is equivalent to ANSI standard, it represents the advanced and development direction. And because its flange (sh3406) can be matched with API standard valves. The application in recent years has proved that this set of application standard system is a scientific, advanced and operable standard system.
Application standard system of chemical industry
◆ pipe size series standard (hg20553) series a: it belongs to “large outer diameter series”
Series B: belongs to “small outer diameter series”
◆ flange standard includes European flange and American flange
European flange (hg20592 ～ hg20605)
Pressure rating: PN 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, 16.0, 25.0, etc
Nominal diameter: dn10 ~ dn2000mm
Flange type: plate type flat welding, neck type flat welding, neck type butt welding, integral type, socket welding, thread, loose sleeve of butt welding ring, loose sleeve of flat welding ring, flange cover, lining flange, etc
Sealing surface type: convex surface, concave convex surface, tenon groove surface, ring connection surface, full plane, etc.
It can be used with JB valve
American flange standard (hg20615-hg20626)
Nominal pressure: pn2.0, pn5.0, pn11.0, pn15.0, pn26.0 and pn42.0
Nominal diameter: DN15 ~ 1500
Flange type: 6 types, including neck flat welding, neck butt welding, integral flange, socket welding, thread, loose sleeve, etc,
There are 5 types of sealing surface: convex surface, concave and convex surface, tenon and groove surface, ring connecting surface and full plane
※ the pressure pipeline application standard system in the chemical industry is also a relatively complete standard system, which has experienced several years of production practice and has mature use experience. Because it has two series of “large outer diameter series” and “small outer diameter series”, “European flange” and “American flange”, it has a wide range of applications. It can be used in combination with foreign ANSI, DIN, ISO and other standards, as well as domestic GB, SH, JB and other standards.
◆ common standards in the chemical industry application standard system
Hg 20537.1 specification for selection of austenitic stainless steel welded steel pipe
Hg 20553 seamless and welded steel pipe size selection series for chemical piping
Hg / T 21634 forged steel socket welding pipe fittings
Hg / T 21635 carbon steel and low alloy steel butt welded pipe fittings
Hg / T 21631 steel seam butt welded pipe fittings
Hg / T 21632 forged steel socket welded, threaded and butt welded pipe stand
Hg / T 21637 chemical pipeline filter
Hg / T 21577 quick special connector
Hg 20592 ~ 20605 steel pipe flange (European system)
Hg 20615 ~ 20626 steel pipe flange (American system)
Hg 20606 ~ 20612 gasket for steel pipe flange (European system)
Hg 20627 ~ 20633 gasket for steel pipe flange (American system)
Hg 20613 steel pipe flange fastener (European system)
Hg 20634 steel pipe flange fastener (American system)
Application standard system of machinery industry
◆ pipe size belongs to “small outer diameter series”
◆ flange standard: European flange
Pressure grade: PN 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, 16.0, 20.0 and other 10 pressure grades
Nominal diameter: DN15 ~ DN1600mm
Flange type: integral, plate flat welding, butt welding, flat welding ring plate loose sleeve, butt welding ring plate loose sleeve, flanging plate loose sleeve and flange cover
Sealing surface type: plane, convex, concave and convex, tenon and groove surface and ring connection surface.
※ JB does not have corresponding pipe size series standards and pipe fitting standards, and the system is very imperfect and needs the support of GB system;
JB flange standard lists different grades of materials in the same temperature pressure gauge, thus losing its scientificity;
JB valve standard gives the selection series with limited models (reflected in the product assembly), which not only limits its use range, but also loses its flexibility. From the application of many production units, the performance of JB valves is not satisfactory; JB valves can not be used in combination with ANSI, which is not convenient to connect with the world;
◆ common standards in the application standard system of the machinery industry include:
JB / T74 technical conditions for pipeline flanges
JB / T75 pipeline flange type
JB / t79.1 ~ 79.4 integrally cast steel pipe flange
JB / T81 plate flat welded steel pipe flange
JB / t82.1 ~ 82.4 butt welded steel pipe flanges
JB / t83 0.25, 0.6, 1.0, 1.6, 2.5MPa flat welding ring loose steel pipe flange
JB / T84 4.0, 6.3, 10.0MPa concave convex face welded ring plate loose steel pipe flange
JB / T85 0.25, 0.6MPa flanged loose sleeve steel pipe flange
JB / t86.1 ~ 86.2 steel pipe flange cover,
JB / 4700 ～ 4703 flanges for pressure vessels
JB / T87 ~ 90 gasket for pipeline flange
Jb4704 ~ 4706 gasket for pressure vessel
National applied standard system
◆ pipe size series standard gb17395 belongs to “large outer diameter series”
◆ flange standard: (GB / T 9112-2000) including European flange and American flange
Nozzle is divided into series I and Series II
Series I is “large outer diameter series” in order to match sh standard;
Series II is “small outer diameter series” in order to match JB standard.
European flange: divided into series I and II,
Nominal pressure: PN 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, 16.0mpa, 9 grades
Nominal diameter: dn10 ～ 2000mm
Flange type: integral, with neck thread, butt welding, with neck flat welding, plate flat welding, flat welding ring plate loose sleeve, butt welding ring plate loose sleeve, flanging ring plate loose sleeve and flange cover
Sealing surface type: plane, convex surface, concave convex surface and tenon groove surface.
American flange: Series I (large outer diameter)
Nominal pressure: PN 2.0, 5.0, 11.0, 15.0, 26.0, 42.0mpa (6 grades)
Nominal diameter: dn10 ～ 600mm
Flange type: integral, with neck thread, butt welding, with neck flat welding, with neck socket welding, butt welding ring with neck loose sleeve and flange cover
Sealing surface type: plane, convex surface, concave convex surface, tenon groove surface and ring connection surface.
※ it can basically include “European system” standards covering JB standards and Hg standards, creating conditions for replacing these two standards;
※ for “European flange” and “American flange”, the temperature pressure rating value is determined by comparing the performance of Chinese materials with European materials and American materials, and selecting the pressure temperature parameters of corresponding materials specified in iso7005-1.
※ the national standard system of pressure pipeline is also a relatively complete standard system. Its pipe fitting standards are divided into two series: A and B. among them, a series is “large outer diameter series” in order to match with SH standard; B series is “small outer diameter series” in order to match JB standard.
◆ common standards of China’s national application standard system
GB 12459 steel butt welded seamless pipe fittings
GB / T 13401 steel plate butt welded pipe fittings
GB / T 14626 forged steel threaded pipe fittings
GB / T 14382 tee filter for pipeline
GB / T 14383 forged steel socket welded pipe fittings
GB / T 9112 ~ 9124 steel pipe flanges
GB 4622.1 ~ 3 spiral wound gaskets for pipe flanges
GB 9126.1 ~ 4 asbestos rubber gaskets for pipe flanges
GB 9128.1 ~ 2 metallic ring gaskets for pipe flanges
GB / T 13404 polytetrafluoroethylene coated gaskets for pipe flanges
GB / T 15601 metal clad gaskets for pipe flanges
GB 30 hexagon bolt
GB 52 hex nuts
GB 56 hexagon thick nuts
GB 901 equal length double head studs grade B
GB 6170 type I hex nuts, Grade A and B
GB 6171 type I hexagon nuts, fine thread, Grade A and B
GB 6175 type II hexagon nuts grade A and B
GB 6176 dish type hexagon nuts, fine thread, Grade A and B
Pressure pipeline application standard system
- There are many available standard systems for pressure pipeline application, and some of the standard systems cannot be used together. Although some can be used together, there are still some problems that should be paid attention to.
- The same application standard system shall be adopted as much as possible for one device or several devices constructed at the same time, so as to avoid some errors caused by the coordination between different standard systems.
- In the project, it is often encountered that two or more sets of application standard systems are used on a device at the same time, or because the application standards of one set of standard systems are not perfect, the standards of other systems need to be supported. This requires the material engineer to know not only the relevant standard system, but also the standard coordination between various systems.
- Pay attention to check the temperature pressure value of each standard.