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