PIETRO FIORENTINI HBC 975, Manual

Page: 24 / 156

24
HBC 975
EN
Use, maintenance and warning manual
SLAM-SHUT VALVE | SAFETY | REV. 00
3.3.2 - TABLE OF RESIDUAL RISKS FOR POTENTIALLY EXPLOSIVE ATMOSPHERES
Table 3.11 indicates the conditions that can cause the HBC 975 slam-shut valve to generate a potentially explosive at-
mosphere.
The table is valid for use with natural gas with a density of no more than 0.8; for different densities, the installation and
environmental conditions must also be evaluated.
WARNING!
If the gas used is a combustible gas, the installation area of the equipment is defined as a “danger zone”
as there are residual risks that potentially explosive atmospheres may be generated.
There must be no effective sources of ignition in “danger zones” and in close proximity thereto.
Operating
conditions
Potentially
explosive
atmosphere
Regulatory references
Management measures
included in the instructions
for use and warning
First start-up No
• During the production cycle and
before the CE marking according
to Directive 2014/68/EU, the ex-
ternal tightness of the equipment
is checked at a value of 1.1 PS,
in accordance with Standard EN
14382.
• Before commissioning, the ex-
ternal sealing of the system por-
tion on which the equipment is
installed is checked at a suitable
pressure (in accordance with
the provisions of standards EN
12186 and EN 12279).
The instructions for use indicate
the need to meet the requirements
of Standards EN 12186 and EN
12279.
Operation in
normal conditions
No
The indications in the previous point
apply, in addition:
• the equipment is installed out-
doors or in an environment with
natural ventilation (in accordance
with Standards EN 12186 and
EN 12279);
• the installation is subject to sur-
veillance according to current
national rules/good practice/
the equipment manufacturer’s
instructions (in accordance with
the provisions of Standard EN
12186 and Standard EN 12279).
The instructions for use indicate
that:
• any environment in which
the equipment is installed
must meet the requirement of
Standards EN 12186 and EN
12279;
• periodic checks and main-
tenance must be carried out
during surveillance in accord-
ance with the national rules
in force (if any), and with the
specific manufacturer’s rec -
ommendations.
Breakage of the
pressure switch
diaphragm
(malfunction)
No
This event must be considered a rare
malfunction.
All atmospheric pressure chambers
delimited on at least one side by a
diaphragm must be channelled to
a safe area (in accordance with the
provisions of Standard EN 12186 and
Standard EN 12279).
The instructions for use indicate
the need to meet the requirements
of Standards EN 12186 and EN
12279.
Breakage of other
non-metallic parts
(malfunction)
No
This type of malfunction is not rea-
sonably expected as it involves static
sealing (to the outside).
-