Pipe Weight Calculation is a very important parameter in piping engineering. Pipe weight is directly related to its thickness (Pipe Schedule).
Pipe Weight Calculation Formula And Excel Sheet | Steel Pipe Weight Chart
The more the pipe thickness or pipe schedule the more is the pipe weight. The more the pipe weight, the more will be its rigidity and less flexibility. More pipe weight means more cost of procurement. More pipe weights adds more loads on the pipe supports requiring more robust structural member requirements. So, we can say pipe weight is related to overall plant cost in some way. In this article, we will explore the pipe weight calculation methodologies.
Pipe Weight Calculation Formula
Mass (M)= Density (D) X Volume (V) …(eqn. 1)
Also, there are two other terms associated with pipe weight calculation. These are
- Empty Pipe Weight Calculation and
- Water filled Pipe Weight Calculation.
Empty Pipe Weight Calculation
So following eqn. 1 above we have to calculate the volume (V) of the pipe first and then we have to multiply the calculated volume with pipe material density (D) in consistent unit. To calculate the volume of the pipe we need the following parameters:
- Pipe Outside Diameter (OD) (Obtained from ASME B 36.10M / ASME B 36.19M)
- Pipe Thickness (T) (Obtained from ASME B 36.10M / ASME B 36.19M), and
- Length of Pipe (=1 as pipe weight is expressed in pipe weight per unit length)
- The inside diameter (ID) of the pipe can easily be calculated as ID=OD-2T
- Pipe Metal Cross Section is calculated as Π (OD2-ID2)/4
The volume (V) of the pipe is calculated as V=Pipe metal cross-sectional area X length of pipe = {Π (OD2-ID2)/4} * 1
Let’s calculate the weight of a 6 inch CS pipe with Sch. 40 as pipe thickness. From ASME B 36.10M
- Pipe OD=168.3 mm
- Pipe Thickness=7.11 mm
- Hence, ID=168.3-27.11=154.08 mm Metal Cross Sectional Area=(Π)(168.32 – 154.082)/4=3600.4565 mm2
- So volume for a unit length of pipe=3600.4565 * 1= 3600.4565 mm3 =(3600.4565/1000000) =0.0036004565 m3
So now we have to multiply this volume by CS pipe density (7850Kg/m3) to get the actual weight of 1 m of pipe length.
So Metal weight of 1 m of Pipe length=0.0036004565*7850=28.26358356 Kg.
To calculate the pipe weight for more lengths simply multiply the above value with the actual length of the pipe.
Similarly, we can calculate an empty pipe weight per foot of length by considering all the above values in a consistent FPS unit system.
Water-Filled Pipe Weight
Water filled pipe weight is required to calculate the loads during hydro testing. For the structural supporting design of non-critical lines, pipe loads are calculated or approximated based on water-filled pipe weight.
To calculate content (water) weight inside the pipe we have to multiply the water density (1000 Kg/m3) with internal pipe cross-sectional volume 1*(Π * ID2)/4.
For the above pipe under consideration, the internal pipe cross-sectional area=Π*154.082/4=18645.86008 mm2=18645.86008/1000000=0.01864586006 m2
So weight of water content inside the pipe per meter of length=1000*0.01864586006=18.64586 Kg/m.
Now add this content weight with the metal pipe weight to get the total water filled pipe weight. So,
Water-filled Pipe Weight (Kg/m)=Weight of empty pipe (Kg/m)+ Weight of Content (Kg/m)
In the above example, Water filled pipe weight=28.26+18.65=46.91 Kg/m
By simply multiplying the above value (46.91 Kg/m) with the actual pipe length you can calculate the water filled pipe weight in Kg.
Steel Pipe Weight Chart
For Carbon Steel and Stainless Steel pipes, the pipe weight per foot or pipe weight per meter of length can easily be taken directly from the Steel Pipe Weight Chart Provided in ASME B 36.10M (For Carbon Steel) or ASME B 36.19M (For Stainless Steel).
Those two ASME codes provide the Steel pipe weights directly in their tables as pipe weight per foot or pipe weight per meter of length. Part of the table from ASME B 36.10M for a 6-inch line that we considered above as an example is produced here to explain the chart.
As you can see that the empty pipe weight that we calculated for 6-inch Sch. 40 pipe is matching exactly with the value provided in the above ASME Code.
However, the above steel pipe weight chart provides only the empty pipe weight value directly. Water-filled pipe weight you have to manually calculate using the above procedure.
Pipe Weight Calculation using Pipedata-Pro
Both Empty pipe weight and Water-filled pipe weight can easily be obtained if you have Pipedata-Pro software. That software directly gives the pipe weight values of all pipe sizes corresponding to pipe thicknesses. Fig. 3 shows the sample pipe data-Pro Screenshot for the 6 inches Sch. 40 pipe that we considered in our pipe weight calculation.
The above values are showing in pipe weight in Kg/m. However, You can easily change the unit if you need data for Pipe weight per foot.
Please Download File Excel Sheet
