27
GOVERNORS NOR
TH AMERICA
LOW PRESSURE GAS REGULATOR
|
SAFETY
|
REV. A
US
Operation, maintenance and warning manual
3.6.2 - RESIDUAL RISKS TABLE FOR POTENTIALLY EXPLOSIVE ATMOSPHERES
Tab. 3.12 shows the conditions that can lead to the generation of potentially explosive atmosphere by pressure regulators
GOVERNORS NORTH AMERICA.
The table is valid for use with natural gas with a density not exceeding 0.8; for different densities, installation conditions
and environmental conditions will also need to be evaluated.
If the gas used is a combustible gas, the area where the equipment is installed is called a “danger zone”
because there are residual risks of the formation of potentially explosive atmospheres where it is impera
-
tive that no effective ignition sources are present.
Operating condi-
tions
Potentially ex
-
plosive atmo-
sphere
Normative References
Management measures in-
cluded in the operation,
maintenance and warning
manual
First start-up
No
• During the production cycle, the
external tightness of the equip-
ment is verified according to UNI
11655:2016.
• Prior to commissioning, the exter-
nal tightness of the portion of the
system on which the equipment
is installed is checked according
to the requirements applicable
at the place of installation (when
installed in pressure-reducing
systems, the requirements of
UNI EN 12186:2014 and UNI
EN12279:2007 shall be met).
The manual indicates the need to
perform external leakage testing
and, when applicable, meet the re-
quirements of UNI EN 12186:2014
and UNI EN 12279:2007.
Normal operating
conditions
No
The previous point applies and also
the installation:
• of the equipment is outdoors or
in a naturally ventilated environ-
ment according to the require-
ments applicable at the place of
installation, or when applicable
according to EN 12186:2014
and EN 12279:2007;
• is subject to supervision accord-
ing to applicable national regu-
lations, good practice, and the
instructions of the Equipment
Manufacturer.
The manual states that:
• the environment, if any, in
which the equipment is in-
stalled shall meet the ventila-
tion requirement for the instal-
lation site, or, when applicable
as outlined in EN 12186:2014
and EN 12279:2007;
• periodic inspection should be
carried out during surveillance
in accordance with applicable
national regulations (if any)
and the Manufacturer's spe-
cific recommendations.
Breakage of the
membranes
No
This event should be considered as a
rare malfunction.
The manual indicates the need to
meet periodic verification require-
ments in accordance with the re-
quirements at the place of instal-
lation.
Breakage of other
non-metallic parts
(malfunction)
No
This type of malfunction is not rea-
sonably expected since it involves
static (outward) seals, which cannot
generate any external leakage.
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Summary of Contents for 30051
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