Calculation of flange weight
The calculation of flange weight is crucial for determining material requirements, manufacturing costs, and subsequent installation processes.
Below are the steps and corresponding calculations for determining the weight of plate flanges and weld neck flanges based on their geometric characteristics:
Weight Calculation of Plate Flanges
To calculate the weight of plate flanges, consider the following parameters:
- Outside Diameter (A1)
- Inside Diameter (B1)
- Sheet Thickness (C)
- Number of Drill Holes (D1)
- Drill Hole Diameter (C1)
The weight of the plate flange can be calculated by determining the volume of the flange and then multiplying it by the material’s density.
The formula gives the volume of the flange (V):
V = 4/ * (A12 – B21 – D21 – C21) * C
Then, use the density (ρ) of the material (e.g., for 304 stainless steel, ρ= 7.93 * 10-6 kg/cm3) to calculate weight (W):
W = V * ρ
By plugging in the values, you get:
W = 4/ * (A12 – B21 – D21 – C21) * C * 7.93 * 10-6
Weight Calculation of Weld Neck Flanges
The weight calculation of welding neck flange (WN flange for short) can be divided into several geometric parts. Here, we will use mathematical modeling methods combined with geometric features to theoretically calculate the weight of the welded neck flange. To clearly illustrate this calculation process, we will also provide corresponding graphic representations, including the main dimensions of the flange and the weight calculation model of the corresponding parts.
The drawing should follow the ASME B16.5 standard and include the overall length (H) of the welded neck flange, the minimum thickness (T) of the flange, the height of the raised surface (t), the outer diameter of the flange (D), the diameter of the bolt ring (K), the outer diameter of the raised surface (G), the diameter of the flange (B), the diameter of the flange (A), the root diameter of the flange (X), the number of bolt holes (n), and the diameter of the bolt holes (L).
Next, I can provide you with a simplified schematic diagram of the welding neck flange, which will help you visualize these calculation parts. Please wait a moment, I will create this chart for you. The following is a simplified schematic diagram of the weight calculation and various parts of the welded neck flange (WN flange):
The calculation method described here divides the welding neck flange into four parts:
Part I – Similar to short pipe sections, with a straight length of 10mm according to ASME B16.5 standards. The weight calculation formula is as follows:
W1 = 0.0246615 * (A – Tk) * Tk * 0.01
- Tk – wall thickness of the mating pipe
This represents the wall thickness of the pipeline that matches it.
Part II – can be seen as a truncated cone. The weight calculation formula is:
W2 = {1/3 * π * (H – T – t – 0.01) * [(X/2)2 + (A/2)2 + X * A/4)] – 1/4 * π * B2 * (H – T – t – 0.01)} * ρ
Part III – is a large cylinder minus several small cylinders (bolt holes and inner holes):
W3 = 1/4 * π * (D2 – B2 – n * L2) * T * ρ
Part IV – Convex part, which can be regarded as one cylinder minus another cylinder (inner hole):
W4 = 1/4 * π * (G2 – B2) * t * ρ
The total weight of the welded neck flange is calculated as:
W = W1 + W2 + W3 + W4
Among them, represents the density of the material.