Gas Pipe Sizer
Natural gas, copper tube. Checks each pipe section against the BS 6891 discharge table and totals the pressure drop from meter to appliance.
Index Run Result
Total pressure drop (index run)
0.64 mbar of 1.0 allowed
Index run sections
Pipe size
Length (m)
Load (kW net)
Fittings
Elbows (+0.5 m)
Tees (+0.5 m)
90° bends (+0.3 m)
Eff. length
5.0 m
Flow
3.672 m³/h
Capacity
6.767 m³/h
Drop
0.295 mbar
Pipe size
Length (m)
Load (kW net)
Fittings
Elbows (+0.5 m)
Tees (+0.5 m)
90° bends (+0.3 m)
Eff. length
8.0 m
Flow
2.950 m³/h
Capacity
5.000 m³/h
Drop
0.348 mbar
Pipe size
Length (m)
Load (kW net)
Fittings
Elbows (+0.5 m)
Tees (+0.5 m)
90° bends (+0.3 m)
Eff. length
6.0 m
Flow
0.722 m³/h
Capacity
1.900 m³/h
Drop
0.144 mbar
Pressure drop per section is estimated as (flow / table capacity)² × 1 mbar. This is a training and checking aid: always confirm final sizing to BS 6891 and the appliance manufacturer's instructions.
View our gas coursesFor training and reference only. Check every result against the current standard, the manufacturer's instructions and your own readings. The engineer carrying out the work is responsible for the result.
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