NB Pipe Size Chart
The NB Pipe Size Chart by CeraPure Steel provides complete details of nominal bore pipe dimensions, outside diameter, wall thickness, schedules, and pipe weights used in industrial piping systems. NB (Nominal Bore) is a standard designation used for pipe sizing in industries such as oil & gas, pharmaceutical, dairy, chemical processing, power plants, and construction.
NB pipe sizes are commonly available in schedules like SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160, and XXS depending on pressure and application requirements.
What is NB in Pipe Size?
NB stands for Nominal Bore, which indicates the approximate internal diameter of a pipe. It is commonly expressed in inches and millimeters for international piping standards.
For example:
- 15 NB = 1/2 inch pipe
- 25 NB = 1 inch pipe
- 50 NB = 2 inch pipe
NB sizes are widely used in stainless steel pipes, carbon steel pipes, seamless pipes, welded pipes, and industrial tube systems.
Nominal Bore Pipe Formula
Pipe wall thickness and schedule are related to pressure handling capability.
Higher Schedule⇒Higher Wall Thickness\text{Higher Schedule} \Rightarrow \text{Higher Wall Thickness}Higher Schedule⇒Higher Wall Thickness
Thicker pipe walls provide better strength and pressure resistance for industrial applications.
NB Pipe Size Chart in MM & Inches
NB (MM) | NPS (Inch) | Outside Diameter (MM) |
6 NB | 1/8″ | 10.3 mm |
8 NB | 1/4″ | 13.7 mm |
10 NB | 3/8″ | 17.1 mm |
15 NB | 1/2″ | 21.3 mm |
20 NB | 3/4″ | 26.7 mm |
25 NB | 1″ | 33.4 mm |
32 NB | 1 1/4″ | 42.2 mm |
40 NB | 1 1/2″ | 48.3 mm |
50 NB | 2″ | 60.3 mm |
65 NB | 2 1/2″ | 73.0 mm |
80 NB | 3″ | 88.9 mm |
100 NB | 4″ | 114.3 mm |
125 NB | 5″ | 141.3 mm |
150 NB | 6″ | 168.3 mm |
200 NB | 8″ | 219.1 mm |
NB Pipe Schedule Chart
Pipe Size | SCH 5S | SCH 10S | SCH 40S | SCH 80S |
1/2″ | 1.65 mm | 2.11 mm | 2.77 mm | 3.73 mm |
3/4″ | 1.65 mm | 2.11 mm | 2.87 mm | 3.91 mm |
1″ | 1.65 mm | 2.77 mm | 3.38 mm | 4.55 mm |
1 1/4″ | 1.65 mm | 2.77 mm | 3.56 mm | 4.85 mm |
1 1/2″ | 1.65 mm | 2.77 mm | 3.68 mm | 5.08 mm |
2″ | 1.65 mm | 2.77 mm | 3.91 mm | 5.54 mm |
3″ | 2.11 mm | 3.05 mm | 5.49 mm | 7.62 mm |
4″ | 2.11 mm | 3.05 mm | 6.02 mm | 8.56 mm |
Nominal Bore Pipe Dimensions
Pipe Size | OD (MM) | SCH 40 Thickness | SCH 80 Thickness |
1/2″ | 21.3 | 2.77 mm | 3.73 mm |
3/4″ | 26.7 | 2.87 mm | 3.91 mm |
1″ | 33.4 | 3.38 mm | 4.55 mm |
1 1/4″ | 42.2 | 3.56 mm | 4.85 mm |
1 1/2″ | 48.3 | 3.68 mm | 5.08 mm |
2″ | 60.3 | 3.91 mm | 5.54 mm |
2 1/2″ | 73.0 | 5.16 mm | 7.01 mm |
3″ | 88.9 | 5.49 mm | 7.62 mm |
4″ | 114.3 | 6.02 mm | 8.56 mm |
NB Pipe Weight Formula
The weight of a pipe can be calculated using the following standard formula:
Weight (kg/m)=0.02466×(OD−WT)×WT\text{Weight (kg/m)} = 0.02466 \times (OD – WT) \times WTWeight (kg/m)=0.02466×(OD−WT)×WT
Where:
- OD = Outside Diameter
- WT = Wall Thickness
This formula is widely used in stainless steel and mild steel pipe calculations.
NB Pipe Weight Chart
NB Size | Pipe Size | SCH 40 Weight (Kg/M) | SCH 80 Weight (Kg/M) |
15 NB | 1/2″ | 1.27 | 1.62 |
20 NB | 3/4″ | 1.69 | 2.20 |
25 NB | 1″ | 2.50 | 3.24 |
32 NB | 1 1/4″ | 3.39 | 4.47 |
40 NB | 1 1/2″ | 4.05 | 5.41 |
50 NB | 2″ | 5.44 | 7.48 |
65 NB | 2 1/2″ | 8.63 | 11.41 |
80 NB | 3″ | 11.30 | 15.27 |
100 NB | 4″ | 16.07 | 22.32 |
DN to NPS Conversion Chart
DN (MM) | NPS (Inch) |
DN 6 | 1/8″ |
DN 8 | 1/4″ |
DN 10 | 3/8″ |
DN 15 | 1/2″ |
DN 20 | 3/4″ |
DN 25 | 1″ |
DN 32 | 1 1/4″ |
DN 40 | 1 1/2″ |
DN 50 | 2″ |
DN 65 | 2 1/2″ |
DN 80 | 3″ |
DN 100 | 4″ |
DN 150 | 6″ |
DN 200 | 8″ |
Types of NB Pipes
Stainless Steel NB Pipes
Used in pharmaceutical, food processing, and corrosive environments.
Carbon Steel NB Pipes
Suitable for structural and industrial applications.
Seamless NB Pipes
Manufactured without welding joints for high-pressure systems.
Welded NB Pipes
Cost-effective pipes used in general industrial applications.
ERW Pipes
Electric Resistance Welded pipes widely used in water and utility systems.
Applications of NB Pipes
Oil & Gas Industry
Used for fluid transportation and pressure systems.
Pharmaceutical Industry
Suitable for hygienic stainless steel piping systems.
Dairy & Food Processing
Used in sanitary process lines and fluid transfer systems.
Power Plants
Applied in steam and high-temperature piping.
Chemical Industry
Resistant to corrosion and chemical exposure.
Construction Industry
Used in fabrication and infrastructure projects.
Advantages of Using Standard NB Pipe Sizes
- Easy pipe identification
- International standard compatibility
- Accurate pressure calculations
- Better fitting compatibility
- Simplified engineering design
- Improved maintenance and replacement
- Cost-effective inventory management
Stainless Steel Pipe Standards
Standard | Description |
ASTM A312 | Stainless steel pipes |
ASTM A269 | Stainless steel tubing |
ASTM A213 | Boiler & heat exchanger tubes |
ASME B36.10 | Carbon steel pipe dimensions |
ASME B36.19 | Stainless steel pipe dimensions |
Industries Using NB Pipe Charts
- Petrochemical Plants
- Dairy Processing Units
- Pharmaceutical Plants
- Food & Beverage Industry
- Chemical Plants
- Fertilizer Plants
- Water Treatment Plants
- Shipbuilding Industry
- Power Generation Plants
Countries We Supply NB Pipes
CeraPure Steel supplies pipes and piping solutions globally including:
- India
- UAE
- Saudi Arabia
- Oman
- Qatar
- Kuwait
- Singapore
- United States
- United Kingdom
- Germany
- Australia
- South Africa
Conclusion
The NB Pipe Size Chart by CeraPure Steel helps engineers, fabricators, contractors, and industrial buyers select accurate nominal bore pipe dimensions for industrial applications. Understanding NB sizes, schedules, wall thicknesses, and pipe weights is essential for designing reliable piping systems with proper pressure handling and long-term performance.
CeraPure Steel offers high-quality stainless steel pipes, seamless pipes, welded pipes, sanitary tubing, and industrial piping products for global industries.
FAQs
What is NB in pipe size?
NB means Nominal Bore, which indicates the approximate internal diameter of a pipe.
What is the OD of a 1-inch NB pipe?
A 1-inch NB pipe has an outside diameter of 33.4 mm.
What is the difference between NB and DN?
NB is Nominal Bore used in inch-based systems, while DN (Diameter Nominal) is the metric equivalent.
Which schedule pipe is stronger?
Higher schedules like SCH 80 and SCH 160 are stronger because they have thicker walls.
Which industries use NB pipes?
NB pipes are used in oil & gas, pharmaceuticals, dairy, food processing, construction, and chemical industries.
How is pipe weight calculated?
Pipe weight is calculated using OD, wall thickness, and material density.