Instructions

Installation
The Caleffi 573 series backflow preventer with atmospheric vent must be installed in
accordance with the diagrams contained in this instruction manual taking into account all the
applicable Codes and Regulations.
Before installing a Caleffi 573 series backflow preventer, the system must be thoroughly
flushed to remove impurities or any debris which may have accumulated during installation.
Failure to remove dirt or debris may affect performance and the manufacturer’s guarantee.
The Caleffi 573 series backflow preventer must be installed preferably horizontally and
following the flow direction indicated by the arrow on the valve body.
The Caleffi 573 series backflow preventer must be installed with one isolating valve and a
strainer upstream and one isolating valve downstream.
The Caleffi 573 series backflow preventer must be installed in an accessible location to
facilitate testing and servicing.
The Caleffi 573 series backflow preventer must be installed with the vent port connected via
an air gap to a discharge line, in accordance with the plumbing code requirements and
keeping a minumum distance of 12” from the floor.
Do not install where the discharge can could cause damage.
If field testing is required by code, it must be installed in accordance with the relevant diagram
in this instruction manual.
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