Conditions for installation
4.3 Conditions for installation
The Q-Rohr®-3 must be installed in such a
way that it is not possible for dust to collect
in front of the rupture disc.
It should ideally be installed in a vertical
position or angled upwards.
The area adjacent to the discharge point
shall be clear of combustible dusts in
accordance with NFPA 68 section 6.9.5.
If you wish to fit several Q-Rohr®-3s to a
container or apparatus, use Q-Rohr®-3s
which are identical in size. You can also use
Q-Rohr®-3s which differ in size by no more
than one nominal width value, e.g. a
Q-Rohr®-3 DN 600 and a Q-Rohr®-3
DN 700.
To install horizontally, fit holders between
the walls or ceiling and the hoist eyebolts on
the Q-Rohr®-3 to secure it. Further
information about this can be found in the
section Horizontal installation starting on
page 17.
Risk of damage to the Q-Rohr®-3 and
facility due to a faulty flange.
Fit the flange on a self-supporting basis.
The flange needs to be designed and made
to hold both the weight of the Q-Rohr®-3 and
all recoil forces on its own.
When release with explosion venting occurs,
the container is exposed to powerful recoil
forces. These can be determined with
reference to European standard EN 14491.
Investigations have demonstrated that recoil
forces are up to approx. 50% lower when
pressure is vented with a Q-Rohr®-3 than in
unrestricted venting with a rupture disc of
the same size. However, the 50% of the
recoil force is transferred to the flange and
impacts there as an additional force on top
of the weight of the Q-Rohr®-3. The flange
therefore has to be designed, made and
installed to withstand these forces.
For further information about calculating the
recoil forces and the design and dimensions
of the flange, please contact REMBE®
Customer Service.
For an overview of the flange dimensions
and boreholes, please refer to the Appendix
starting on page 28.
4.4 Conditions during operation
When the Q-Rohr®-3 is in operation, its
safety zone may only be entered for short
periods for carrying out checks.
Keep the outside of the filter packing and the
safety zone around the Q-Rohr®-3 free of
dust accumulations by cleaning at regular
intervals. This applies especially where the
Q-Rohr®-3 is used in areas falling under
Zone 22 in accordance with ATEX Directive
1999/92/EC; Class II, Div.2 per NFPA 70,
NEC regarding explosion risk.
Shut down the facility immediately if the
integrated rupture disc releases.
All personnel must leave the operations area
immediately when the release alarm signal
is given.
Further information about what to do after a
release can be found in the section Making
the Q-Rohr®-3 ready for use again after a
release starting on page 23.
4.5 Conditions in the event of an
explosion
4.5.1 The explosion process
Dust or gas explosions are rapid exothermal
combustion reactions involving a rapid increase in
pressure. Without protective measures, explosions
can generate very high pressure and temperature
levels. Typical values are in the order of 8 to 10 bar
and temperatures of up to approx. 4532 0F
(2500 0C).
The Q-Rohr®-3 vents the explosion pressure to
reduce it to a level which is harmless for the facility.
It reduces the combustion temperature of the vented
gases to a harmless level. These values will vary
according to the application. Within close proximity
of up to 3.3 ft (1 m), the following values are not
exceeded:
Maximum exhaust gas temperature approx.
2120 F (100 0C), momentary (t < 1 second)
Maximum external pressure levels < 5 mbar,
momentary (t < 1 second).
Steam and combustion gases are released during
combustion. However, the explosion is a short
event, meaning that the rate of combustion gas
release is relatively low compared to a fire.
