Davey 165D DEEP WELL PRESSURE PUMPS & SYSTEMS - Manual (Page 4)

- 4 - - 9 -
Installation Procedure
The Deep Well Injector Kit comprises a bronze injector and foot valve
assembly which is attached to the end of polythene piping and lowered
into the water. Deep well injector kits include all appropriate fittings for
connection of pipes to pump.
Suction Piping for use on Deep Well Injectors
All Deep Well Injectors require two pipes to be connected between the pump and
the injector, the larger being the suction pipe and the smaller the pressure pipe.
Pipe sizes are according to the table below (except where special sizes may
be specified for a particular installation - consult your Davey Dealer or Davey
Customer Service Centre).
Deep Well Injector Kit No. Suction and Pressure Pipe Sizes
22469, 22470, 22471, 22472.
22473, 22474, 22475
1 1 /
2
”and 1 1 /
4
”
22570, 22571, 22572, 22573 2” and 1 1 /
2
”
Polythene piping is recommended. Select the grade of pipe which has a pressure
rating equal to the pump max. pressure and the depth to water. Normally rural
class B polypipe is ample. If higher rating pipe is required, consult your Davey
dealer.
Plumbing of Deep Well Injectors
A minimum submergence of 3m (10 ft.) is required for the injector and foot valve
assembly for correct operation.
When water is pumped out from a borehole it is common for the water level in
the bore to drop. However, there is usually a point at which the bore water level
remains static or constant for a given maximum flow from the bore. This new level
is known as the ‘draw down level’ of the bore. It is necessary to establish this
draw down level and the output capacity of the bore at this level before installing a
pump on the bore.
Once the pump has been installed on the bore, it is necessary to regulate the
flow from the pump to ensure it does not exceed the maximum capacity of the
bore at the draw down level. Refer Automatic Demand Response (ADR) Set Up
Instructions.
The minimum submergence of the injector and foot valve assembly of 3m (10 ft) means
the length of piping required from the top of the bore to injector assembly is equal
to the draw down level plus 3m (10 ft). Furthermore, ensure that at least a 2m (6 ft)
clearance exists between the injector assembly and the bottom of the bore.
With the adjustment screw on the ADR valve adjusted fully out, run the pump
until the bore is pumped down to its ‘draw down’ level, whilst the pump outlet is
allowing water to discharge unimpeded.
Maintain the pump pressure at this level using gate valve.
Screw regulating valve adjustment screw in until pressure starts to rise. Open
gate valve a little further, then readjust regulating valve to maintain required
minimum pressure on gauge When gate valve is fully open and regulating valve
is maintaining operating pressure, adjustment is complete. Your pump will now
resist operating in a loss of prime condition, but also optimise it’s performance at
higher pressures. If pump is allowed to operate below the minimum on the table
below, cavitation will occur which causes excessive pump wear, or prime may be
lost.
Deep Well Minimum Operating Max Shut-off
Injector Pressure Pressure
Model kPa psi kPa psi
22469 200 29 550 80
22470 195 28 645 93
22471 220 32 575 83
22472 235 34 660 96
22473 160 23 620 90
22474 240 35 635 92
22475 240 35 750 109
22570 230 33 650 94
22571 170 25 590 86
22572 230 33 630 91
22573 240 35 540 78
Once set there should be no need to alter the setting of the ADR valve, unless
there is a major change with the installation.
To Check for Correct Automatic Pressure System
Operation
1. Close gate valve at pump outlet, allowing pump to run and build up pressure
until it switches off at cut-out setting of pressure switch (factory setting of
350kPa).
2. Open gate valve at pump outlet to allow water to discharge to an outlet point.
Pump will automatically switch on at cut-in setting of pressure switch (factory
setting of 210kPa).
Always operate the pump at or above the minimum operating pressure. Failure to do
so will result in pump damage not covered by guarantee.