Emerson Enardo EN FVFA Series User manual

EN FVFA Series
North America Only
Table of Contents
Introduction........................................................................................1
Specifications ....................................................................................2
Principle of Operation........................................................................4
Factors Affecting Flame Arrestor Performance..................................4
Installation .........................................................................................4
Maintenance......................................................................................5
Recommended Spare Parts ..............................................................8
Parts Ordering ...................................................................................8
EN Free Vent Flame Arrestor Series
Instruction Manual
D103771X012
Figure 1. Typical EN Free Vent Flame Arrestor
▲ WARNING
Failure to follow these instructions or to properly
install and maintain this equipment could result in
an explosion, re and/or chemical contamination
causing property damage and personal injury
or death.
Enardo™ ame arrestor must be installed,
operated and maintained in accordance with
federal, state and local codes, rules and
regulations, and Emerson Process Management
Regulator Technologies Tulsa, LLC instructions.
Failure to correct trouble could result in a
hazardous condition. Call a qualied service
person to service the unit. Installation, operation
and maintenance procedures performed by
unqualied person may result in improper
adjustment and unsafe operation. Either condition
may result in equipment damage or personal
injury. Only a qualied person must install or
service the ame arrestor.
Introduction
Scope of the Manual
This Instruction Manual provides instructions for installation, startup,
maintenance and parts ordering information for the EN Free Vent
Flame Arrestor (FVFA).
Flame Arrestor Classication
The flame arrestors within the scope of this document have been
tested and certified in accordance with EN ISO-16852 as end-
of-line deflagration flame arrestors and are therefore suitable for
unconfined deflagrations into an enclosure or vessel.
August 2020

1. The pressure/temperature limits in this Instruction Manual and any applicable standard or code limitation should not be exceeded.
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EN FVFA Series
North America Only
Specications
The Specifications section lists the specifications for the EN Free Vent Flame Arrestors. The following information is stamped on the
nameplate attached to the arrestor: model number, flange size and rating, maximum initial operating pressure, EN number (European
Standard), EU type examination certificate, notified body number, gas group, date of manufacture and serial number; other identification and
customer tag number are optional.
Available Constructions
See Table 1 and Figure 2
Gas Group
IIA and IIB3
Flange Sizes and Rating
2 to 16 in. / 50 to 400 mm
CL150 RF and CL150 FF
Housing Size
4 to 30 in. / 100 to 750 mm
Maximum Experimental Safe Gap (MESG)
See Table 2
Maximum Initial Operating Pressure(1)
Atmospheric
Maximum Operational Temperature (To)(1)
140°F / 60°C
Temperature Rating of Housing Gaskets(1)
Fiber Gaskets (standard): 450°F / 232°C
Graphite/Metal (optional): 1600°F / 870°C
Burning Time Rating
Less than 1 minute
Housing Material
Carbon steel, 304 Stainless steel,
316 Stainless steel and Hastelloy®
Element Material
304 Stainless steel, 316 Stainless steel
and Hastelloy®
Certication
EN ISO-16852:2016
Table 1. EN FVFA Series Available Construction
MODEL FLANGE SIZE HOUSING SIZE CERTIFICATION
In. mm In. mm IIA IIB3
EN-FVFA-0402 2 50 4 100 X X
EN-FVFA-0603 3 75 6 150 X X
EN-FVFA-0803 3 75 8 200 X X
EN-FVFA-0804 4 100 8 200 X X
EN-FVFA-1206 6 150 12 300 X X
EN-FVFA-1608 8 200 16 400 X X
EN-FVFA-2010 10 250 20 500 X X
EN-FVFA-2412 12 300 24 600 X X
EN-FVFA-3014 14 350 30 750 X
EN-FVFA-3016 16 400 30 750 X
Table 2. Maximum Experimental Safe Gap (MESG)
NATIONAL ELECTRIC
CODE (NEC) GROUP
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION (IEC) GROUP
MESG
TEST GAS LIST
In. mm
Group D Group IIA 0.035 >0.90 Propane
Group C Group IIB3 0.026 ≥0.65 Ethylene
Group B Group IIC 0.020 <0.50 Hydrogen
Hastelloy®is a mark owned by Haynes International, Inc.

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EN FVFA Series
North America Only
Hastelloy®is a mark owned by Haynes International, Inc.
Figure 2. EN Free Vent Flame Arrestor Available Constructions and Model Numbering System
EN /- - FVFA
Housing
Size
Connection
Size
IEC
Gas
Group
Housing
Material
Element
Material
Connection
Type
Options
04 = 4 in.
through
30 = 30 in.
01 = 1 in.
through
16 = 16 in.
IIA
IIB3
C = Carbon Steel
4 = 304 SST
6 = 316 SST
H = Hastelloy®
4 = 304 SST
6 = 316 SST
H = Hastelloy®
F = Flat face
ange
R = Raised
face
ange
2 - Temperature Instrumentation Port
3 - Pressure Instrumentation Port
4 = Miscellaneous
5 = Protective coating
6 = Special feature
MARKING PLATE (SEE TABLE 3)
WARNING
Flame Arrestors have installation and application limits
Type designation in accordance with ISO-16852:2016
DEF Lu/D = N/A BC: b; tBT = 1 min
Ex. G IIA To= 60°C
NOTE: Warning label for 2 to 12 in. IIA
Figure 3. Free Vent Flame Arrestor
HAZARDOUS LOCATION
Figure 4. Product Identication and Marking
Table 3. Marking Plate Information (See Figure 4)
INFORMATION DESCRIPTION
DEF Indicates product is a Deagration Flame Arrestor
Lu/D = n/a
The ratio of pipe length (between the potential ignition source and
the ame arrestor) and pipe diameter.
Indicates end-of-line conguration. Prevents unconned deagration
from entering a tank or enclosure
BC: b Indicates the ame arrestor is for short-time burning,
not to exceed 1 minute
Ex. G IIA Indicates the arrestor is rated for use in Explosion Group IIA vapors
Ex. G IIB3 Indicates the arrestor is rated for use with
Explosion Group IIB3 vapors
ToIndicates maximum operational temperature of ame arrestor
Note: Models Enardo EN-FVFA3014 and Enardo EN-FVFA-3016 available for Explosion
Group IIA vapors only.
WARNING
Flame Arrestors have installation and application limits
Type designation in accordance with ISO-16852:2016
DEF Lu/D = N/A BC: b; tBT = 8 min
Ex. G IIA To= 60°C
NOTE: Warning label for 14 and 16 in. IIA
HAZARDOUS LOCATION
WARNING
Flame Arrestors have installation and application limits
Type designation in accordance with ISO-16852:2016
DEF Lu/D = N/A BC: b; tBT = 1 min
Ex. G IIB3 To= 60°C
NOTE: Warning label for 2 to 12 in. IIB3
Markings
Nameplate Information
A nameplate will be attached to the arrestor and will contain the
following information:
Model Number: Ex. 1206/IIA (see model codication information
shown in Figure 2)
Flange Size and Rating: Ex. 6 in. CL 150
Maximum Initial Operating Pressure, Po: Ex. ATM
EN Number: Ex. ISO EN 16852
EU Type Examination Certicate Number
Notied Body Number: Ex. 0518
Gas Group: Ex. IIA or IIB3
Date of Manufacture
Serial Number
Other Identication (Optional)
Customer Tag Number (Optional)

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EN FVFA Series
North America Only
Principle of Operation
The EN Free Vent Flame Arrestors prevent flame propagation
by absorbing and dissipating heat using spiral wound crimped
ribbon flame cells. These cells allow maximum flow with maximum
protection. The EN Free Vent Flame Arrestor is used to stop the
propagation of confined and unconfined low pressure deflagrations.
It prevents an ignited atmospheric vapor cloud from propagating
beyond the flame arrestor into the vent line or tank.
EN Free Vent Flame Arrestors allow free venting and flame
protection for vertical vent applications. Designed with flanged
connections, this arrestor allows removal of the flame cell element
without their removal of the venting assembly.
Additional Protection Measures
Flame arrestors may be used with additional protection measures.
The overall safety of the combined installation shall be assessed,
taking account of any hazardous area classification (zones) and the
likelihood of additional ignition sources.
Limits of Use for EN Free Vent Flame
Arrestors (FVFA)
The following vapors are not within the scope of the products
covered by this manual:
• Explosive mixtures of vapors and gases, which tend to self-
decompose (e.g. Acetylene) or which are chemically unstable
• Carbon Disulphide, due to its special properties
• Mixtures other than gas-air or vapor-air mixtures (e.g. higher
oxygen-nitrogen ratio, chlorine as oxidant, etc…
• Minimum distance between ame arrestor connection and a
restriction on the protected side is 10 L/D, but not less than 3 m.
• Arrestors shall only be installed into piping with a nominal size
that is smaller than or equal to the nominal size of the ame
arrestor connection.
Factors A󰀨ecting Flame
Arrestor Performance
Methanol Warning
▲WARNING
Methanol is classied as a Group D (IIA) vapor,
however; our lab tests indicate that it exhibits
characteristics unlike other Group D (IIA) vapors
under certain conditions. We therefore recommend
that an arrestor rated for Group C (IIB3) vapors be
specied for methanol service.
Gas Group
The type of gas in the system determines its gas grouping and
therefore predetermines the type of arrestor element required.
The element must be designed to accommodate the specific gas
group that could possibly ignite and propagate in the system. The
more explosive gases require the flame cell to absorb the heat
more quickly and efficiently. The International Electrotechnical
Commission (IEC) groups gases and vapors into Groups IIA through
IIC categories depending on a number of factors including the
Maximum Experimental Safe Gap (MESG) of the gas.
Maximum Initial Operating Pressure
The EN Free Vent Flame Arrestor is intended to operate at
atmospheric pressure when at or near static flow conditions.
Burn Time Rating
△CAUTION
Temperature sensors must be used with this
product. The response time of the sensor must be
at least as fast as that of a Type K thermocouple
in a stainless steel sheath. The tip of the sensor
should be installed such that it is within 5 in. /
125 mm of the face of the element assembly. Never
disconnect or remove these devices.
All EN FVFA Series flame arrestors are rated for short time burning
with a temperature sensor in place. If no temperature sensor is
installed, this product is not suitable for short time burning.
Installation
▲WARNING
Verify that the ame arrestor being installed has the
appropriate gas group rating for your process. This
information is shown on the nameplate attached
to the element housing. Do not remove or alter
this nameplate.
Always make sure that the system is at atmospheric
pressure and there is no ignitable gas that could ash
when either installing or maintaining the unit.
Protected Side Pipe Warning
▲WARNING
For maximum safety, avoid bends and ow
obstructions within 10 pipe diameters but not less
than 3 meters on the protected (cold) side of the
ame arrestor.
Connection
Enardo™ flame arrestors are normally provided with CL150 raised
or flat face flanges. Other flange patterns including DIN patterns are
available upon request. Make sure the companion flange installed in
adjacent piping matches the flange on the flame arrestor. For proper
bolt torquing of the flame arrestor flange to the piping, please refer
to Tables 4 and 6.
Refer to Table 4 for proper bolt torquing of the arrestor connecting
flange to the process piping.
Positioning
▲WARNING
No instrument, tubing or other device whatsoever
shall circumvent the ame arrestor in such a
manner to allow a ame path to exist around
the ame element of the arrestor. When
instrumentation is installed in such a manner that

5
EN FVFA Series
North America Only
it creates a path circumventing the ame element
of an arrestor, measures must be taken to prevent
passage of ame through the instrumentation
device and/or system. Instrumentation must
be capable of withstanding the maximum and
minimum pressures and temperatures to which the
device may be exposed.
△CAUTION
The ame arrestor is tted 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 ame
arrestor may result from improper lifting. Heavy
units should be lifted using appropriately rated
Nylon (PA) straps rigged on the outside of the
tension studs.
The EN Free Vent Flame Arrestor should be positioned in a vertical
orientation. Models that have pressure taps are designed to allow
the installation of a pressure gauge determine blockage. The
pressure gauge will normally be mounted vertically.
Piping Expansions and Reductions
Adjacent to Flame Arrestors
An EN Free Vent Flame Arrestor may be installed in any vapor
control line that is smaller than or equal to the nominal pipe diameter
of the arrestor’s connection flanges.
Maintenance
1. Keep the element openings clean to prevent loss of efficiency
in absorbing heat. Remove the element assembly and clean
the elements to prevent the openings from becoming clogged
with particulate matter.
2. Clean the element with a suitable cleaning media (solvent,
soap, water or steam) then blow dry using compressed air.
Special care should be taken not to damage or dent the cell
openings as this would hamper the effectiveness of the unit.
3. Arrestor elements shall not be cleaned by rodding to remove
blockages, as this practice could damage the elements and
seriously impair the arrestor’s performance. If the arrestor
element cannot be cleaned satisfactorily, it must be replaced.
Table 4a. Torque Values for Raised Face Connection Flange (Steel Only)
NOMINAL PIPE DIAMETER NUMBER OF BOLTS
BOLT DIAMETER TORQUE
In. mm Ft-lbs N•m
1 4 0.50 12.70 9 12.20
1-1/4 4 0.50 12.70 13 17.63
1-1/2 4 0.50 12.70 18 24.40
2 4 0.63 16.00 35 47.45
2-1/2 4 0.63 16.00 41 55.59
3 4 0.63 16.00 60 81.35
3-1/2 8 0.63 16.00 34 46.10
4 8 0.63 16.00 43 58.30
6 8 0.75 19.05 80 108.5
8 8 0.75 19.05 109 147.8
10 12 0.88 22.4 101 136.9
12 12 0.88 22.4 135 183.0
14 12 1.00 25.0 168 227.8
16 16 1.00 25.0 159 215.6
Assumptions: Use of SAE grade 5 bolts or studs or stronger
No lubricant
Compressed mineral fiber material or similar
Notes: If lubricant is used on bolts, apply torque reduction factor listed in Lubricant Table. For best results hardened steel washers should be used on all cast flange bolted connections.
Table 4b. Torque Values for Flat Face Connection Flange (Steel Only)
NOMINAL PIPE DIAMETER NUMBER OF BOLTS BOLT DIAMETER TORQUE
In. mm Ft-lbs N•m
1 4 0.50 12.70 14 18.98
1-1/4 4 0.50 12.70 16 21.69
1-1/2 4 0.50 12.70 18 24.41
2 4 0.63 16.00 32 43.39
2-1/2 4 0.63 16.00 43 58.30
3 4 0.63 16.00 47 63.72
3-1/2 8 0.63 16.00 26 35.25
4 8 0.63 16.00 32 43.39
6 8 0.75 19.05 49 66.44
8 8 0.75 19.05 68 92.20
10 12 0.88 22.4 69 93.55
12 12 0.88 22.4 98 132.9
14 12 1.00 25.0 138 187.1
16 16 1.00 25.0 125 169.5
Assumptions: Use of SAE grade 5 bolts or studs or stronger
No lubricant
Elastomer < 70 Durometer Shore A
Notes: If lubricant is used on bolts, apply torque reduction factor listed in Lubricant Table. For best results hardened steel washers should be used on all cast flange bolted connections.

1
5
9
8
4
3
7
2
6
13
17
11
15
19
10
14
18
12
16
20
1
1
36
2
1
5
10
83
7
4
6
2
9
54
4
32
18
4 5
36
72
Figure 5. Flange Pattern Tightening Sequence
6
EN FVFA Series
North America Only
PATTERN 1 PATTERN 2 PATTERN 3 PATTERN 4
PATTERN 5
Table 5. Element Assembly Tightening Steps and Torque Values(1)
ENARDO™ EN FREE VENT FLAME ARRESTOR SERIES WITH
STEEL OR STAINLESS STEEL END SECTIONS ONLY(2) TIGHTENING STEPS AND TORQUE (FT•LB / N•m)
Model Pattern(3) Step 1 Step 2 Step 3 Step 4 Step 5
EN-FVFA-0401
EN-FVFA-0401.5
EN-FVFA-0402
EN-FVFA-0603
EN-FVFA-0802
EN-FVFA-0803
EN-FVFA-0804
1 Snug 20 / 27 50 / 68 - - - - - - - -
EN-FVFA-1206 2 Snug 20 / 27 50 / 68 - - - - - - - -
EN-FVFA-1608 3 Snug 25 / 34 50 / 68 80 / 108 - - - -
EN-FVFA-2010 3 Snug 25 / 34 50 / 68 75 / 102 100 / 135
EN-FVFA-2412 4 Snug 35 / 47 70 / 95 100 / 135 130 / 176
EN-FVFA-3014 and EN-FVFA-3016 5 Snug 35 / 47 70 / 95 100 / 135 130 / 176
1. Using machine oil as lubricant. See Bolt Lubrication section below and torque correction factors for other lubricants in Table 6.
2. Carbon steel element assembly fasteners are provided with a low friction polymer coating. No additional lubrication should be required. When stainless steel fasteners are provided,
lubrication is recommended to reduce tightening torque and to prevent potential galling.
3. See Figure 5.

7
EN FVFA Series
North America Only
4. If the flame arrestor sustained a burning event, thoroughly
inspect the element for any sign of damage. Replace the
element assembly if distorted crimps are visible, particularly
near the outer periphery of the flame element. Replace gaskets
if any damage is noted.
5. For best cleaning results, a high pressure sprayer with spray
wand should be used (1500 to 3000 psig / 103 to 207 bar) to
clean the entire element surface. The spray nozzle should be
held perpendicular to the surface being cleaned to maximize
spray media penetration into the element. Alternately spray
each side of the element surface until clean.
6. The cleaning interval should be governed by the amount and
type of particulate in the system to which it is installed and
must be determined by the user. To determine the maintenance
interval the user should check the element in the first few
months of operation to find how quickly particulate accumulates
in the cells.
Note
Under no circumstance should the element bank
be disassembled from its shell for cleaning
or replacement.
7. After cleaning, thoroughly inspect the element for damage. If
damaged, replace the element. Replace the element section as
a complete assembly.
Element Disassembly
▲WARNING
Isolate gas supply and bring system to
atmospheric pressure to prevent ignitable gas
from ashing while performing maintenance.
1. Remove the top wing nuts.
2. Remove the hood and screen. It is not necessary to remove the
hex nuts located directly under the hood. These nuts are used
for positioning the hood.
△CAUTION
The screen might have sharp edges. Use care
when handling.
3. Remove the upper nuts from the tensioning studs.
4. Remove the upper flange.
5. Remove the element assembly.
△CAUTION
Some element assemblies are heavy and will
require the use of adequate equipment and
manpower to prevent injury.
Element Re-assembly
1. Thoroughly clean the gasket sealing faces being careful not to
damage the sealing surface. Lightly grease one side of a new
gasket and place it in the machined recess of the interior flange
on the conical sections and in the upper flange.
2. Replace the flame element assembly with a new assembly or
properly cleaned and inspected existing unit.
3. Re-assemble in the reverse order of disassembly.
4. Tighten the tensioning studs as detailed below:
△CAUTION
Excessive or uneven torquing can cause
permanent damage to gaskets and housing.
Tools/Supplies Required:
• Torque wrench appropriate for the specified torque.
• Socket wrenches of the proper size to fit the hex nuts
being tightened.
• Molydisulfide based lubricating paste. Molykote®G-n
or equivalent.
• Brush suitable for applying lubricant to the studs.
• Wiping rags necessary for the clean-up of excessive lubricant.
Procedure:
1. Use studs and nuts that are free of visible contamination
and corrosion.
2. Apply lubricant to the threads of the stud protruding outboard
of the interior flanges and to the face of the hex nuts which
will contact the flange.
3. Assemble the nuts to the studs such that the amount of thread
extending outboard beyond the nut is approximately equal on
both ends.
4. Tighten the nuts to the values shown in Table 5 following the
designated sequence, repeating the sequence as shown.
Flange pattern tightening sequences are shown in Figure 5.
Table 6. Torque Correction Factors for Common Lubricants
DESCRIPTION COEFFICIENT OF FRICTION MULTIPLY TORQUE VALUE IN TABLE 6 BY
Machine Oil f = 0.15 1.00
API SA2 Grease f = 0.12 0.80
Nickel Based Lubricant f = 0.11 0.73
Copper Based Lubricant f = 0.10 0.67
Heavy-Duty Lubricating Paste f = 0.06 0.40
NOTE: Carbon steel element assembly fasteners are provided with a low friction polymer coating. No additional lubrication should be required. When stainless steel fasteners are
provided, lubrication is recommended to reduce tightening torque and to prevent potential galling.
Molykote®G-n is a mark owned by Dow Corning Corporation.

EN FVFA Series
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North America Only
Emerson Automation Solutions
Americas
McKinney, Texas 75070 USA
T [phone]
[phone]
Tulsa, OK 74146 USA
T [phone]
Europe
Bologna 40013, Italy
T [phone]
Asia Pacic
Singapore 128461, Singapore
T [phone]
Middle East and Africa
Dubai, United Arab Emirates
T [phone]
D103771X012 © 2014, 2020 Emerson Process Management Regulator
Technologies, Inc. All rights reserved. 08/20.
The Emerson logo is a trademark and service mark of Emerson
Electric Co. All other marks are the property of their prospective owners.
Enardo™ is a mark owned by Regulator Technologies Tulsa, LLC, a
business of Emerson Automation Solutions.
The contents of this publication are presented for informational purposes
only, and while every e󰀨ort has been made to ensure their accuracy,
they are not to be construed as warranties or guarantees, express or
implied, regarding the products or services described herein or their use
or applicability. All sales are governed by our terms and conditions, which
are available upon request. We reserve the right to modify or improve the
designs or specications of such products at any time without notice.
Emerson Process Management Regulator Technologies
Tulsa, LLC does not assume responsibility for the selection, use or
maintenance of any product. Responsibility for proper selection, use
and maintenance of any Emerson Process Management Regulator
Technologies Tulsa, LLC product remains solely with the purchaser.
Bolt Lubrication
Enardo™ provides low friction polymer coatings on carbon steel
element assembly fasteners. No additional lubrication should be
required. When stainless steel fasteners are provided, lubrication
is recommended to reduce tightening torque and to prevent
potential galling.
Lubrication will affect required torque of clean fasteners in good
condition more than any other factor. In fact, 90% of applied torque
goes to overcome friction while only 10% actually stretches the bolt.
Table 5 assumes that only machine oil is used as a lubricant. Table 6
lists several common lubricants and their effect on torque required to
stretch bolts to 50% of their yield strength. Most are available from
local bearing distributors.
Recommended Spare Parts
For installations that require frequent maintenance and minimum
downtime it is recommended that the user purchase a spare
element assembly and several spare element gaskets. The spare
element assembly can be installed immediately and the dirty
assembly can then be cleaned and be stored as a spare for the next
maintenance interval.
Note
Element gaskets should be replaced each time the
cell assembly is loosened and removed to insure a
gas tight seal.
Parts Ordering
When corresponding with your local Sales Office about this
equipment, always reference the equipment serial number and
model number stamped on the nameplate.