Most useful standards in mechanical industry are the ANSI-(American National Standard Institute) standards.Each  country has its own Codes and Standards. On global basis, American National Standards are the most widely used  and compliance with those requirements are accepted world over.In general, other than American Standards such  as British ,German,Japanese,Europian and various other standards depending upon the requirement and  availability are also used for design and selection of Piping Systems.

Not all American Standards are issued directly by American National Standards Institute. However in  process/power industry ,the Material Standards are covered under ASTM (American Society for Testing and  Materials) and Dimension Standards under ANSI (American National Standards Institute). Most of these Standards  are adapted by ASME (American Society for Mechanical Engineers).

Some of the commonly used Standards referred by Piping are :

The American Petroleum Institute (API) :
API 5L – Specification for Line Pipe
API 6D – Pipe Line Valves, End Closures, Connectors and Swivels
API 6F – Recommended Practice for Fire Test for valves
API 593 – Ductile Iron Plug Valves – Flanged Ends
API 598 – Valve Inspection and Test
API 600 – Steel Gate Valves
API 601 – Metallic Gaskets for Refinery Piping
API 602 – Compact Design Carbon Steel Gate Valves
API 604 – Ductile Iron Gate Valves – Flanged Ends
API 605 – Large Diameter Carbon Steel Flanges
API 607 – Fire Test for Soft Seated Ball Valves
API 609 – Butterfly Valves

API 1104 – Standard for Welding Pipeline and Facilities

The American Iron and Steel Institute (AISI) : 

These standards specify the material by its Chemical and Physical properties. When specific model of  manufacture of the element is not to be specified, then the material can be identified by ANSI Standards. The  most commonly used AISI specifications are :
AISI 410 – 13% Chromium Alloy Steel
AISI 304 – 18/8 Austenitic Stainless Steel
AISI 316 – 18/8/3 Austenitic Stainless Steel  
American Society for Mechanical Engineers (ASME) :
ASME B 31.1 – Power Piping
ASME B 31.2 – Fuel Gas Piping
ASME B 31.3 – Process Piping
ASME B 31.4 – Pipeline Transportation System for Liquid Hydrocarbon and other Liquids.
ASME B 31.5 – Refrigeration Piping
ASME B 31.8 – Gas Transmission and Distribution Piping System
ASME B 31.9 – Building Services Piping
ASME B 31.11 – Slurry Transportation Piping System
ASME B 31.G – Manual for determining the remaining strength of corroded piping – A supplement to ANSI B31 

Of the above, the most commonly used code is ASME B 31.3. Refineries and Chemical Plants are designed based on  the same. All Power Plants are designed as per ASME B31.1. 

Other major ANSI / ASME Standards refereed for the piping elements are :
ASME B 1.1 – Unified Inch Screw Threads
ASME B 1.20.1 – Pipe threads for general porposes
ASME B 16.1 – Cast Iron Pipe Flanges and Flanged Fittings
ASME B 16.3 – Malleable Iron Threaded Fittings
ASME B 16.4 – Cast Iron Threaded Fittings
ASME B 16.5 – Steel Pipe Flanges and Flanged Fittings
ASME B 16.9 – Steel Butt Welding Fittings
ASME B 16.10 – Face to Face and End to End dimensions of Valves
ASME B 16.11 – Forged Steel Socket Welding and Threaded fittings
ANSI B 16.20 – Metallic Gaskets for Pipe Flanges – ring joint, spiral wound
ASME B 16.21 – Non Metallic Gaskets for Pipe Flanges
ASME B 16.25 – Butt Welding Ends
ASME B 16.28 – Short Radius Elbows and Returns
ASME B 16.34 – Steel Valves, Flanged and butt welding ends
ASME B 16.42 – Ductile Iron Pipe Flanges and Flanged Fittings – Class 150# and 300#
ASME B 16.47 – Large Diameter Steel Flanges – NPS – 26″ to 60″
ASME B 18.2 1 and 2 – Square and Hexagonal head Bolts and Nuts (Inch and mm)
ASME B 36.10 – Welded and Seamless Wrought Steel Pipes

ASME B 36.19 – Welded and Seamless Austinitic Stainless Steel Pipe

American Society for Testing Materials (ASTM) : 
These consist of 16 sections on definitions and  classifications of materials of construction and Test methods. Most of the ASTM Standards are adapted by ASME  and are specified in ASME Section II. The Section II has four parts.

1.Part A – Ferrous Materials 
2.Part B – Non-Ferrous Materials 
3.Part C – Welding Materials 
4.Part D – Properties of Materials 

In Section II, the materials are listed in the index based on the available forms such as plates, castings,  tubes etc., and also on the numerical index.

The selection of ASTM Specification depends on the manufacturer, form of material, its mechanical strength and  corrosion properties. 

The specification number is given an Alphabetical prefix “A” for ferrous and “B” for non-ferrous  materials.

ASTM also specifies standard practice for numbering metal and alloys as Unified Numbering System.

Unified Numbering System (UNS)

Establishes 18 series numbers of metals and alloys. Each UNS number consists of  a single letter prefix followed by 5 digits. In most cases the alphabet is suggestive of the family of the  metal identified. 

A00001 – A99999 – Aluminum and Aluminum alloys
C00001 – C99999 – Copper and Copper Alloys
E00001 – E99999 – Rare earth and rare earth like metals and alloys
L00001 – L99999 – Low Melting metals and alloys
M00001 – M99999 – Miscellaneous non-ferrous metals and alloys
N00001 – N99999 – Nickel and Nickel Alloys
P00001 – P99999 – Precious Metals and Alloys
R00001 – R99999 – Reactive and Refractory metals and alloys
Z00001 – Z99999 – Zinc and zinc alloys
D00001 – D99999 – Specified mechanical properties of Steel
F00001 – F99999 – Cast Iron and Cast Steel
G00001 – G99999 – AISI and ASE Carbon and alloy steels
H00001 – H99999 – AISI H Steels
J00001 – J99999 – Cast Steel
K00001 – K99999 – Miscellaneous Steels and Ferrous alloys
S00001 – S99999 – Stainless Steel
T00001 – T99999 – Tool Steel

W00001 – W99999 – Welding Filler Metals and Electrodes

American Welding Society (AWS) :
These standards provide information on the welding fundamentals, weld design,  welder’s training qualifications, testing and inspection of the welds and guidance on the application and use  of welds. Individual electrode manufacturers have given their own brand names for the various electrodes and  the same are sold under these names.
American Water Works Association (AWWA) : 
These standards refer to the piping elements required for low  pressure water services. These are less stringent than other standards. Valves, Flanges etc., required for  large diameter water pipelines are covered under this standard and are refereed rarely by piping engineers.
C-500 : Gate Valves for Water and sewage system
C-510 : Cast Iron Sluice Gate Valves
C-504 : Rubber Seated Butterfly Valves
C-507 : Ball Valves 6″ to 48″
C-508 : Swing Check Valves 2″ to 24″
C-509 : Resilient Seated Gate Valves for water and sewage
The manufacturers Standardization Society of Valves and Fitting Industry – Standard Practices (MSS-SP) :
In  addition to the above standards and material codes, there are standard practices followed by manufacturers.  These are published as advisory standards and are widely followed. The most common MSS-SP standards referred  for piping are :
MSS-SP-6 : Standard Finishes for contact surface for flanges
MSS-SP-25 : Standard marking system for valves, fittings, flanges
MSS-SP-42 : Class 150 corrosion resistant gate, globe and check valves
MSS-SP-43 : Wrought stainless steel buttweld fittings
MSS-SP-56 : Pipe hanger supports – Material, design and manufacture
MSS-SP-61 : Pressure testing of valves
MSS-SP-67 : Butterfly Valves
MSS-SP-68 : High Pressure off seat butterfly valves
MSS-SP-69 : Pipe hanger supports – selection and applications
MSS-SP-70 : Cast iron gate valves
MSS-SP-71 : Cast iron check valves
MSS-SP-72 : Ball Valves
MSS-SP-78 : Cast iron plug valves
MSS-SP-80 : Bronze gate, globe and check valves
MSS-SP-81 : Stainless steel bonnetless knife gate valves
MSS-SP-83 : Pipe unions
MSS-SP-85 : Cast iron globe valves
MSS-SP-88 : Diaphragm valves
MSS-SP-89 : Pipe hangers and supports – fabrication and installation practices
MSS-SP-90 : Pipe hangers and supports – guidelines on terminology
MSS-SP-92 : MSS valves user guide
MSS-SP-108 : Resilient seated eccentric CI plug valves

In many instances, it is possible to find a British Standard which may be substitutes for  American Standards. For example, BS 2080 (British Standard for Face to Face or End to End dimensions of valves)  is identical to ANSI/ASME B16.10. Similarly BS 3799 and ANSI/ASME B 16.11 also compare.

The most commonly referred British Standards in the Piping Industry are :
BS 10 : Flanges
BS 806 : Pipes and Fittings for Boilers
BS 916 : Black Bolts, Nuts and Screws
BS 970 : Steel for Forging, Bars, Rods, valve steel
BS 1212 : Specification for Float Operated Valves
BS 1306 : Copper and Copper alooy pressure piping system
BS 1414 : Gate Valves for Petroleum Industry
BS 1560 : Steel Pipe Flanges
BS 1600 : Dimensions of Steel Pipes
BS 1640 : Butt Welding Fittings
BS 1740 : Wrought Steel screwed pipe fittings
BS 1868 : Steel Check Valves for Petroleum Industry
BS 1873 : Steel Globe and Check Valves for Petroleum Industry
BS 1965 : Butt welding pipe fittings
BS 2080 : Face to Face / End to End dimensions of Valves
BS 2598 : Glass Pipelines and Fittings
BS 3059 : Boiler and Superheater Tubes
BS 3063 : Dimensions of Gaskets for Pipe Flanges
BS 3381 : Metallic Spiral Wound Gaskets
BS 3600 : Dimensions of Welded and Seamless Pipes and Tubes
BS 3601 : C.S. Pipes and Tubes for pressure purposes at room temperature
BS 3602 : C.S. Pipes and Tubes for pressure purposes at high temperature
BS 3603 : C.S. and Alloy Steel Pipes and Tubes for pressure purposes at low temperature
BS 3604 : Alloy Steel Pipes and Tubes for high temperature
BS 3605 : SS Pipes and Tubes for pressure purposes
BS 3799 : Socket Weld / Screwed Fittings
BS 3974 : Pipe hangers, Slides and Roller type supports
BS 4346 : PVC pressure pipe – joints and fittings
BS 4504 : Steel, Cast Iron and Copper alloy fittings
BS 5150 : Cast Iron Wedge and Double Disc Gate Valves for general purposes
BS 5151 : Cast Iron Gate (parallel slide) Valves for general purposes
BS 5152 : Cast Iron Globe and Check Valves for general purposes
BS 5153 : Cast Iron Check Valves for general purposes
BS 5154 : Copper alloy Globe, Gate and Check Valves
BS 5155 : Cast Iron and Cast Steel Butterfly Valves for general purposes
BS 5156 : Diaphragm Valves for general purposes
BS 5157 : Steel Gate (parallel slide) Valves for general purposes
BS 5158 : Cast Iron and Cast Steel Plug Valves for general purposes
BS 5159 : Cast Iron and Cast Steel Ball Valves for general purposes
BS 5160 :  Flanged Steel Globe and Check Valves for general purposes
BS 5163 : Flanged Cast Iron Wedge Gate Valves for general purposes
BS 5351 : Steel Ball Valves for Petroleum Industry
BS 5352 : Steel Gate, Globe and Check Valves, smaller than 2″ NB
BS 5353 : Specifications for Plug Valves
BS 5391 : Specifications for ABS pressure pipes
BS 5392 : Specifications for ABS fittings
BS 5433 : Specifications for underground stop valves for water services
BS 5480 : Specifications for GRP pipes and fittings
BS 6364 : Specifications for Valves for Cryogenic services
BS 6755 : Testing of Valves
BS 6759 : Safety Valves

Bureau of Indian Standards (BIS)

have so far not developed an Indian Standard for the  design of Piping Systems. Hence, ANSI Standards ASME 31.1 and 31.3 are widely used for the design. These  standards also accept materials covered in other standards. Unlike American Standards, Indian Standards cover  dimensions and material specifications under the same standard number. There are no groupings based on branch  of engineering. Some of the most commonly referred Indian Standards by Piping Engineers are : 

IS 210 : Grey Iron Castings
IS 226 : Structural Steel (superseded by IS 2062)
IS 554 : Dimensions of Pipe Threads
IS 778 : Specification for Copper Alloy Gate, Globe and Check Valves
IS 780 : Specification for Sluice Valves – 50 NB to 300 NB
IS 1239 (Part I and II) : Specification for Mild Steel tubes and fittings
IS 1363 : Hexagonal Bolts, Screws and nuts – Grade C
IS 1364 : Hexagonal Bolts, Screws and nuts – Grade A and B
IS 1367 : Technical supply conditions for threaded steel fastners
IS 1536 : Centrifugally Cast Iron Pipes
IS 1537 : Vertically Cast Iron Pipes
IS 1538 : Cast Iron Fittings
IS 1870 : Comparison of Indian and Overseas Standards
IS 1879 : Malleable Iron Pipe Fittings
IS 1978 : Line Pipe
IS 1979 : High Test Line Pipe
IS 2002 : Steel Plates
IS 2016 : Plain Washers
IS 2041 : Steel Plates for Pressure Vessels used at moderate and low temperature
IS 2062 : Steel for general structural purposes
IS 2379 : Colour Code for Identification of Pipelines
IS 2712 : Compressed Asbestos Fibre Jointing
IS 2825 : Code for Unfired Pressure Vessels
IS 2906 : Specification for Sluice Valves – 350 NB to 1200 NB
IS 3076 : Specification for LDPE Pipes
IS 3114 : Code of Practice for laying pipes
IS 3516 : Cast Iron flanges and flanged fittings for Petroleum Industry
IS 3589 : Seamless or ERW Pipes (150 NB to 2000 NB)
IS 4038 : Specifications for Foot Valves
IS 4179 : Sizes for pressure vessels and leading dimensions
IS 4853 : Radiographic Examination of Butt Weld Joints in pipes
IS 4864 to IS 4870 : Shell Flanges for vessels and equipments
IS 4984 : Specification for HDPE Pipes
IS 4985 : Specification for PVC Pipes
IS 5312 : Specification for Check Valves
IS 5572 : Classification of Hazardous area for Electrical Installation
IS 5822 : Code of practice for laying welded steel pipes
IS 6157 : Inspection and Testing of Valve
IS 6286 : Seamless and Welded pipes for Subzero temperatures
IS 6392 : Steel Pipe Flanges
IS 6630 : Seamless alloy steel pipes for high temperature service
IS 6913 : Stainless Steel tubes for food and beve rage industry
IS 7181 : Horizontally cast iron pipes
IS 7240 : Code of Proctice for Cold Insulation
IS 7413 : Code of Proctice for Hot Insulation
IS 7719 : Metallic spiral wound gaskets
IS 7806 : Stainless Steel Castings
IS 7899 : Alloy Steel castings for pressure services
IS 8008 : Specification for moulded HDPE Fittings
IS 8360 : Specification for fabricated HDPE Fittings
IS 9890 : Ball Valves for general purposes
IS 10221 : Code of Proctice for coating and wrapping of underground MS pipelines
IS 10592 : Eye wash and safety showers
IS 10605 : Steel Globe Valves for Petroleum Industries
IS 10611 : Steel Gate Valves for Petroleum Industries
IS 10711 : Size of Drawing Sheets
IS 10805 : Foot Valves
IS 10989 : Cast / Forged Steel Check Valves for Petroleum Industry
IS 10990 : Technical drawings – Simplified representation of pipelines
IS 11790 : Code of Proctice for preparation of Butt welding ends for valves, flanges and fittings
IS 11791 : Diaphragm Valves for general purposes
IS 11792 : Steel Ball Valves for Petroleum Industry
IS 12709 : Specifications for GRP pipes
IS 13049 : Specifications for Diaphragm type float operated valves
IS 13095 : Butterfly Valves
IS 13257 : Ring type joint gasket and grooves for flanges

There are certain other international standards, which are also referred in Piping Industry. These are DIN  standards of Germany and JIS standards of Japan. DIN standards are more popular and equivalent.

Periodic review of the standards by the committee are done and these are revised to incorporate the modified  features based on the research and feedback from industry. It is, hence, necessary that the latest editions of  the codes and standards are referred for the design.


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