HEALTH & SAFETY
COMPREHENSIVE SAFETY
REMBE
EXPLOSION ISOLATION WITH Q-FLAP RX™
Explosion Isolation is absolutely necessary
for a comprehensive safety concept.
Without explosion isolation, the safety
concept is not just insufficient, it also
represents wasted money for operators,
because: Throughout the industry, vessels,
silos and other parts are often connected to
each other by pipelines. If a dust explosion
occurs in one equipment, this also
enhances the risk of flames and pressure
propagation to other parts of the plant.
Pre-compression and flame jet ignition
exacerbate the explosion severity in
interconnected vessels. The result is a series
of secondary explosions that may cause
even more catastrophic damage.
An explosion isolation system prevents
deflagrations from propagating and thus
minimises the effects of an explosion.
Adjoining plant components are optimally
protected. A distinction is made between
active and passive systems:
Passive isolation systems such as explosion
isolation flap valves make use of the
overpressure of the explosion for their
operating principle:
PASSIVE EXPLOSION
ISOLATION - THIS IS HOW IT
WORKS
Passive explosion isolation systems respond
purely mechanically to the propagation of
pressure through its constructive design.
Under normal operation, an explosion valve
in a pipeline is kept open by the available
flow. When an explosion occurs, the valve
is closed by the spreading of the pressure
front, thus effectively preventing the
pressure and the flames from propagating
any further.
ONE FUNCTION, DIFFERENT
REQUIREMENTS
Even if the function of an explosion
isolation flap valve is size-independent,
the requirements for a wide variety of
processes and industries vary greatly.
While in the pharmaceutical and chemical
industries in particular explosion isolation
flap valves are typically only installed in
nominal pipe sizes up to DN 400, especially
on decentralised aspiration systems of the
food industry, for example, larger nominal
98
PECM Issue 39
pipe sizes between DN 450 and DN 710 for
central dust extractors can quickly become
necessary. In the grain, wood and heavy
industry, nominal pipe sizes from DN 800 to
DN 1250 are mainly applied.
OPTIMUM FULFILMENT OF
REQUIREMENTS INSTEAD OF
ONE-FOR-ALL
The standard EN 16447 defines the general
requirements for explosion isolation
flap valves. Like any standard, it can only
provide general recommendations and
specifications, but cannot address every
application in detail.
Obviously, however, an explosion isolation
flap valve DN 250 used in the chemical
industry must meet different requirements
than its DN 1250 counterpart installed in a
grain or wood processing plant.
While the first application above all requires
a high-quality design, the operators of
grain mills or particleboard plants with their
characteristic large pipe diameters want
safety devices that are as easy to handle as
possible.
The Q-Flap RX™ explosion isolation flap
valve, a joint development of the explosion
safety specialists REMBE (Germany) and
RICO (Switzerland), offers three different
design versions. Developed on the basis
of many decades of experience the two
companies have accrued with regard to
the different customer requirements, the
nominal pipe sizes from DN 140 to DN
710 feature an inspection flap, the largest
nominal pipe sizes (up to DN 1250), on the
other hand, have a modular design so that
maintenance and servicing can be carried
out easily and thoroughly.
Through the swing ´n slide closing principle
integrated into the nominal pipe sizes up
to DN 710, the valve blade not only rotates
into the closed position, but also slides
horizontally into the closed position at
the same time. This ensures an even more
reliable sealing of the entire cross-section.
In addition to the features mentioned
above, the Q-Flap RX™ enables high K St
values, flexible installation distances and
maximum strengths.
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