Carbon steel pipe as a pressure vessel and pipeline core material, its weight size in petrochemical, construction machinery manufacturing and other fields is very big impact, will directly affect the project costing, transportation program design and structural load-bearing safety. This article provides carbon steel pipe weight calculation formula, industry standard comparison and actual engineering cases, to help you better understand the relevant knowledge of carbon steel pipe.
Carbon Steel Pipe Base Parameters and Weight Relationship
Material Density Differences
Carbon steel is divided into three categories according to its carbon content: low, medium and high carbon steel.
|
Carbon Steel Types |
densities |
|
Mild steel (C≤0.25%) |
7.85 g/cm³ |
|
Medium carbon steel (C 0.25%-0.60%) |
· 7.87 g/cm³ |
|
High carbon steel (C≥0.60%) |
· 7.90 g/cm³ |
Taking DN100 Sch40 as an example, for every 0.01 g/cm³ increase in the density of the material, the weight of each meter of pipe increases by about 0.12%.
Geometric parameter specification
- Outside diameter (OD): need to be measured according to ASME B36.10 standard (such as 6-inch pipe OD for 168.3mm).
- Wall Thickness (WT): Common wall thickness grade Sch 40, Sch 80 corresponding values need to refer to the standard thickness table.
- Length unit conversion: 1 foot = 0.3048 meters, need to pay attention to the formula of uniform units.
Quick Check Unit Weight of Carbon Steel Pipe
|
Specifications (inches) |
Sch 40 Weight (kg/m) |
Sch 80 Weight (kg/m) |
|
2″ |
5.02 |
7.62 |
|
4″ |
16.07 |
21.44 |
|
6″ |
31.21 |
45.03 |
Weight Calculation Formulas and Tools
Online Steel Pipe Weight Calculator
Steel Pipe Weight Calculator
Weight: 0 kg
Analysis of the core formula
Theoretical weight formula for carbon steel pipe:
Weight (kg) = (OD – WT) × WT × 0.02466 × Length
OD: outer diameter (mm)
WT: wall thickness (mm)
Length: Length (m)
Example Calculation:
Calculate the weight of a single 6-inch Sch 40 carbon steel pipe (OD = 168.3mm, WT = 7.11mm) (length 6 meters):
(168.3 – 7.11) × 7.11 × 0.02466 × 6
Weight influencing factors in practical engineering
Corrosion and wear
According to the NACE International study, the average annual corrosion rate of carbon steel pipes in sulfur-containing environments amounts to 0.5 mm/year, resulting in a weight loss of approximately 6.2 kg/m-year (DN200 Sch40, for example). Corrosion allowance needs to be made in the design.
Welding process deviations
The thickness of the weld area of ERW (resistance welding) pipes is usually increased by 0.1-0.3 mm, resulting in a weight deviation of about 0.5%-1.2% for a single pipe. In nuclear power projects, it is required that the weld thickness increase error is ≤0.15mm.
Case Comparison
|
Project Type |
Allowable Weight Tolerance |
Basis for acceptance criteria |
|
Boiler high pressure piping |
±2% |
ASME B31.1 |
|
Oil and gas pipelines |
±3% |
API 5L Section 8 |
Comparison of industry standards (API/ASTM/ISO)
API 5L
It is required that the deviation of the actual weight of the pipe from the theoretical value is ≤±3.5% (PSL1 grade) or ≤±2.5% (PSL2 grade).
Theoretical weight, length and production lot number should be marked on the pipe body.
ASTM A106
Seamless carbon steel pipe for high temperature with weight tolerance of +10%/-3.5% (for length > 7.6 meters).
ISO 3183
The weight marking is required for international shipments to contain kg/m and total weight (tons) in units accurate to two decimal places.
