Davey HM Series Electric Pumps - Manual (Page 6)

Flow
Over 1m
0.5m
Min Foot Valve
(Not Supplied)
Flow
Check Valve
Figure A Figure B
Pipe Connections
For best performance use P.V.C. or polythene pipe at least the same diameter as
the pump’s inlet. Larger diameter pipe may be used to minimise resistance to flow
when pumping longer
distances.
Use unions at pipe
connections to enable
easy removal and
servicing. Use sufficient
tape to ensure airtight
seal and hand tighten only, do not screw connections all the way into suction port.
To prevent strain on pump thread always support heavy inlet and outlet pipes.
Lay suction pipe at a constant gradient to avoid air pockets which may reduce pump
efficiency.
Connection to your Water Source
ABOVE GROUND WATER SOURCES
Installations with flooded suction require a
gate valve so water supply can be turned off
for pump removal and servicing.
Install a one-way check valve in
the suction pipeline to avoid water
draining back past the pump while
not in operation and causing possible
pump damage.
BELOW GROUND WATER SOURCES
Whenever the installation position of the pump is higher than the lowest water level,
a foot valve fitted to the end of the suction pipe as illustrated in (A) below is required.
Ensure that the foot valve is at least 1 /
2
metre below minimum water level.
6 7
Spear Size Mesh Approx. Max. Capacity of Spear Point
1 1 /
4
” (32mm) 60 15 - 23 l/min or 200 - 300 gal/hr
1 1 /
2
” (38mm) 60 23 - 38 l/min or 300 - 500 gal/hr
2” (50mm) 60 38 - 75 l/min or 500 - 1000 gal/hr
NOTE: Be certain to select the spear point to suit the well conditions and
regulate the flow rate from the pump accordingly.
NOTE: DO NOT install the check valve at the pump or at the top of the
well. DO NOT run the pump without water.
SPEAR POINT INSTALLATIONS
When a HM is installed on a spear or well point a check valve fitted
immediately on top of the spear point itself, as shown in (B) above.
Dry-running protection
To avoid accidental loss of prime of the pump, we recommend protecting it with a
suitable device. Note: damage from dry-running is not covered by guarantee.
Connection of Mains Scheme or Town Water Supply to either Suction or
Discharge of Pumps
Most Water Supply Authorities have strict regulations regarding direct connection of
pumps to mains water supplies. In most cases an isolating tank is required between
mains supply and pump. Davey also recommend this method. Directly applied
mains pressure can exceed pump operating pressure and damage pump.
Davey Water Products Pty Ltd
can not accept responsibility
for loss or damage resulting
from incorrect or unauthorised
installations.
MAINS
WA
TE
R
NOTE: HM models require a foot valve or check valve to be installed in
the suction pipework in suction lift applications as appropriate.
MAINS
WA
TE
R
DO NOT USE THREAD SEALING COMPOUNDS, HEMP OR PIPE DOPE!
NOTE: Suction leaks are the largest
cause of poor pump performance
and are difficult to detect. Ensure all
connections are completely sealed using
thread tape only. DO NOT USE SEALING
COMPOUNDS OR PIPE DOPE.