The Site
Site layout — Network Way, the Brac cul-de-sac and the five plots (4 × semi-detached + 1 × detached). Existing main shown in red; roads unmade.
A practical low-pressure network design exercise: size and design a new gas supply main to a small housing development, working within real pressure, demand and network-analysis constraints.
A housing developer has requested a new gas supply from your network to a planned development (unmade roads) comprising 4 semi-detached and 1 detached property.
Given that the gas services to the properties will have a maximum pressure drop of 1 mbar, produce a design for the supply main.
Site layout — Network Way, the Brac cul-de-sac and the five plots (4 × semi-detached + 1 × detached). Existing main shown in red; roads unmade.
Semi-detached — max demand
4.5 m³ hr⁻¹
Detached — max demand
7 m³ hr⁻¹
Max pressure drop (services)
1 mbar
Efficiency
0.95
Bends & fittings allowance
10%
Diversity
Do not allow
Max Take-Off Allowable
50 m³ hr⁻¹
std
Max Pressure Available
55 mbar
Min Pressure Available
37 mbar
Calculate the peak demand for the development (no diversity).
Design the supply main — select material, diameter and route — to serve all five plots.
Confirm the design works within the available pressures (37–55 mbar) and the 1 mbar service drop, allowing 10% for bends & fittings and an efficiency of 0.95.
Check the total take-off against the maximum allowable of 50 m³ hr⁻¹ (std).
The same design is solved four ways across the two weeks — each route should arrive at the same answer.
Size the main by reading off the manufacturer's flow / pressure-drop charts for PE pipe.
Use the Mears hand-disc calculator to determine the diameter for the required flow and drop.
Adapt the IGEM/TD/3 spreadsheet backbone to solve for diameter — enter a trial pipe size and read off the pressure drop.
⬇ Download Excel backboneSolve the same supply using the Brackno network-analysis tool.
Launch tool — link comingBrackno delivers practical gas network training and consultancy across all pressure regimes.
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