Pipe & Pipe size chart

 What is Pipe?

        Pipe refers to a hollow, usually cylindrical body of metal, plastic material used for conveying or transporting liquid and gases.

What are the Pipe Designations?

        NPS, NB, DN are the designations of the pipe and are used for writing specifications for ordering purpose.
        NPS, NB, DN are not exact inside or outside diameters.

• NPS = Nominal Pipe Size
• NB = Nominal Bore
• DN = Nominal Diameter

What are the types of pipes by manufacturing?

        ERW (Electric Resistance Welding)

• Used in general services like water & air
• Joint efficiency = 0.85 as per ASME B31.3, Table A-1B

        EFW (Electric Fusion Welding)

• Used  in High pressure & High temperature services (Except corrosive & Hazardous services)
• Joint efficiency = 0.95 (Normally)
                                    = 1.00 (After RT) 
• After 100% radiography EFW pipes can be used instead of seamless pipes.

       Seamless Pipe

• Used almost in all critical applications like,
• Pressure above 3.5 kg/cm2g
• Hazardous fluids
• Corrosive fluids
• High temperature services
• As per joining method or as per the type of ends,
• Plain end pipe
• Threaded end pipe
• Bevel end pipe
• Standard length of the pipes available in market
• SRL = Single Random Length =6m
• DRL = Double Random Length =12m

Pipe size chart

• Upto 12", NPS is near to inside diameter of pipe
• Above 12", NPS is equal to outside diameter of pipe
• example=> 14" x 25.4 = 355.6mm Which is mentioned in the above table
• 1 1/4", 2 1/2", 3 1/2", 5", 22" these are not commonly used pipe sizes. Because fittings for these sizes are not readily available in the market.
• Smallest Pipe size used in Oil & Gas industry is 1/2" NPS. 

Material Specifications

• CS (Carbon Steel) => A53, A106, A672, API 5L
• LTCS (Low Temperature Carbon Steel) => A333, A671
• LAS (Low Alloy Steel) => A335, A691
• SS304 (Stainless Steel) => A312 TP304, A358 TP304
• SS316                            => A312 TP316L, A358 TP316L    

    

Codes & Standards for Piping

Codes

Code is a document which is giving guidelines for Design, Construction & Installation. These guidelines are converted into law.

• The below are the codes that commonly used for Piping
• ASME B31.1 => Power Piping
• ASME B31.2 => Utility Piping
• ASME B31.3 => Process Piping
• ASME B31.4 => Liquid hydrocarbon transportation Pipeline
• ASME B31.5 => Refrigeration Piping and Heat transfer components
• ASME B31.8 => Gas transportation Pipeline
• ASME B31.8S => Managing System integrity of Gas Pipelines
• ASME B31.9 => Building services Piping 
• ASME B31.11=> Slurry transportation
• ASME B31.12=> Hydrogen Piping & Pipeline.

                    (ASME- American Society of Mechanical Engineers)

Standards

Standard is a document which is giving standard dimensions which are used for ease of interchangeability.

• Pipes (Ferritic steel) 
• CS/LTCS/LAS => ASME B36.10

• Stainless Steel (Austenitic steel) => ASME B36.19   
•  Fittings 
• Socket end fittings => ASME B16.11
• Threaded end fittings => ASME B16.11
• Buttweld end fitting => ASME B16.9
• Flanges
• Up to 24" => ASME B16.5
• Above 24" & Up to 60" => ASME B16.47 (Series A for Piping, Series B for Compact flanges mainly for rotating equipment's)
• 4" to 144" => AWWA (American Water Works Association)
• Orifice flanges => ASME B16.36  
• Gaskets
• Non Metallic => ASME B16.21
• Metallic => ASME B16.20
• Fasteners
• Stud Bolt & Machine Bolt => ASME B18.2.1
• Hex. Nut => ASME B18.2.2
• Spectacle Blind/Spacer/Blank => ASME B16.48
• Valves
• Socket welding & Threaded End => Length as per Manufacturing standard
• Buttweld, Flanged, Wafer End => Length as per ASME B16.10
• All valve design => ASME B16.34
• Standard for End preparation
• Socket Weld End preparation => ASME B16.11
• Butt Weld End preparation => ASME B16.25
• Threaded End preparation => ASME B1.20.1

Recommended Practices

            Guidelines set by the company or Group of companies, Number of such standard start with 'MSS'. Below are the few commonly used practices,

• MSS-SP-6 => Flange face finish
• MSS-SP-83 => Union
• MSS-SP-95 => Swage Nipples
• MSS-SP-97 => 'O' let fittings (Outlet fittings) 

            (MSS-SP => Manufacturing Standardization Society - Standard Practices)     

Piping Vs Pipeline

 The below listed points are common difference between Piping and Pipeline.

What is Piping?

• The engineering  discipline of piping design studies the efficient layout of the plant and transport of fluid inside the plant using pipes and other components.
• Pipe refers to a hollow, usually cylindrical body of metal, Plastic material used for conveying or transporting liquid and gases.

A sample image from a plant piping