Pipe Weight & Hanger Load Calculator
Weight per metre of pipe, contents, insulation, and cladding, the resulting support load, and the hanger rod size to carry it per MSS SP-58.
When to use this calculator
Use to turn a line description into the numbers a support designer needs: distributed weight for span calculations, the load at each hanger, and the rod diameter that carries it. It builds the weight up ring by ring — pipe metal, contents, insulation, cladding — and reports both the operating and the hydrotest case, which is what usually governs the support since a gas line full of water is far heavier than in service.
Required inputs
- Outside diameter and wall thickness, with the pipe material density
- Contents density — operating fluid, and water for the test case
- Insulation thickness and density; cladding thickness and density
- Support span, to convert the distributed weight into a point load
Expected outputs
- Weight per metre of each component and the total
- Governing weight — operating or hydrotest
- Support load F = w · g · L
- Smallest hanger rod whose MSS SP-58 safe load exceeds the support load
Formula overview
OD, ID, and thicknesses in mm; densities in kg/m³; weight in kg/m; span in m; load in N. Rod sizes and their safe loads come from MSS SP-58.
ID = OD − 2t
w_pipe = ρ_steel · π/4 · (OD² − ID²) · 10⁻⁶ kg/m
w_fluid = ρ_fluid · π/4 · ID² · 10⁻⁶ kg/m
w_ins, w_clad — the same ring form on their own radii
w_total = Σ rings, governing = max(operating, hydrotest)
F = w_gov · g · L
rod = smallest size with MSS SP-58 safe load ≥ FWorked example
6" Sch 40 carbon steel carrying water, 4 m span:
OD = 168.3 mm, t = 7.11 mm → ID = 154.08 mm, ρ_steel = 7 850 kg/m³
w_pipe = 7 850 × π/4 × (168.3² − 154.08²) × 10⁻⁶ = 28.3 kg/m
w_fluid = 998 × π/4 × 154.08² × 10⁻⁶ = 18.6 kg/m
w_total = 46.9 kg/m
F = 46.9 × 9.81 × 4 = 1 840 N per support
The water is 40% of the load — which is why a gas line still has to be
supported for its hydrotest condition.Common mistakes
- Supporting a gas or vapour line for its operating weight. During hydrotest that line is full of water, and the test case routinely governs both the hanger and the structure beneath it.
- Leaving insulation and cladding out. On a large cold or hot line the insulation ring and its metal cladding add a substantial fraction of the load, and cladding is dense enough to matter on its own.
- Sizing the rod on the distributed weight rather than the load. The rod carries w × g × span — halving the spacing halves the rod load, which is often cheaper than going up a rod size.
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