The pressure-bearing capacity of seamless steel tubes is a crucial parameter in engineering selection, and its calculation is based on principles of material mechanics and industry standard specifications. Understanding how this capacity is calculated helps users make scientific selections and ensure operational safety.

Fundamental Principle of Pressure Calculation

The calculation of the pressure-bearing capacity for seamless steel tubes primarily relies on the thin-walled cylinder theory, using Barlow's formula: P = 2St / D. Here, P is the theoretical pressure-bearing capacity (MPa), S is the allowable stress of the material (MPa), t is the wall thickness (mm), and D is the outside diameter (mm). This formula serves as the foundation for calculating the pressure-bearing capacity of seamless steel tubes in engineering practice.

In practical applications, a safety factor must also be considered. Depending on the specific usage scenario and required safety level, the safety factor typically ranges from 1.5 to 3.0. The technical team at Tenjan Tube Co., Ltd. strictly adheres to relevant standards to determine the appropriate safety factor when assisting customers with product selection, ensuring safe use.

Analysis of Key Parameter Influences

The material's allowable stress is a key factor determining the pressure-bearing capacity of seamless steel tubes. Allowable stress values vary significantly for different materials. For instance, the allowable stress for Grade 20 steel at room temperature is approximately 130 MPa, while for alloy steel, it can exceed 200 MPa. Through precise material control and heat treatment processes, Tenjan Tube Co., Ltd. ensures its products meet the required mechanical properties per standards.

The influence of geometric dimensions on pressure-bearing capacity is equally important. Under the same outside diameter condition, doubling the wall thickness doubles the pressure-bearing capacity. Conversely, under the same wall thickness condition, a smaller outside diameter results in a higher pressure-bearing capacity. This relationship requires particular attention during the selection of seamless steel tubes.

Calculation Example and Selection Suggestions

Taking a DN100 seamless steel tube as an example: outside diameter 108mm, wall thickness 4mm, material Grade 20 steel. The theoretical pressure-bearing capacity is calculated as follows: P = 2 × 130 × 4 / 108 ≈ 9.6 MPa. After considering the safety factor, the actual service pressure should be controlled within the range of 3.2 - 6.4 MPa.

Tenjan Tube Co., Ltd. recommends that users consider not only the working pressure during selection but also factors such as pressure fluctuations, temperature variations, and medium characteristics. For conditions involving pressure shocks, the safety factor should be appropriately increased. In high-temperature environments, the degradation of material strength needs to be considered.

Standard Specifications and Practical Application

Different application fields have specific standard requirements for the pressure calculation of seamless steel tubes. GB/T 20801 applies to industrial piping, while ASME B31.3 is suitable for process piping. Each standard provides detailed rules for allowable stress values and calculations. The technical staff at Tenjan Tube Co., Ltd. are familiar with various standards and can provide professional calculation and selection services for customers.

In practical engineering, besides theoretical calculations, verification through hydrostatic tests is also required. The test pressure is generally 1.5 times the design pressure, ensuring the safety of the seamless steel tube in actual use. Every batch of the company's products undergoes strict hydrostatic testing to guarantee they meet the specified pressure-bearing capacity.

Conclusion

Calculating the pressure-bearing capacity of seamless steel tubes is a systematic project that requires comprehensive consideration of multiple factors, including material properties, geometric dimensions, and service conditions. Leveraging a professional technical team and a robust quality system, Tenjan Tube Co., Ltd. provides accurate pressure calculations and reliable product assurance, ensuring that the most suitable seamless steel tube products are selected for every project.