Stuart Turner Techfo TP 50T - Manual (Page 7)

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Cont ...
2.31 Non-Preferred Pump Location: The pump must be located with at least
0.5 metre flooded suction at all times.
If it is not possible to locate the pump in the preferred area due to site limitations
and it is necessary to position the unit in the loft, or in a position above the
secondary tapping that feeds the pump, then there is an increased risk of air
locks. This risk must be eliminated.
The following method will help to overcome the problem:
In this application only use an Essex or Techflow side entry flange, then fit a “U”
bend or downward loop in the supply pipe to the pump of 350 mm depth before
rising to the pump should ensure the cylinder vents its air up the
expansion pipe, not up the pump feed (Fig. 5 & Fig. 6).
Fig. 5 (Twin Pump)
Fig. 6 (Single Pump)
Max. inlet head
10
m
Min. inlet head
0.5
m
Max. inlet head
10
m
Min. inlet head
0.5
m
hot water
services hot water
services
least preferred area least preferred area
200
mm
min
200
mm
min
350
mm
min 350
mm
min
Fig. 4
(b) Factory installed
G ¾ secondary
tapping with
22 mm pipework to
pump (a) Site installed
22 mm Techflange
with 22 mm
pipework to pump (c) Site installed
G 1 Techflange
with 22 mm
pipework to
pump