Codes, Standards and Recommended Practices

Standardization is the process of implementing and developing technical documents based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization can, and does, reduce the cost, inconvenience, and confusion that results from unnecessary and undesirable differences in equipment, systems, materials and procedures.  Standards can also document accepted industry practice in areas such as safety, testing and erection. In process plants standardization is achieved by implementation of various standards, codes and recommended practices.

Standards

Standards are the documents, prepared by a professional societies or committee, which are believed to be efficient engineering practices and which contain mandatory requirements. The users are responsible for correct application of the same. Compliance with the standard does not itself confer immunity from legal obligations.

Code

Code is a group of general rules or systematic procedures for design, fabrication, installation and inspection that are adopted by legal jurisdiction and made into law. Codes are intended to set forth engineering requirements deemed necessary for safe design and construction of piping installations. A code has the force of law unlike standards which are voluntarily accepted guidelines which become mandatory only when incorporated into a business contract.

Recommended Practices

Recommended practices are documents prepared by professional group or committee indicating good engineering practices but which are optional. Companies also develop their own recommended practices in order to have consistency in design and to avoid having one project differ substantially from others.

Each country has its own Codes and Standards. The major organizations for standards are shown in Figure 1.

Figue 1.

Advantages of Working with Code and Standards

• They establish a commonality in engineering criteria, terms, principles, practices, materials, processes, etc.
• They help user establish a standard way of working.
• They ensure built in safety, reliability and continuity.
• They minimize mismatches and promote interchangeability.
• They economize the system, reduce inventory and ensure readily available backup from market.
• They help in accumulation of knowledge.
• They help in avoiding reinventing the wheel again.

Few generally referred standards by Piping Engineers are listed below;

The American Petroleum Institute (API) Standards

• 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) Standard

• AISI 410 – 13% Chromium Alloy Steel
• AISI 304 – 18/8 Austenitic Stainless Steel
• AISI 316 – 18/8/3 Austenitic Stainless Steel

The American National Standards Institute (ANSI) Standards

• ASME B31.1 – Power Piping

• ASME B31.2 – Fuel Gas Piping

• ASME B31.3 – Process Piping

• ASME B31.4 – Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids

• ASME B31.5 – Refrigeration Piping and Heat Transfer Components

• ASME B31.8 – Gas Transmission and Distribution Piping Systems

• ASME B31.8S- Managing System Integrity of Gas Pipelines

• ASME B31.9 – Building Services Piping

• ASME B31.11 – Slurry Transportation Piping Systems

  Other major ANSI / ASME Standards refereed for the piping elements are :

• ANSI B 1.1 – Unified Inch Screw Threads
• ANSI / ASME B 1.20.1 – Pipe threads for general purposes
• ANSI / ASME B 16.1 – Cast Iron Pipe Flanges and Flanged Fittings
• ANSI / ASME B 16.3 – Malleable Iron Threaded Fittings
• ANSI / ASME B 16.4 – Cast Iron Threaded Fittings
• ANSI / ASME B 16.5 – Steel Pipe Flanges and Flanged Fittings
• ANSI / ASME B 16.9 – Steel Butt Welding Fittings
• ANSI / ASME B 16.10 – Face to Face and End to End dimensions of Valves
• ANSI / ASME B 16.11 – Forged Steel Socket Welding and Threaded fittings
• ANSI B 16.20 – Metallic Gaskets for Pipe Flanges – ring joint, spiral wound
• ANSI / ASME B 16.21 – Non Metallic Gaskets for Pipe Flanges
• ANSI / ASME B 16.25 – Butt Welding Ends
• ANSI / ASME B 16.28 – Short Radius Elbows and Returns
• ANSI / ASME B 16.34 – Steel Valves, Flanged and butt welding ends
• ANSI / ASME B 16.42 – Ductile Iron Pipe Flanges and Flanged Fittings – Class 150# and 300#
• ANSI / ASME B 16.47 – Large Diameter Steel Flanges – NPS – 26″ to 60″
• ANSI / ASME B 18.2 1 and 2 – Square and Hexagonal head Bolts and Nuts (Inch and mm)
• ANSI / ASME B 36.10 – Welded and Seamless Wrought Steel Pipes
• ANSI / ASME B 36.19 – Welded and Seamless Austinitic Stainless Steel Pipe

The American Society for Testing and Materials (ASTM) Standards

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.

• Part A – Ferrous Materials
• Part B – Non-Ferrous Materials
• Part C – Welding Materials
• Part D – Properties of Materials

American Welding Society (AWS) Standards

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) Standards

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-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
• C-510 : Cast Iron Sluice Gate Valves

The manufacturers Standardization Society of Valves and Fitting Industry – Standard Practices (MSS-SP) Standards

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 butt weld 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 bonnet-less 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

British Standards

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.

There are certain British Standards referred by Indian Manufacturers for Piping and Valves. 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, etc.
• BS 1212 : Specification for Float Operated Valves
• BS 1306 : Copper and Copper alloy 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 Super-heater 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

Indian Standards

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 : Color Code for Identification of Pipelines
• IS 2712 : Compressed Asbestos Fiber 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 beverage industry
• IS 7181 : Horizontally cast iron pipes
• IS 7240 : Code of Practice for Cold Insulation
• IS 7413 : Code of Practice 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 molded HDPE Fittings
• IS 8360 : Specification for fabricated HDPE Fittings
• IS 9890 : Ball Valves for general purposes
• IS 10221 : Code of Practice 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 Practice 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