12
13
Water starvation protection
In systems where it is absolutely not
possible to increase the usable cold water
storage capacity to meet the increased
demand of a pumped system; a water
starvation protection unit (WSP) may be
considered (See fig 11).
The WSP is a Salamander level switch which
must be positioned 102mm higher than the
highest outlet from the cold water storage
cistern. When the water level drops too far
the WSP will switch off the pump until the
cold water storage level is recovered.
Combi boilers and water heaters
As these appliances are invariably supplied directly from the cold mains – they are not
suitable for this range of pumps, unless pumping from a cold water storage cistern
via a universal pump.
Horizontal cylinders
As horizontal (Torpedo) cylinders are problematic for boosted systems consult PumpWise
on 0191 516 2002 for guidance and correct use of an approved top entry flange.
S flange
Complete with compression pump outlet and the open vent connections. Also supplied with
an adaptor to connect to 1” male and female top entry cylinders. (See fig 13).
Helpful guidelines
Cold water supplies and storage Recovery of cold storage
Ensure that there is sufficient water recovery to cover the water usage by the appliance.
Aeration of pump and cylinder from a cold water storage cistern
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.
Chronic aeration of the pump occurs when
this problem is combined with inadequate
storage capacity and/or when the volume
of water is 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
cistern above the cold feeds to the cylinder, the pump and other outlets – see formula.
Formula for calculation on rectangular cistern:
Water above inlet (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
Outlets
to pump
Vortex
Reposition
cold mains
ball valve here
The bottom
of the cold
tank must
be checked
& cleared
of debris
Widt
h
Length
Depth
of water
Useable capacity
102mm
Outlets
Water starvation
protection unit
Cold water storage
Inlet
Min 600mm
Air vents,
both hot
and cold
Outlet
Outlet
Vent and
other services
No Stop Essex Flange
MUST be used with
an anti-gravity loop at
least 200mm in depth
MAX
60°C
MAX
60°C
Inlet
To vent
S flange
To pump
HOT WATER
CYLINDER
Figure 9: Aeration
Figure 10: Water capacity calculations
Figure 11: Water starvation protection
unit (WSP)
Figure 12: Anti-gravity loop (AGL) - pumps
above the hot water cylinder
Figure 13: S flange
The best method is the no stop
Essex flange with an anti-gravity
loop at least 400mm in depth.
Summary of Contents for CT FORCE series
Page 16: ...28 29 Notes Notes...
