Rinnai aiM 115, User And Installation Manual

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26
Shut-off valve
Housing
Reduction system of
1st stage
Filtering organs
Fuel shut-off
valve
2nd stage reducer
1.5 bar inlet
32 mbar output
In an LPG system it is always advisable to position both pressure reducers, both the first and the
second stage, to limit the impact of climatic variations on the pressure inside the cylinder and ensure
supply more stable and continuous gas. The first stage regulator must be calibrated at a pressure
ranging from 0.5bar (min) to 1.5bar (max) and must always be followed by a second stage reducer.
The second stage regulator must be calibrated at a pressure of 32mbar (or 35mbar with gas filter installed
downstream of the same). These values must not be altered: the appliance would not only have a worse
combustion (therefore less performance) but could switch off in case of too low pressures or, on the contrary,
do not give consent for ignition with too high pressures, causing possible damage to the gas valve group.
For Rinnai aiM heat generators, a pressure reducer must be installed for each appliance with adequate
capacity. In the case of appliances in cascade, each generator should have its own reducer. Alternatively,
a single reducer can be installed with a flow rate equal to the sum of the single reducers.
Indicative diagram of LPG or Propane gas
LPG gas pipe sizing table
A table is provided for estimating the diameter of the pipe, depending on the length of
the same and of the installed power
Installed
power
LPG gas
flow
Single pressure
reducer with
flow rate
Maximum equivalent piping lengths (meters)
kW m
3
/h kg/h 3/4" 1" 1" 1/4 1" 1/2 2" 2" 1/2
65 4.76 15 40 120 - - - -
85 6.22 15 25 75 - - - -
115 8.42 30 15 40 150 - - -
130 9.51 30 12 30 120 250 - -
150 10.98 45 8 25 100 200 - -
170 12.44 45 6 20 75 160 - -
195 14.27 45 5 15 60 130 - -
230 16.83 60 - 12 50 100 - -
255 18.66 75 - 10 40 80 250 -
260 19.03 75 - 10 40 80 250 -
340 24.89 90 - 6 20 50 150 -
345 25.25 90 - 6 20 50 150 -
450 32.94 135 - - 15 30 90 -
460 33.67 135 - - 15 30 90 -
600 43.91 180 - - 8 18 60 200
The table is purely indicative and simplified, therefore it does not constitute any commitment or responsibility on
the part of Rinnai Italia, nor does it intend to replace the work of the plumbing and heating designer where the
intervention is required
It is recommended, in case of storage of
LPG tanks, to pay attention to:
•
LPG storage tanks, which may
contain gas residues inert (eg
nitrogen), which deplete the mixture
delivered to the appliance causing it
to malfunction o no ignition;
•
composition of the LPG mixture.
During the storage period in
the tanks a stratification of the
components of the blend. This can
cause a variation of the calorific
value of the LPG supplied to the
appliance with a consequent
variation of the performance of the
same.
To have the correct mixture between the
components that make up the LPG the
tanks are added with substances oily
so-called “paraffins” (hence not even the
cylinders of only propane).
During gasification the “paraffins”,
pushed along the tube adduction by the
gas pressure, they end up depositing on
the group gas valves of the appliance.
This phenomenon takes on so much
relevance greater when the volume of
the cylinder decreases, as the draft is
find closer to the bottom.
To protect yourself from paraffin reflux it
is appropriate:
•
install a gas filter, supplied on
request by Rinnai (cod. FGPLDN20);
•
creation of a double curl on the gas
supply.
For proper operation it is necessary that
the static pressure and the dynamic
pressure of the LPG gas are not lower
than 32mbar and 28mbar respectively. In
case of higher values, it is reccomended
the installation of an appropriate pressure
reducer.
Requirements and conditions
Gas supply circuithv