Honeywell R295HP-F Einbauanleitung Seite 5

1. Installation
It is necessary during installation to comply with
local requirements, to follow codes of good
practice and to follow the installation instructions.
The installation location should be protected
against frost and be easily accessible.
1.1 Installation Guidelines
• Flush connecting pipework thoroughly before
installation
• Install the backflow preventer with good acces-
sibility and with flow in the correct direction.
• Install the backflow preventer only in horizontal
pipework and with the discharge tundish 6
downwards
• A clearance of A
min
backflow preventer for maintenance purposes
DN 65 80
A 170 200 240
min
• It is recommended that a Y-strainer 2
(e.g. FY 69) be fitted upstream to protect the
backflow preventer against coarse dirt.
• Fit shutoff valves 1 and 5 either side of the
backflow preventer.
• Install a small drain cock 7 upstream of the
backflow preventer
• Connect discharge pipe to discharge tundish 6
• If pressure shock is anticipated in the outlet
side of the backflow preventer, a pressure
shock damper or expansion vessel must be
fitted on the system down-stream of the
backflow preventer
2. Putting into operation
As supplied the hydraulically actuated
changeover valve is closed and the backflow
preventer is in the shutoff position.
Commissioning should be in the following sequence:
1. Slowly open shutoff valve 1
When reaching the minimum inlet pressure the
backflow preventer turns to flow position so
that the complete pipe unit is filled up to the
shut-off valve 5 .
2. Check flanged and pipework joints for seal.
3. Slowly open shutoff valve 5 . Fill and vent the
system.
4. After filling or when there's no more water
drawn from the system the differential
pressure transmitter switches over the
hydraulic actuated changeover valve 20 so
that the backflow preventer turns back to
shut-off position.
3. Operation
Backflow preventers of this type are normally in
the shut-off position. When water is drawn from
the downstream system, the differential
pressure in the backflow preventer rises. If the
must be provided above the
100 125 150
270 320
GB
differential pressure rises above 0.5 bar, the
hydraulic
operator causes the control valve to change the
backflow preventer into the flow position. When
the draw-off stops, the differential pressure then
falls again and the pressure sensor transmits a
signal to the control valve, which then returns
the backflow preventer to the normal shut-off
position.
The operating position is indicated on the spring
bonnet 3 .
• Shutoff position: Green spring bonnet 4 is
visible. The backflow preventer has shut off.
• Flow position: Green spring bonnet 4 is
not visible.
4. Inspection
The EN 805-6 (Specifications for installations
200
inside buildings conveying water for human
440
consumption - Part 5: Operation and
maintenance) must be regarded.
4.1 Testing of Function
• Open an outlet which is downstream of the
backflow preventer.
• Visually check that the backflow preventer
goes to the flow position - Green spring
bonnet is not visible (see chapter 3).
• If the backflow preventer does not go to the
shutoff position, check hydraulically actuated
changeover valve, the valve insert, seal
disc and seals as described in section 5 and
replace them if necessary.
4.2 Checking for Seal
• Visually check that no water is emitted when
backflow preventer is in the flow position (Green
spring bonnet is not visible).
• If water comes out, check the valve insert,
seal disc and seals as described in section 5
and replace them if necessary.
4.3 Checking the Safety Function
• Open an outlet which is downstream of the
backflow preventer.
☞
The backflow preventer must then go to the
flow position at the set pressure indicated
on the rating plate.
• The set pressure must be checked by
connecting a pressure measuring device
between the outlet and the backflow preventer.
• If the backflow preventer does not go to the
flow position at the given operating pressure,
check hydraulically actuated changeover valve,
the valve insert, seal disc and seals as
described in section 5 and replace them if
necessary.
☞
These inspections and tests should be
carried out at least once a year by the user
or by a specialist.
Depending on operating conditions, it may
be necessary to carry out these tests and
5
inspections more frequently.