Section 45
of Water Supply Regulations 1961 Reprinted 1999
Section 45
Every cold water storage cistern of a capacity not exceeding one thousand gallons, and every flushing cistern, shall comply with the following requirements –
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(a)
it shall be fitted with an efficient warning pipe and with no other overflow pipe;
(b)
the internal diameter of the warning pipe shall be greater than the internal diameter of the inlet pipe and, in no case, less than three-quarters of an inch;
and
(c)
the overflowing level of the warning pipe shall be set –
(i)
below the top edge of the cistern at a distance of not less than twice the diameter of the warning pipe; and
(ii)
above the water-line at a distance of not less than one-inch or not less than the internal diameter of the warning pipe, which ever is the greater.
Requirements of storage cistern of more than one thousand gallons.