Watts LF909 Pequeno Serie Manual De Instalación página 2

Installation Guidelines
• Install backflow preventers in high-visibility locations to
allow for immediate notice of telltale discharge or other
malfunction. This location should also facilitate testing and
servicing, and protect against freezing and vandalism.
• Do not install a backflow preventer in a pit or vault. Ensure
that all local codes and required safety provisions are met.
An air gap below the relief port must be maintained so as to
avoid flooding and submersion of the assembly, which may
lead to a cross-connection.
• Install a strainer ahead of the backflow preventer to protect
all internal components from unnecessary fouling.
! CAUTION
Do not install a strainer ahead of the backflow preventer on
seldom-used, emergency water lines (such as fire sprinkler
lines). The strainer mesh could potentially become clogged
with debris present in the water and cause water blockage
during an emergency.
• Consider using an air gap and a fabricated indirect waste line
to accommodate normal discharge and nuisance spitting.
Floor drains of the same size must be provided in case of
excessive discharge.
• Determine if a check valve is required ahead of the backflow
preventer. When a backflow preventer is installed for dead-
end service applications (such as boiler feed lines, cooling
tower makeup, or other equipment with periodic flow
requirements), discharge from the relief vent may occur due
to water supply pressure fluctuation during static no-flow
conditions. *See "Troubleshooting," before installation.
• Observe the direction of the flow arrows on the valve
assembly. The backflow preventer is designed so that the
critical level of the relief valve is positioned below the first
check. This unique feature allows the valve to be installed
either vertically or horizontally.
• Follow guidelines for the specific installation option selected,
that is, indoor, outside, or parallel. The installation procedure
must comply with all state and local codes.
• Before installation, thoroughly flush all pipelines to remove
any foreign matter.
• At the start-up of initial installation and after servicing, be
sure the downstream shutoff is closed. Slowly open the
upstream shutoff and allow the backflow preventer to fill
slowly. Bleed air at each test cock. When the backflow
preventer is filled, slowly open the downstream shutoff
and fill the water supply system. This is necessary to
avoid dislodging O-rings or causing damage to internal
components.
• Have the backflow preventer examined by a certified tester
at the time of installation to ascertain that the assembly is in
full working order and that it can be relied upon to protect
the safe drinking water as per applicable standards.
2
First
Check
LF909-QT-S-FS
Second
Check
Relief
Valve