Standards of pipe fittings

Application standard system

At present, most pressure pipes and their components have been serialized and supported by corresponding application standards.

Therefore, the first thing to consider when designing pressure pipe materials is the selection of standard series of pressure pipes and their components.

Apply the standardization system. A collection of series standards used by each component in a piping system (road).

These standards should include pipe series standards, pipe fitting series standards, flange and connecting parts standards, valve standards, etc.

These standards are applied in a piping system through certain rules. They correspond to each other and cooperate with each other to determine the basic

parameters of the pipeline and its components. Among these standards, pipe standards and flange standards are the most representative, and they are the basis

for other application standards. The following mainly introduces the application standards, focusing on pipe standards and flange standards.

At present, there are many standard systems applied in various countries in the world. Different countries and different industries have different application

standards and standards.

Systems, some of which are very different from each other, cannot be used in conjunction with each other and are interchangeable, thus causing a lot of trouble to users.

Therefore, the first step in the design of pressure pipelines is to choose and apply a standard system as a unified regulation for design, so as to avoid errors

caused by the use of other standard systems that cannot be replaced by various related disciplines.

Application standards in various countries around the world are generally divided into two categories:

• Pipes----The outer diameter series of steel pipes are divided into international common series (large outer diameter series) and British pipes:
• commonly used series in China (small outer diameter series) （diameter series) metric pipe (or metric pipe)
• Flange:
  European flange and American flange
  Pressure level: PS 0.1 0.25 0.6 1.0 1.62.5 4.06.3 10.0 16.0 25.0 40.0 MPa
  European flange (DIN)
  Pressure level: PS 2.05.0 6.8 10.0 15.0 25.0 42.0 MPa
  American flange (ANSI)
  CL 150 300 400 600 900 1500 2500 PSI
  It can be seen from this that the above two series or two systems cannot be mixed, whether it is flanges or pipes.
• ANSI-American National Standards Organization
  ASTM-American Society of Testing Materials
• Method of expressing steel pipe wall thickness

              There are three ways to express the wall thickness of steel pipes: pipe number, steel pipe wall thickness size and pipe weight.
1) The pipe number “sch” represents the wall thickness. The pipe number is the ratio of the pipe design pressure to the allowable stress of the material

at the design temperature multiplied by 1000 and rounded.

That is: Sch=P/[σ]×1000
ANSI B36.10 wall thickness grades: Sch10, Sch20, Sch30, Sch40, Sch6o, Sch8o, Sch10o, Sch120, Sch140, Sch160 ten grades:
ANSI B36.19 wall thickness grades: Sch5s, Sch10s, Sch40s, Schsos four grades;
2) Expressed in terms of steel pipe wall thickness (adopted by some steel pipe standards in China, IS0, and Japan)
3) The pipe wall thickness is expressed by the weight of the pipe, which divides the pipe wall thickness into three types:
a.Standard weight tube, expressed as STD b. Thickened tube, represented by XS c. Extra thick pipe, represented by xxs. For pipes with DN≤250mn,

Sch40 is equivalent to STD, and for pipes with DN<200mm, Sch80 is equivalent to XS.

• Commonly used international standard systems

   With China's reform and opening up and joining the WT0. Various industries are increasingly connected with the international community in order to 
better integrate with international standards.
It requires personnel engaged in pressure pipeline design to have an understanding of the internationally common and advanced relevant standard systems. 
The following introduces several main application standard systems.
Application standard system in Germany and the former Soviet Union
a.Germany (DIN)
Pipe: Large outer diameter series
Pipe flange: European flange
Pressure level: PN 0.1, 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.4, 10.0, 16.0, 25.0, 32.0, 40.0
13 levels
Nominal diameter: DN6~4000mm
Flange sealing surface: 7 types: flat surface, convex table surface, concave and convex surface, tongue and groove, rubber ring connection surface, 
lens surface and diaphragm welding surface
Flange type: flat welded plate type, flat welded loose sleeve type, flanged loose sleeve type, butt welding flanged loose sleeve type, butt welding ring
 flanged loose sleeve type, butt welding ring flanged loose sleeve type,
There are 9 types of welded, threaded, integral and flange covers.

Seamless sodium tube
Dimensions and mass per unit length

Welded steel pipe dimensions and unit length mass

flange  A description

flange  Connection size

Steel flange: technical delivery conditions

Threaded steel pipe fittings

b. Former Soviet Union (rOCT)
Pipe: small outer diameter bar, outer diameter size is the same as China’s JB bar
Pipe flange: European flange
Pressure level: PS0.1, 0.25, 0.6, 1.0, 1.6. 2.5, 4.0, 6.4, 10.0, 16.0, 20.0 11 levels
Nominal diameter: DN6-3000mm
Flange sealing surface: full plane, boss surface, four-convex surface, tongue and groove surface for PTFE, lens surface and oval ring pressing surface 7
kind
Flange type: flat welding plate type, flat welding loose sleeve type, flanged loose sleeve type, butt welding type, threaded connection type, integral type 
and flange 7 types
*The German pipe flange standard DIN and the former Soviet Union pipe flange standard "OCT" can be used in pairs in the PN ≤ 16.0 level, 
but cannot be interchanged 
(because the nozzle size series are different). With the disintegration of the former Soviet Union, its application standard system " OCT is currently rarely used
 in international engineering.
c. American Application Standards System (ANSI)

The American national standard ANSI B16.5 "Steel Pipe Flanges and Flange Fittings" is a relatively complete and mature standard that is also internationally
 popular and universal. 
The pressure pipeline application standard system composed of this standard and other related ANSI, API, ASTM, and MSS is formed on the basis of a large number of 
experimental studies and has experienced decades of practical testing. Therefore, it can be regarded as a scientific and advanced standard, and Widely accepted by various countries.
Pipe: Large outer diameter series
(ANSI B36. 10 and ANSI B36. 19)
Nominal diameter range: (DN6^ DN2000) mm
Wall thickness expression method:
1) The pipe number “Sch” represents the wall thickness;
2) The thickness of the pipe wall is expressed by the weight of the pipe.

Pipe flange: American flange
Pressure level: CL 150 300 400 600 900 1500 2500 Psi 7 levels
Nominal diameter: DN15^600mm
Flange sealing surface: 4 types: convex surface (RF), concave and convex surface (MF), mortise and tenon surface (TG), metal ring connection surface
Flange types: 6 types: flat welding type, socket welding type, butt welding type, threaded connection type, loose sleeve type and flange cover

Commonly used standards in the American applied standards system ANSI include:

ANSI/ASME B36. 10

Seamless and welded steel pipes

ANSI/ASME B36. 19

Stainless steel seamless and welded steel pipes

ANSI/ASME B16.9

Factory made steel butt weld fittings

ANSI/ASME B16. 11

Socket welding and threaded forged pipe fittings

ANSI/ASME B16.28

 Steel butt welding small radius elbows and return elbows

ASME/ANSI B16.34

Valves with flanged, threaded and welded connections

ASME/ANSI B16.5

 Pipe flanges and flange fittings

ASME/ANSI B16. 36

Orifice plate flange

ASME/ANSI B16. 42

Ductile Iron Flanges and Flange Fittings

ASME/ANSI B16. 47

Large Diameter Steel Flange

Wrap-type, covered gaskets and ring-grooved metal gaskets for pipe flanges

Non-metallic flat gaskets for pipe flanges

ASME/ANSI B18.2.1

Square and Hex Head Bolts and Threads

ASME/ANSI B18.2.2

 Square and Hex Head Nuts

API std605

Large diameter flange, flange cover

API std526

flanged steel pressure relief valve Inspection and testing of API std598 valves

API std599

flanged and welded metal plug valves

API std600

 Steel gate valves with flange and butt weld connections

API std602

 small steel gate valve (compact gate valve)

API std603

150 pound corrosion resistant flange valve

API std608

metal ball valve with flange connection and butt welding connection

API std609

lug type and wafer type butterfly valve

API std6D

Pipeline valve specifications

MSS SP-44

 flat welding flange with neck

 d.Japanese Application Standard System (JIS)
Pipe: Large outer diameter series (JIS C3454, JIS G3458, JIS C 3459) are mostly the same as ANSI
Nominal diameter of seamless steel pipe: (DNG^DN650) mm
Method of expressing wall thickness: Pipe table number "Sch" indicates wall thickness
Carbon steel and alloy steel JIS G3454, JIS G3458: Sch10, Sch20, Sch30, Sch40, Sch6o, Sch80,
Sch100, Sch120, Sch140, Sch160 10 levels:
Stainless steel JIS G 3459: Sch5s, Sch10s~Sch20s, Sch40s, Sch80s, Sch120s, Sch160s
7 levels;
Nominal diameter of welded steel pipe: (DN350~DN2000) mm
Wall thickness expression method: Press directly to express the wall thickness numerical value.
Pipe flanges: (JIS B2201, JIS B2220, etc.) form their own system and are neither "American flanges" nor "European flanges"
Nominal diameter: (DNI0^DN1000) mm
Nominal pressure levels: 2K, 5K, 10K, IGR, 20K, 30K, 40K, 63K, 8 levels in total
Flange sealing surface: 5 types: smooth surface, large convex surface, small convex surface, four-convex surface, and tongue and groove surface
Flange types: 6 types: flat welding type, socket welding type, butt welding type, threaded press type, loose sleeve type and flange cover

 *The JIS application standard system cannot be used in conjunction with ANSI and DIN. In order to make up for this shortcoming, 
the Japan Petroleum Institute compiled a set of JPI standards, which are basically equivalent to the ANSI/API application standard system, so it can be 
interchanged with ANSI.

 *Commonly used standards in the Japanese Application Standard System JIS are:

JIS G3452

general purpose carbon sodium tube

JIS G3454

carbon steel pipe for pressure bearing

JIS G3455

carbon steel pipe for high temperature

JIS G3457

arc welded carbon steel pipe

JIS G3458

alloy steel pipe

JIS G3459

stainless steel pipe

JIS G3468

 arc welding large diameter stainless steel pipe

JIS B2201

defective material pipe flange pressure grade

JIS B2202

Pipe flange size

JIS B2210

Ferritic material pipe flange basic dimensions

JIS B2220

 steel pipe flange

JIS B2302

steel threaded connecting pipe fittings

JIS B2311

 Steel butt welding pipe fittings for general purposes

TIS B2312

Steel Butt Welding Pipe Fittings

JIS B2313

steel plate butt welding pipe fittings

JIS B2316

Socket welded pipe fittings

JIS B2401

O-ring

JIS B2404

Wound gasket for pipe valve flange

JIS B3453

Compressed Asbestos Gasket

e.International Organization for Standardization (ISO) application standards system

Pipe: basically a large outer diameter series (ISO4200)
*Standard Huai (ISO4200) series 1 basically uses ANSI dimensions. Only when DN>1100mm (no longer commonly used), the "small outer diameter series"
 dimensions are used.
Pipe flange: including both "American flange" and "European flange" series. (ISO7005-1) It represents the current application trend of world flange standards.

Nominal pressure level:
The first series: pS 1.0, 1.6~2.0, 5.0, 11.0, 15.0, 26.0, 42.0 8 levels:

The first series: PN 0.25, 0.6, 2.5, 4.0 8 levels:

The first series is the basic series, and the second series is the limited series.

In the two series: PN0.25, PNO.6, PN1.0, PNI.6, PN2.5, PN4.0, the six grades belong to "European flange", PN2.0, PN5.0, PN11.0 ( 600Psi), PN15.0, 
PN26.0 (1500Psi), PN42.0 are "American flanges":

The structural dimensions and sealing surface dimensions of the two are not interchangeable.

 Commonly used standards in the ISO application standard system are:

ISO6708 

pipe fittings nominal size definition

ISO7268 

Welded and Seamless Plain End Steel Pipe Dimensions and Unit Lengths

ISO1127

Stainless steel pipe Dimensional tolerances and mass per unit length

 f.British Applied Standards System (BS)

 Pipe: Large outer diameter series

BS1600 Its diameter range and wall thickness classification are the same as ANSI B36.10/B36.11;
BS3600 Basically, it adopts the ISO standard, and its diameter range and wall thickness classification are the same as ISO4200.
*Flange standard: includes both "American flange" and "European flange" series.
BS1560 Basically it adopts the ANSI standard, and its structural type and sealing surface type are the same as ANSI B16.5;
BS4504 is basically equivalent to the DIN standard, and its structural type and sealing surface type are the same as DIN2500.

 Commonly used standards in today’s BS include:

BS1600

Steel pipe dimensions for petroleum industry

BS3600

Size and mass per unit length of welded steel pipes and seamless steel pipes for pressure

BS3605.1

Welded and seamless stainless steel pipes for pressure purposes

BS1560

Pipe flange (American flange)

BS4504

Pipe flange (European flange)

BS1560 pipe flange

pipe flange (American flange)

BS4504 pipe flange

(European style flange)

BS1740.1

Forged steel pipe fittings

BS1965

butt welding pressure-bearing pipe fittings

BS1640

butt welding pipe fittings for petroleum industry

BS3799

Threaded and socket welded pipe fittings for petroleum industry