Connection To Services; Secondary Return; Discharge Pipework - Ariston ST 100 ProTech Instructions For Installation, Servicing And Use

3.10 c
onnection to
3.11 s r
econDAry eturn
3.12 D p
iscHArGe ipework
14
s
It is recommended that a 22mm pipe run should supply the outlets
ervices
throughout the building, especially to baths and showers. Short runs of
15mm pipe may be used to connect basins and sinks.
On floor-standing models a secondary return may be fitted (consult the label
on the face of the unit for the correct location). A non-return valve (not
supplied) must be fitted to prevent back flow and a bronze pump will be
needed in conjunction with a pipe thermostat and timer to circulate the hot
water (both not supplied).
n : an extra expansion vessel may be required where the additional
ote
volume of the secondary return exceeds the capacity of the expansion
vessel supplied.
n !
ote
t
He sAFety relieF vAlves Must not Be useD For Any otHer purpose
1) Discharge pipes from the temperature & pressure relief and expansion
relief valve may be joined together.
2) The tundish must be vertical and fitted within 600mm of the temperature
& pressure relief valve and must be located with the cylinder but away
from any electrical devices. The tundish must also be in a position visible
to the occupants, and positioned away from any electrical devices. The
discharge pipe from the tundish should of metal and terminate in a safe
place where there is no risk to persons in the vicinity of the discharge.
3) The pipe diameter must be at least one pipe size larger than the nominal
outlet size of the safety device unless it's total equivalent hydraulic
resistance exceeds that of a straight pipe 9m long.
i.e. Discharge pipes between 9m and 18m equivalent resistance length
should be at least 2 sizes larger than the nominal outlet size of the safety
device. Between 18m and 27m at least 3 larger, and so on.
Bends must be taken into account in calculating the flow resistance.
See F
4) The discharge pipe must have a vertical section of pipe at least 300mm
in length below the tundish, before any elbows or bends in the pipework.
5) The discharge pipe must be installed with a continuous fall and should be
at least one pipe diameter clear of the wall where it terminates.
6) The discharge should be visible at both the tundish and the final point of
discharge, but where this is not possible or practically difficult; there
should be clear visibility at one or other of these locations. Examples of
acceptance are:
. 3.11 and t 2.
iG ABle
i) Ideally below a fixed grating and above the water seal in a trapped
gully.
ii) Downward discharges at a low level; i.e. up to 100mm above
external surfaces such as car parks, hard standings, grassed
areas etc. These are acceptable providing that where children
may play or otherwise come into contact with discharges, a wire
cage or similar guard is positioned to prevent contact, whilst
maintaining visibility.
iii) Discharges at high level; Onto a roof capable of withstanding high
temperature discharges of water 3m from any plastic guttering
systems that would collect such a discharge (tundish visible).
iv) Where a single pipe serves a number of discharges, such as in
blocks of flats, i.e. into a metal hopper and metal down pipe with
the end of the discharge pipe clearly visible (tundish visible or
not). the number served should be limited to not more than 6
systems so that any installation can be traced reasonably easily.