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Old 09-02-2019, 09:49 AM   #43
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Originally Posted by grimstock View Post
The minimum bore of all pipes and fittings should be half an inch - 12mm approx. to give a constant gravity flow rate of 5 litres per minute. However pressure/flow rate will increase with severity of rainfall.
Precise control of suitable flow rate may be made better by a half inch ball valve, rather than one inch - but piping itself is sometimes better if using larger bore as self-bleeding may then occur more easily for most systems. The recommended diverter can shift over 500 litres rainwater/hour. So - yes, fitting half inch inlet valve to a slightly larger system piping is best for gravity feeding.

Last edited by grimstock; 09-02-2019 at 09:57 AM.
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