Quizzes & Puzzles8 mins ago
Garden hose flow rate
11 Answers
I need to replace my 1/2 inch 50m watering hose on my allotment. The stand pipe has a 1/2 inch tap. The water has to flow a foot uphill. Would I get an increased flow rate if I used a hose wider than the standard 1/2 inch? (I am allowed 30 min water per day. Some people have enough pressure to use sprinklers ++. At present the flow from my aged hose is feeble.)
Many thanks.
Many thanks.
Answers
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For more on marking an answer as the "Best Answer", please visit our FAQ.Thanks for the suggestiions. I'm wondering if the 1/2inch tap would be the limiting factor and that investing in 3/4 or 1 inch width hose wouldn't make any difference. I do know that the 50m length affects the pressure I will get out, but I can't do anything about that.
Perhaps I need to learn about the physics of flow through a pipe.
Perhaps I need to learn about the physics of flow through a pipe.
I agree with Albags that one foot of height makes no difference.
But I do not agree in relation in the pipe diameter. The physics of it would indicate that the flow of water from the hose end depend upon:
the dynamic pressure at the standpipe end (when water is flowing)
the length of the hose
the diameter of the hosepipe
The trouble is that it is going to be difficult to calculate the impact of any difference and other factors come into play. For instance, the dynamic pressure at the standpipe depends on the length of the feedpipe and its diameter (the pipe in the ground - and you can't control that).
As an aside, if you want to maximise the amount of water being extracted in your precious 30 minutes (irrespective of what diameter hose you finally choose), try to water at a time when FEW OTHERS are also watering - the dynamic water pressure at your standpipe will be at its highest.
But I do not agree in relation in the pipe diameter. The physics of it would indicate that the flow of water from the hose end depend upon:
the dynamic pressure at the standpipe end (when water is flowing)
the length of the hose
the diameter of the hosepipe
The trouble is that it is going to be difficult to calculate the impact of any difference and other factors come into play. For instance, the dynamic pressure at the standpipe depends on the length of the feedpipe and its diameter (the pipe in the ground - and you can't control that).
As an aside, if you want to maximise the amount of water being extracted in your precious 30 minutes (irrespective of what diameter hose you finally choose), try to water at a time when FEW OTHERS are also watering - the dynamic water pressure at your standpipe will be at its highest.
The pressure available to you is very important, as others have pointed out, and you have no control over that but buildersmate's advice is precisely correct. Since the length you require is in effect dictated to you, the only factor you have control over is the diameter of the hose. Yes, a larger diameter would reduce the resistance to flow through the hose and the more rigid and smooth on the inside it is then the less resistance you will suffer. Fifty metres of hose is quite a substatial length and in actual fact, if you were to conduct a test, there would come a point whereby continually lengthening the run of hose would result in a mere trickle even on the horizontal with the tap fully open - but currently a 30cm rise probably does not have the biggest effect although (in your test) you could cut the flow completely for a good while simply by raising the end of the hose 30cm. My advice would be to get a larger diameter hose and try to make sure it is unlikely to kink/collapse (thicker walled is better) and is the smoothest one on the inside on offer. Then look after your hose, coiling it carefully for storage and fastidiously avoid kinking or squashing in any way.
Many thanks everyone.
Will look for a smooth inner-walled garden hose. If I can find an affordable wider-bored hose I will go for that. To be honest I suspect anything will be better than my aged and cheap garden hose. Hopefully either way I can spend less time watering in these very dry spells. Perhaps it might even rain.
Will look for a smooth inner-walled garden hose. If I can find an affordable wider-bored hose I will go for that. To be honest I suspect anything will be better than my aged and cheap garden hose. Hopefully either way I can spend less time watering in these very dry spells. Perhaps it might even rain.