WArninG
!
If flame propagation occurs when the
system pressure is higher than the
Maximum initial Operating Pressure, the
flame arrestor could be ineffective in
stopping the flame propagation.
Detonation State
Unstable (overdriven) detonations exist during a
deflagration to detonation transition (DDT) before a
stable detonation is reached. An unstable detonation is
the most severe condition where pressure and velocity
are at maximum values. Detonation arrestors rated for
unstable detonations may be placed in any location in
a piping system, provided installation is in accordance
with all sections of this manual.
Stabilized Burning
Refer to Table 3 and 6 for stabilized burning limitations
for the Detonation Flame Arrestors covered within the
scope of this document.
WArninG
!
Unlimited burning should not be allowed
in any flame arrestor, regardless of
its rating. in installations where there
is a potential for stabilized burning, it
is recommended that a temperature
sensor, alarm and shutdown system
be installed. Stabilized burning after
ignition creates additional hazards
in applications where there could be
a continuous flow of the flammable
mixture towards the unprotected side
of the flame arrestor. An overheated
Detonation Flame Arrestor will fail and
allow flame propagation to move into the
protected side of the process.
WArninG
!
Scorched, discolored paint or discolored
metal on unprotected (hot) side end
section and/or adjacent piping is possible
indication of a stabilized flame inside
the Detonation Flame Arrestor. This is
an abnormal condition that must be
corrected. Do not operate any system
where indications of stabilized burning
are observed. Effective corrective
measures must be taken to correct this
condition. Any Detonation Flame Arrestor
with indications of stabilized burning
must be removed from service and
thoroughly inspected by personnel with
appropriate training and qualifications.
WArninG
!
Temperature sensors must be used
with flame arrestors having 1 minute
ATEX burn ratings. never disconnect or
remove these devices.
installation
WArninG
!
Always make sure that the system is
at atmospheric pressure and there is
no ignitable gas that could flash when
either installing or maintaining the unit.
Connection
Enardo DFA Series are normally provided with CL150
raised or flat faced flanges. Other flanges such as CL300
are sometimes provided on special request. Make sure
the companion flanges installed in adjacent piping match
the flanges on the detonation flame arrestor.
Standard compressed fiber gaskets that withstands
temperatures of 450°F / 232°C or higher are normally
used, but other materials of equal or higher temperature
capability may be used at the customer’s discretion.
For proper torquing of the detonation arrestor to the
process piping, please refer to Tables 6, 7 and 8.
Positioning
CAUTiOn
The detonation flame arrestor is
fitted with lugs for lifting the element
assembly during servicing operations.
These lugs are not intended for lifting
the entire unit during installation.
Damage to the detonation flame arrestor
may result from improper lifting. The
unit should be lifted using appropriately
rated nylon (PA) straps rigged on the
outside of the tension studs. Detonation
flame arrestors fitted with temperature
sensors are directional dependant.
The sensor must be located on the
unprotected side of the arrestor.
6
Enardo DFA Series
Outside North
America Only
