sizing of gas pipe for domestic installation

Forum about flow calculators available on pipeflowcalculations.com and how to find solution for your fluid flow problem.
Post Reply
sparky
Posts: 2
Joined: Sun Jan 08, 2012 10:04 am

sizing of gas pipe for domestic installation

Post by sparky »

Can anyone tell me how to determine pipe diameter for a domestic install?

Maximum demand is 390MJ/hr

Length at furthest point from supply is approx 70 Metres.

I have been unable to find the supply pressure for South Australia.
PipeFlowCalcs
Posts: 57
Joined: Sat Sep 17, 2011 8:50 am

Re: sizing of gas pipe for domestic installation

Post by PipeFlowCalcs »

Is it natural gas? Pressure is required for calculation.
Pipe flow calculations - free fluid flow calculators
sparky
Posts: 2
Joined: Sun Jan 08, 2012 10:04 am

Re: sizing of gas pipe for domestic installation

Post by sparky »

Yep. It's natural gas.
PipeFlowCalcs
Posts: 57
Joined: Sat Sep 17, 2011 8:50 am

Re: sizing of gas pipe for domestic installation

Post by PipeFlowCalcs »

390 MJ/h = 108 kW = 11 m3/h (depending on gas quality).
If gauge pressure is 22 mbar, velocity 5 m/s internal pipe diameter should be 28.36 mm, which is 1" pipe.
Pressure drop for 70 m pipe is 7 mbar which about 30% of available gauge pressure and I think it is ok too, but with 5/4" pipe you will be on safe side 100%.
Use pressure drop calculator.

Here is the report:

Pipe pressure drop calculator

1. volume flow rate (q):
q : 11 m3/h

2. weight flow rate (w):
w : 8.8 kg/h

3. pipe length (L):
L : 70 m

4. pipe diameter (D):
D : 28.5 mm

5. pipe roughness (kr):
kr : 0.1 mm

6. density (ρ):
ρ : 0.8 kg/m3

7. kinematic viscosity (ν):
ν : 13 mm2/s

8. dynamic viscosity (μ):
μ : 10.4E-006 Pas

9. K factor - minor lossed coefficient (K ):
K : 0.0

10. velocity (V):
V : 4.7897277 m/s

11. cross section area (A):
A : 637.9397 mm2

12. friction coefficient (f):
f : 0.031255998

13. Reynolds number (Re):
Re : 10500.558

14. boundary layer (δ):
δ : 0.54144156 mm

15. pressure on the pipe start (p1):
p1 : 1.033 bar

16. pressure on the pipe end (p2):
p2 : 1.0259552 bar

17. pressure drop (p1-p2):
p1-p2 : 7.0447927 mbar
Pipe flow calculations - free fluid flow calculators
Post Reply