Zip Aquapoint III AP3/30 Installation Instructions Manual page 3

Safety relief valve connections should not be used for any other purpose and no
valve should be fitted between the expansion relief valve and the storage cylinder.
An isolating valve must be fitted to the cold water supply to the inlet manifold.
The Zip Aquapoint is designed for use with a supply pressure up to 12 bar. For
supply pressures exceeding 12 bar an additional pressure reducing valve must
be fitted in the cold water supply to the unit.
Secondary Circulation
The Zip Aquapoint is not recommended for use with secondary circulation
systems.
Discharge
The expansion relief and temperature and pressure relief valves should drain via
a tundish which should be installed in a visible location and away from any
electrical devices.
The discharge pipe from the tundish should terminate in a safe place where
there is no risk to persons in the vicinity of the discharge, be of metal and:
a) Be at least one pipe size larger than the nominal outlet size of the safety
device unless its total equivalent hydraulic resistance exceeds that of a
straight pipe 9m long. 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 18 and 27m at least 3 sizes
larger, and so on. Bends must be taken into account in calculating the
flow resistance. See diagram of typical discharge pipe arrangement and
table for sizing copper discharge pipe.
b) Have a vertical section of pipe at least 300mm long, below the tundish
before any elbows or bends in the pipework.
c) Be installed with a continuous fall.
d) Have discharges visible at both the tundish and the final point of discharge
but where this is not possible or it is practically difficult there
should be clear visibility at one or other of these locations. Examples of
acceptable discharge arrangements are:
1. Ideally below a fixed grating and above the water seal in a trapped gully.
2. Downward discharges at a low level: i.e. up to 100mm above external
surfaces such as car parks, hard standings, grassed areas etc. 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.
3. Discharges at high level: e.g. into metal hopper and metal down-pipe
with the end of the discharge pipe clearly visible (tundish visible or not)
or onto a roof capable of withstanding high temperature discharges of
5 AP3/30, AP3/50, AP3/80, AP3/100 Installation Instructions
water and 3m from any plastic guttering system that would collect
such discharges (tundish visible).
4. Where a single pipe serves a number of discharges, such as in blocks
of flats, the number served should be limited to not more than 6 systems
so that any installation can be traced reasonably easily. The single
common discharge pipe should be at least one pipe size larger than the
largest individual discharge pipe to be connected. If unvented hot water
storage systems are installed where discharges from safety devices may
notbe apparent e.g. in dwellings occupied by blind, infirm or disabled
people, consideration should be given to the installation of an electronically
operated device to warn when discharge takes place.
Note: The discharge will consist of scalding water and steam. Asphalt, roofing
felt and non-metallic rainwater goods may be damaged by such discharges.
Typical discharge pipe arrangement
Sizing of copper discharge pipe 'D2' for common temperature
relief valve outlet sizes
Valve Minimum size Minimum size of
outlet of discharge discharge pipe D2
size pipe D1 from tundish
22mm
1 /
G 15mm 28mm
2
35mm
28mm
3 /
G 22mm 35mm
4
42mm
35mm
G 1 28mm 42mm
54mm
AP3/30, AP3/50, AP3/80, AP3/100 Installation Instructions
Maximum resistance Resistance
allowed, expressed as a created by
length of straight pipe each elbow
( i.e. no elbows or bends) or bend
up to 9m 0.8m
up to 18m 1.0m
up to 27m 1.4m
up to 9m 1.0m
up to 18m 1.4m
up to 27m 1.7m
up to 9m 1.4m
up to 18m 1.7m
up to 27m 2.3m
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