Method Of Operation - Honeywell BA 299 I Einbauanleitung

1. Introduction
Installation Guidelines Install according to local regulations and codes of practice and
in accordance with installation instructions.
The installation location must be protected against frost and
be easily accessible.
Scope of Application BA 299 I backflow preventers are for industrial purposes and
are available with threaded connections in sizes
Typ BA 299 I backflow preventers are suitable for protecting
potable water systems against back pressure and back
syphonage. Protection is provided for liquids up to and including
class 4 risk to DIN 1988 part 4 and DIN pr EN 1717 (at present
provisional). This corresponds to construction type 2 as specified
in DIN 1988, Part 4. They can be used for industrial , commercial
or residential applications within the limits of their specification.
Risk category 1 Water for human consumption which is taken direct from a
potable water supply
Risk category 2 Liquids which present no health risk to humans.
Liquids which are suitable for human consumption, including a
potable water system where a change in taste, smell, colour
or temperature (heating or cooling) may occur.
Risk category 3 Liquids which, because of the presence of one or more
poisonous substances, present a health risk to humans.
Risk category 4 Liquids which, because of the presence of one or more very
poisonous substances or which contain one or more
radioactive, mutagenic or carcinogenic substances, present a
health risk to humans.
Risk category 5 Liquids which present a health risk to humans because of the
presence of bacterial substances.
The higher the classification, the greater the risk potential. DIN pr EN 1717 defines acceptable
safety protection devices for every risk category. BA 299 I backflow preventers are permitted
without restriction for all risk categories up to and including risk category 4. A continuous
bacterial risk must not be present.
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GB
1 / " to 2".
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2. Method of Operation

Type BA backflow preventers are divided into three zones. The
pressure in Zone 1 is higher than in Zone 2, which in turn is
higher than in Zone 3. A discharge valve is connected to Zone
2 and this opens at the latest when the differential pressure
between Zones 1 and 2 has fallen to 0.14 bar. Water from
Zone 2 then discharges to atmosphere. The risk of back
pressure or back syphonage into the water supply network is
thereby prevented. The water supply pipe is interrupted and
the potable water supply network is protected.
Zone 1
Inlet non-return check
valve
Flow position Shutoff position
as long as the differential The discharge valve opens
pressure between the inlet to atmosphere if the
and middle chambers is differential pressure
greater than 0.14bar, the between the inlet and the
discharge valve remains middle chambers falls to
closed, even when water is 0.14 bar.
not being drawn off.
GB
Zone 2
Zone 3
Outlet non-return
check valve
Discharge valve
Threefold protection
Two non-return check
valves and a discharge
valve divide the sytem into
three chambers. The
discharge valve opens
even if both check valves
do not fully seal.
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