PART II: INSTALLATION
14
1-a) in case of threaded joints: use proper seals according to the gas used;
1-b) in case of flanged joints: place a gasket (no. 1A..1E - Fig. 6) between the elements
2)
fasten all the items by means of screws, according to the diagrams showed, observing the mounting direction for each item;
NOTE:
the bellows unit, the manual cutoff valve and the gaskets are not part of the standard supply.
The procedures of installation fo the gas valves are showed in the next paragraphs, according to the gas train used:
z
threaded gas trains with Siemens VGD20..
z
flanged gas trains with Siemens VGD40..
The procedures of installation fo the gas valves are showed in the next paragraphs, according to the gas train used:
z
threaded gas trains with Siemens VGD20..
z
flanged gas trains with Siemens VGD40..
3.2 Siemens VGD20.. and VGD40.. gas valves - with SKP2.. (pressure governor)
Mounting
z
When mounting the VGD.. double gas valve, two flanges are required (as for VGD20.. model, the flanges are threaded); to prevent
cuttings from falling inside the valve, first fit the flanges to the piping and then clean the associated parts;
z
install the valve;
z
the direction of gas flow must be in accordance with the direction of the arrow on the valve body;
z
ensure that the bolts on the flanges are properly tightened;
z
ensure that the connections with all components are tight;
z
make certain that the O-rings and gaskets between the flanges and the double gas valve are fitted.
z
Connect the reference gas pipe (
TP
in figure; 8mm-external size pipe supplied loose), to the gas pressure nipples placed on the
gas pipe, downstream the gas valves: gas pressure must be measured at a distance that must be at least 5 times the pipe size.
Leave the blowhole free (
SA
in figure). Should the spring fitted not permit satisfactory regulation, ask one of our service centres for a
suitable replacement.
ATTENTION: once the gas train is mounted according to the diagram on Fig. 6, the gas proving test mus be per-
formed, according to the procedure set by the laws in force.
ATTENTION: it is recommended to mount filter and gas valves to avoid that extraneous material drops inside the
valves, during maintenance and cleaning operation of the filters (both the filters outside the valves group and
the ones built-in the gas valves).
Caution: the SKP2 diaphragm D must be vertical (see Fig. 10).
WARNING: removing the four screws BS causes the device to be unserviceable!
Fig. 7
Fig. 8
Fig. 9
BS
BS
SKP1.
SKP2.
BS
BS
SA
SA
TP
D
7631z05/0101
SIEMENS VGD..MOUNTING
POSITIONS
Summary of Contents for Low NOx Series
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