
12
Pre-installation
Installation
PumpWise guidelines
General specification
Trouble shooting
PumpWise and warranty
Helpful
guidelines
Cold water supplies and storage
Recovery of cold storage
The typical recovery rate of a 1⁄2 inch high
pressure part II BS1212 ball valve is:
100 kPa (15PSI/1.0 bar) 0.97 galls/min 4.41
200 kPa (30PSI/2.0 bar) 1.34 galls/min 6.11
270 kPa (40PSI/2.7 bar) 1.58 galls/min 7.18
400 kPa (60PSI/4.0 bar) 1.94 galls/min 8.82
Aeration of pump and cylinder from a
cold water storage tank
This occurs when the incoming cold mains
ball valve is positioned above the cold
feeds to the cylinder and to the pump –
aerated water is drawn into the pump as
illustrated.
Figure 20: Aeration
Reposition
cold mains
ball valve
here
Vortex
Outlets
The bottom of
the cold tank
MUST BE
checked and
cleaned of debris
Fig 17 Aeration of pump
OLD STYLE DO NOT USED
Vortex
Reposition
cold mains
ball valve
here
Outlets to
pump
The bottom of the cold
tank MUST be checked
and cleaned of debris
Chronic aeration of the pump occurs when
this problem is combined with inadequate
storage capacity and/or when the volume of
water drawn by the pump and other services
exceeds the refill rate and creates a vortex
which draws air and possibly debris into the
pump.
Cold storage usable capacity
The usable capacity of cold storage is
easily calculated as the capacity of water
in the cold tank above the cold feeds to the
cylinder, the pump and other outlets –
see formula.
Formula for calculation on rectangular
tank:
Depth (15”) x width (23”) x length (36”)
= 12,420 cu inches
Volume cu inches (12,420) x 0.01639
= 203.56 litres
Volume litres (203.56) x 0.22
= 44.78 gallons.
Formula for calculation on circular tank:
Depth (15”) x radius (17”) x radius (17”)
x 3.142 (Pi)
= 13,621 cu inches
Volume cu inches (13,621) x 0.01639
= 223 litres
Volume litres (223) x 0.22
= 49 gallons.
Length
Width
Usable capacity
Depth
of
water
Outlets
The bottom of the cold
tank MUST BE checked
and cleaned of debris
Length
Width
Usable capacity
Depth
of
water
Outlets
The bottom of the cold
tank MUST be checked
and cleaned of debris
Fig 18 Cold storage
OLD STYLE DO NOT USED