When it comes to selecting the right pipe for your project, understanding and adhering to industry standards is crucial. The British Standard BS 1387 is a widely recognized specification for steel tubes, pipes, and fittings for waterworks purposes. This comprehensive guide will walk you through the process of choosing the appropriate pipe size according to the BS 1387 standard, ensuring that your project meets the necessary requirements and performs optimally.
Clarify Application Requirements and Parameters
Before delving into the specifics of pipe selection, it's essential to have a clear understanding of your project's requirements and parameters. This initial step forms the foundation for making informed decisions throughout the pipe selection process.
Start by identifying the intended application of the pipes. Are they for water distribution, gas transportation, or structural purposes? Each application has its own set of requirements that will influence your choice. For instance, pipes used for potable water systems may need to meet additional health and safety standards, while those used in industrial settings might require higher pressure ratings.
Next, consider the environmental conditions in which the pipes will be installed and operated. Factors such as temperature, pressure, and exposure to corrosive substances can significantly impact the performance and longevity of the pipes. BS 1387 pipes are typically made of carbon steel, which offers good strength and durability but may require additional protection in harsh environments.
Another crucial parameter to consider is the flow rate and pressure requirements of your system. These factors will directly influence the pipe size and wall thickness needed to ensure efficient and safe operation. It's advisable to consult with a professional engineer or use appropriate calculation tools to determine the precise flow and pressure specifications for your project.
Lastly, take into account any space constraints or installation challenges that may affect your pipe selection. The physical limitations of your project site, such as available space for pipe runs or accessibility for maintenance, can impact the feasibility of certain pipe sizes or configurations.
By thoroughly examining these application requirements and parameters, you'll be better equipped to make informed decisions in the subsequent steps of the pipe selection process according to the BS 1387 standard.
Nominal Size (DN) and Outer Diameter Matching
Once you have a clear understanding of your project's requirements, the next step is to determine the appropriate nominal size (DN) and corresponding outer diameter of the pipes. The BS 1387 standard provides a standardized system for pipe sizing, which helps ensure compatibility and consistency across different manufacturers and installations.
The nominal size (DN) is a dimensionless designator that represents the approximate internal diameter of the pipe. It's important to note that the DN is not an exact measurement but rather a reference point used for classification. In the BS 1387 standard, nominal sizes typically range from DN 8 (1/4 inch) to DN 150 (6 inches).
To select the appropriate nominal size, consider the required flow rate and pressure drop calculations for your system. These calculations will help determine the minimum internal diameter needed to achieve the desired performance. Once you have this information, you can choose the nearest standard nominal size that meets or exceeds your requirements.
After determining the nominal size, you'll need to match it with the corresponding outer diameter. The BS 1387 standard provides a table that correlates nominal sizes with specific outer diameters. For example:
- DN 15 (1/2 inch) corresponds to an outer diameter of 21.3 mm
- DN 25 (1 inch) corresponds to an outer diameter of 33.7 mm
- DN 50 (2 inches) corresponds to an outer diameter of 60.3 mm
It's crucial to use the correct outer diameter when specifying or ordering pipes, as this ensures proper fitting with standard connectors and accessories. Additionally, the outer diameter plays a role in determining the pipe's strength and its ability to withstand internal pressure.
When working with BS 1387 pipes, it's important to note that the standard covers three different wall thickness grades: Light, Medium, and Heavy. Each grade has slightly different internal diameters for the same nominal size, which can affect flow characteristics. We'll explore this aspect in more detail in the next section.
By carefully matching the nominal size to the appropriate outer diameter, you ensure that your pipe selection aligns with industry standards and meets the specific requirements of your project. This standardization not only facilitates easier procurement and installation but also ensures long-term compatibility and ease of maintenance for your piping system.
Wall Thickness Grade Selection
The final crucial step in choosing the appropriate pipe size according to the BS 1387 standard is selecting the correct wall thickness grade. The standard specifies three grades of wall thickness: Light, Medium, and Heavy. Each grade offers different levels of strength and pressure resistance, allowing you to tailor your selection to the specific needs of your project.
Light Grade: This is the thinnest option available under BS 1387. Light grade pipes are suitable for low-pressure applications and situations where weight reduction is a priority. They are often used in less demanding environments or for secondary piping systems where the risk of mechanical damage is low.
Medium Grade: This is the most commonly used grade and offers a balance between strength and cost-effectiveness. Medium grade pipes are suitable for a wide range of applications, including general plumbing, heating systems, and many industrial uses. They provide good pressure resistance and durability for most standard installations.
Heavy Grade: As the name suggests, these pipes have the thickest walls and offer the highest strength and pressure resistance. Heavy grade pipes are ideal for high-pressure systems, applications with a risk of mechanical damage, or installations that require maximum durability. They are often used in industrial settings or for main supply lines where reliability is paramount.
To select the appropriate wall thickness grade, consider the following factors:
- Operating Pressure: Higher operating pressures generally require thicker wall grades to ensure safety and longevity.
- External Loads: If the pipes will be subject to significant external forces (e.g., buried pipes or those in high-traffic areas), a heavier grade may be necessary.
- Corrosion Allowance: In environments where corrosion is a concern, opting for a thicker wall grade can provide an additional safety margin.
- Cost Considerations: While heavier grades offer more strength, they also come at a higher cost. Balance the need for durability with budget constraints.
- Weight Limitations: In some applications, the weight of the piping system may be a critical factor. Lighter grades can help reduce overall system weight.
It's important to note that the internal diameter of the pipe varies slightly between different wall thickness grades for the same nominal size. This variation can affect flow characteristics, so it's essential to account for this in your system design calculations.
When specifying BS 1387 pipes, always clearly indicate both the nominal size and the wall thickness grade to ensure you receive the correct product. For example, a specification might read "DN 50 Medium Grade BS 1387 Pipe," which would indicate a pipe with a nominal size of 50 mm (2 inches) and medium wall thickness.
By carefully considering these factors and selecting the appropriate wall thickness grade, you can ensure that your piping system not only meets the requirements of the BS 1387 standard but also provides the optimal balance of performance, durability, and cost-effectiveness for your specific application.
Contact us
Choosing the appropriate pipe size according to the BS 1387 standard is a critical process that requires careful consideration of various factors. By clarifying your application requirements and parameters, matching the nominal size to the correct outer diameter, and selecting the appropriate wall thickness grade, you can ensure that your piping system meets industry standards and performs optimally for your specific needs.
Since 2003, LONGMA GROUP has been a leading player in China's steel pipe industry, achieving remarkable success. By the close of 2023, our annual output had surpassed one million tons. Our BS 1387 pipes are of top-notch quality, with outer diameters ranging from 3/8" to 18", thicknesses from SCH10 to SCH160, and we maintain a stock quantity of 10-50 tons, along with an annual production capacity of 50-100 tons. If you're interested in our high-quality 1387 pipes or need expert guidance on pipe selection, don't hesitate to contact us at info@longma-group.com. We're looking forward to building a fruitful business relationship with you and ensuring your project's success with our superior products and expertise.
References
- British Standards Institution. (2018). BS 1387:1985 - Specification for screwed and socketed steel tubes and tubulars and for plain end steel tubes suitable for welding or for screwing to BS 21 pipe threads.
- American Society of Mechanical Engineers. (2019). ASME B36.10M - Welded and Seamless Wrought Steel Pipe.
- International Organization for Standardization. (2015). ISO 4200:1991 - Plain end steel tubes, welded and seamless — General tables of dimensions and masses per unit length.
