Davey Water Products HS Serie Instrucciones Para La Instalación Y Operación página 8

Driven point flow capacities vary considerably. Check with the supplier
to ensure the pump and spear point are correctly matched.
Where to use Check Valves and Foot
Valves
Installations with a suction lift over 3ft require a good quality foot valve to
avoid loss of prime. In this case, the check valve inside the pump should
be removed or overridden (see below).
Inlet Check Valve Removal / Override
Pressure Warning
IMPORTANT: For Automatic Pressure
Pumps installed with a mains pressure
hot water system. Hot water system
installation must comply with all local
plumbing regulations.
A good quality non-return valve must be installed in the pressure
pump outlet pipework before the hot water service. Failure to
install this non-return valve may result in pump damage. Such
damage is not covered by guarantee.
When used with a Float Valve
Where your pressure system is required to discharge through float valves filling tanks, the possibility of
excessive cycling may occur. This can be overcome by fitting a larger Davey Supercell pressure tank in
place of or in addition to the Supercell tank supplied.
Use of Existing Pressure Tanks
If your installation requires the removal of the
in-built check valve or the in-built check valve requires removal for servicing,
this can be achieved without difficulty. The in-built check valve is a cassette
design, which is screwed in through the suction inlet.
Removal of the check valve cassette is achieved by inserting any suitable tool
(eg. a pair of pliers or the handle from an adjusting spanner) into the inlet.
The check valve cassette has various ribs and recesses to allow a variety of
nonspecific tools to be used in the removal or insertion process.
If you already have a pressure tank in good condition, you can use
this tank to provide extra draw-off capacity (see Adjustable Cut-in
Screw Setting on page 4).
You should connect such tanks on a tee on the discharge pipework.
A check valve (NRV) should be installed on the discharge of the
Hydrascan ® CL before the tee to the existing tank - see diagrams.
NOTE: See Maintenance on page 10
for tank pre-charge pressures.
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