Davey HP, HS & HM Pressure Systems with Presscontrol - Manual (Page 6)

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Installations with flooded suction require a gate or
isolating valve so water supply can be turned off for
pump removal and servicing.
For Automatic Pressure
Pumps Installed with a Mains
Pressure Hot Water System
To protect your system from damage caused
by back pressure from hot water systems. You
should always have installed on the hot water
inlet an approved non-return valve.
Connection of Mains Scheme or Town Water
Supply to either Suction or Discharge of Pumps &
Pressure Systems
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.
Abrasive Materials
The pumping of abrasive materials will
cause damage to the pressure system
which will then not be covered by the
guarantee.
NOTE: Always ensure hot
water systems are installed in compliance with manufacturers
recommendations and in accordance with all local regulations.
Pipe Connections
For best performance use P.V.C.
or polythene pipes at least the
same diameter as the pump’s
inlet and delivery outlet openings.
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. To prevent strain on pump threads
always support heavy inlet and outlet pipes. If there is
a likelihood the water supply may contain solid particles
such as pieces of plant or vegetable matter, a filter should
be installed before the pump to avoid blocking of water
ways. Lay suction pipe at a constant gradient to avoid air
pockets which may reduce pump efficiency.
Extra Draw-off Capacity
The “Presscontrol” has an inbuilt accumulator which will accommodate small
leaks. In some applications it may be appropriate to install additional accumulator
(Supercell pressure tank) capacity. These applications includes:
• Long suction lines (see Suction Lines / Lift)
• Low flow appliances connected to the pump, such as evaporative air
conditioners, slow filling toilet cisterns.
Any additional accumulators can be installed downstream of the controller (ie.
between the controller and the first outlet).
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 THREAD SEALING COMPOUNDS, HEMP OR PIPE DOPE!
Do not use pipe thread sealing compounds on any part of this pump. ONLY
use Teflon sealing tape.