discharge pipes given in BBA Information No 33 :
1989 are generally recommended.
(5) The system is installed in locations similar to
those for storage cylinders used in a conventional
vented system or in other locations advantageous
to the building designer (see Table 1 for load
weight of the system when ‘full’). It is important to
ensure there is adequate clearance for the removal
of the immersion heater and the corrosion
protection anode (see Table 1).
(6) Electrical wiring must be carried out in
accordance with the IEE Wiring Regulations. The
immersion heater circuit must be protected by a
suitably-rated fuse and an isolating switch with
double pole disconnection.
(7) It is essential that the motorised valve
supplied with the system is installed and is not
substituted by any other motorised valve which
may exist and be in service at the site of
installation, eg a motorised valve installed in a
central heating circuit.
17 Procedure
Summary of installation procedure
17.1 The storage cylinder is located in position
(see the
Kwikot Technical Information and Installers
Instructions
) and the plumbing connections made to
the inlet and outlet pipes in the same manner as for
a conventional storage cylinder, except that the
water supply pipe is taken directly from the mains
or other suitable potable supply, via the line
strainer and cold water control valves (ensuring the
arrow markings on the components are pointing
downstream) to the cold water inlet of the storage
cylinder (see Figure 2). Where balanced pressures
are required, the cold water draw-off is connected
as shown in Figure 2, using components supplied
by the Certificate holder.
17.2 The discharge pipe is connected to and
from the tundish to a safe and visible termination
point [see sections 16(3) and (4) of this Detail
sheet]. The air gap at the tundish must remain
clear.
18 Commissioning
18.1 The system is filled with water and checked
for watertightness. The expansion vessel is
checked against the manufacturer’s stated
specification (3.5 bar). The expansion valve and
the combined temperature and pressure relief valve
are manually operated to ensure water discharge
from the valves runs freely through the tundish to the
termination point. The valves are visually checked
to ensure that they re-seat satisfactorily. Heat is
applied to the system and is allowed to reach
normal working temperature. The operation of the
thermostat is checked and an examination carried
out to ensure that no water has discharged from the
expansion valve or the combined temperature and
pressure relief valve during the heat-up.
18.2 On completion of the commissioning
process the
competent person
completes the label
attached to the system, stating that the installation
complies with the Certificate (see section 3).
Technical Investigations
The following is a summary of the technical
investigations carried out on the Kwikot Indirect
Unvented Hot Water Storage System.
19 Tests and investigations
19.1 Tests were carried out in accordance with
MOAT No 38 : 1986 to determine:
• capacity of storage cylinder
• dimensional accuracy
• mean supply temperature
• outlet flow rate at various supply flow rates
and pressures
• time taken to heat to 60°C
• re-heat time to 60°C
• standing energy loss (adequacy of insulation)
• watertightness
• resistance of the storage cylinder and expansion
vessel to an internal hydrostatic pressure of 1.5
times the design pressure = 7.5 bar
• resistance to partial vacuum of 0.1 bar absolute
•
flow capacity of the tundish and discharge
pipework.
19.2 Tests were carried out to confirm satisfactory
operation of the following components when fitted
in a system:
• cold water control valves, to include:
– pressure control valve
– expansion valve
– check valve
• combined temperature and pressure relief valve
•
immersion heater thermostat and non-self-resetting
thermal
cut-out
• line strainer
• motorised valve.
19.3 An examination was made of existing data
in relation to the performance requirements of the
relevant British Standards, to determine the
suitability and performance of:
• cold water control valves, to include:
– pressure control valve to BS 6283-4 : 1991
– check valve to BS 6282-1 : 1982
– expansion valve to BS 6283-1 : 1991
• combined temperature and pressure relief valve
to BS 6283-3 : 1991
• line strainer
• immersion heater to BS EN 60335-2.73 : 2003
7
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