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INTRODUCTION
The fittings covered by these instructions should be installed in accord
-
ance with the Water Regulations published in 1999*.
Ideal Standard strongly recommends that these fittings are installed by
a professional fitter.
*A guide to the Water Supply (Water Fittings) Regulations 1999 and the Water Byelaws 2000, Scotland is published
by WRAS (Water Regulations Advisory Scheme) Unit 13, Willow Road, Pen-y-Fan Industrial Estate, Crumlin, Gwent,
NP11 4EG.
ISBN 0-9539708-0-9
WATER REGULATIONS
Hot and cold water supply pressures must be reasonably balanced and from a common source - both
from storage or both from a supply pipe. (IRN 101). The mixers will function within specification on
unequal pressures up to a ratio of 5 : 1, but it is not recommended that the cold supply be connected
to the rising main and hot to the tank fed supply as the pressure differential is likely to exceed the 5:1
ratio.
(See table 1)
The minimum pressure for correct operation is 1.0 bar. Pressure head is measured
as the vertical distance between the bottom of the cold water storage tank which feeds the hot water
system and the highest point on the shower spray plate. When installing with a shower pump the use of
a secondary tapping from the cylinder is highly recommended.
The picture below shows the various methods of connecting the hot water pipe to the cylinder - the most
preferred on the left and the least preferred on the right.
The fitting should be so installed as to be readily accessible for examination, repair, replacement or
operation. (IRN 111).
The temperature of the hot water must not exceed 85ºC but the installer’s attention is drawn to code
of practice BS 6700 which recommends that stored hot water should normally never exceed 65ºC. For
correct operation of the valve, a minimum of 55ºC is required.
most preferred solution
least preferred solution
Essex flange 22mm
Surrey flange
22mm outlet
From vertical
expansion pipe
22mm pipework
Preferred arrangements for cylinder tapping
From underside of
expansion pipe off-set
at 60º 22mm pipe
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Note:
If water supply is fed by gravity then supply pressures should be verified to ensure the
conditions of use are appropriate for the valve.