- 6 -
Outlet
Inlet
Fig. 6
N2.4 Single shown.
It must be ensured that the water storage capacity is sufficient to meet the flow rates
required by the pump and any other water using fittings and appliances, which may be
operated simultaneously.
As a rule of thumb: assuming a cold water temperature of 10°C and a hot water
temperature of 65°C.
A 6-minute shower using 10 litres/min will consume 40 litres of hot water and 20 litres
of cold. This means the total quantity of water used from the cold water storage tank
will be 60 litres (40 + 20).
A 10-minute shower using 15 litres/min will consume 100 litres of hot water and 50
litres of cold. This means the total quantity of water used from the cold water storage
tank will be 150 litres (100 + 50).
On installations where there are high flow requirements e.g. multiple showers or body
jets.
A 10-minute shower using 45 litres/min will consume 300 litres of hot water and 150
litres of cold. This means the total quantity of water used from the cold water storage
tank will be 450 litres (300 + 150).
The pipework feeds to the storage tank should be of adequate size to ensure
replenishment rate of tanks is sufficient to meet the needs of the pump.
Care should be taken in the design of pipework runs, to minimize the risk of airlocks.
To prevent loss of water pressure through pipework use 28 mm suction pipework to the
pump.
Any bend requirements should be achieved by hand drawing the tube or by use of the
appropriate bend fittings. All pipework should be securely clipped.
Isolating valves (not supplied) should be fitted on the suction and delivery pipework to
enable easy isolation and access to the pump.
The 1 " inline strainer as supplied should be fitted in the suction line to the pump
between the isolating valve and the pump. This will eliminate the risk of debris or scale
entering the pump.
Pipework Connections (Cold)
The pump must be supplied with a dedicated feed direct from the cold water
storage tank.
Ensure the pipework size from the cold water storage tank to the pump is of adequate
size and a minimum of 28 mm.
The supply must be air free and connections of the feed pipe to the tank should be via
a tank connector, positioned at a slightly lower level (25 mm minimum) than the feed pipe
to the hot water cylinder.
