Gas Line; Gas Feeding Line; Gas Supply Pressure - Riello RS 70/EV Installation, Use And Maintenance Instructions

4.8

Gas line

The gas train is type-approved according to standard UL 795 and
is supplied separately from the burner.
The gas train can enter the burner from the right or left side, de-
pending on which is the most convenient, see Fig. 19.
The gas train must be connected to the gas attachment 1)(Fig. 19)
with the flange 2), the gasket 3) and the screws 4) supplied with the
burner.
The gas solenoids must be as close as possible to the burner, to
ensure that the gas reaches the combustion head within the safety
time of 3s.
Ensure that the maximum pressure necessary for the burner is in-
cluded in the calibration field of the pressure regulator (colour of the
spring).
The pilot gas train must be connected to the gas attachment
5)(Fig. 19) and can enter the burner from the right or left side.
See the accompanying instructions for the
adjustment of the gas train.
WARNING
4.8.1

Gas feeding line

It must be type-approved according to required standards and is
supplied separately from the burner.
Key (Fig. 20)
1 Gas input pipe
2 Manual valve
3 Pressure regulator
4 Minimum gas pressure switch
5 1st safety shut off valve
6 2nd safety shut off valve
7 Standard issue burner with flange gasket
8 Gas adjustment butterfly valve (*)
9 Burner
10 Maximum gas pressure switch (*)
(*) On the burner
4.8.2

Gas supply pressure

The diagram (Fig. 21) show minimum load losses at combustion
head depending on the maximum burner output operation with nat-
ural gas (G 20).
Gas pressure is measured at the test point 1)(Fig. 21), with:
• Combustion chamber at 0 mbar
• Burner working at maximum output
• Ring nut 2)(Fig. 16) adjusted as in the diagram of Fig. 15
NOTE
To know the approximate output at which the burner is operating at
its maximum:
– subtract the combustion chamber pressure from the gas pres-
sure measured at test point 1)(Fig. 21);
– find, in the diagram (Fig. 21) the pressure value closest to the
result you want;
– read the corresponding output on the left.
Installation
D2438
Example
• Maximum output operation
• Ring nut 2)(Fig. 16) adjusted as in the diagram of Fig. 15
• Gas pressure at test point 1)(Fig. 21)
• Pressure in combustion chamber
A maximum output of 2000 MBtu/hr corresponds to 1.97 "wc pres-
sure.
This value serves as a rough guide; the effective output must be
measured at the gas meter.
NOTE
To know the required gas pressure at test point 1)(Fig. 21), set the
maximum output required from the burner operation, then:
– find the nearest output value in the table for the burner in ques-
tion.
– read, on the diagram (Fig. 21), the pressure test point 1)
(Fig. 21);
– add this value to the estimated pressure in the combustion
chamber.
23
D2393
=
=
3.15 - 1.18 =
Fig. 19
GAS PILOT LINE
MAIN GAS LINE
Fig. 20
3.15 "wc
1.18 "wc
1.97 "wc
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