Table of Contents
Advertisement
10.3.1
EXPANSION VESSEL SIZING
The following information is based on an inlet pressure of 3.5 bar. If a different inlet pressure is to be used, please
consult BS6700.
V V = S V * e
0.45
Where:
V V
=
Vessel Volume
S V
=
System Volume
e
=
Coefficient of Expansion
Stored Temp.
Stored Temp.
TABLE 10.1
10.4
DE-STRATIFICATION
If the hot water system does not include a constantly circulated building return, it is recommended that a de-
stratification pump is fitted, between the building flow connection and the drain connection of the storage vessel, to
ensure an even temperature distribution throughout the stored water. De-stratification pump kits are available as
ancillary items; please contact Lochinvar Limited for details.
10.5
CIRCULATING PUMPS
In order to ensure the correct flow rates through the water heater, the unit requires a bronze glanded pump sized to
overcome the resistance of the heat exchanger and a primary pipework loop. The primary loop should be no longer
than 14 metres plus the following fittings:
6 x 90 Elbows
2 x Unions
2 x Full bore lever ball valves
2 x Tee fittings (cold feed & building return)
For longer distances or a greater number of fittings, the pump may have to be resized.
The specification of this type of pump ensures that the bronze body and associated parts in contact with water are
suitable for potable use. A "glanded" construction is required to ensure that any scale in the system does not build up
within the pump and cause a resistance that can lead to a loss of water flow. Glandless (canned rotor) pumps are not
recommended by Lochinvar Limited due to the fact that in hard water areas, scale can build up within the rotor and
failure can occur, not only of the pump but also the heater itself. The warranty will be void if a failure of the heat
exchanger occurs due to a "glandless" pump.
EKW45CE
EKW60CE
EKW85CE
EKW115CE
EKW145CE
EKW175CE
EKW205CE
EKW235CE
Primary circulating pumps are available as ancillary items; please contact Lochinvar Limited for details.
(See Table 10.1)
30
35
C
e
0.005
0.006
0.008
65
70
C
e
0.020
0.023
0.026
COEFFICIENT OF EXPANSION OF WATER AT 3.5 BAR INLET PRESSURE
Model
Differential (K)
10.0
10.0
10.0
10.0
10.0
12.2
12.2
13.3
TABLE 10.2
40
45
50
55
0.010
0.012
0.015
75
80
82
85
0.030
0.031
0.033
FLOW
Total System Pressure
(Litre/sec)
Loss (Meter- H
0.98
7.32
1.17
6.71
1.80
6.07
2.82
8.51
3.19
7.93
3.30
7.90
4.00
9.80
4.20
9.40
SYSTEM HEAD LOSS
60
0.017
90
0.037
0)
2
26
Hide quick links:
Advertisement
Table of Contents
