Installation, Operation & Maintenance
Model 7758A
Stable Detonation Flame Arrester
ATEX Certified
Ref. ID 97895
IOM 7758A –ATEX
April 25, 2013
1
IOM-7758A
Section
Page
Introduction
2
Specifications
1
Design & Function
3
Installation
3
Maintenance
4
Model Identification
7
Product Limited Warranty
7
Tables
Bolt torque
4 & 5
MESG tables
6
Attachments
Drawing A-93536
Test reports [as required]
0.025" [0.65 mm]
Burn Time
Emergency Function
Size
Time
Trigger Time
8”-12"
Table of Contents
CERTIFICATION
Groth Model 7758A stable detonation flame
arresters are manufactured in compliance with the
ATEX Directive 94/4/EC, as confirmed by
Certificate
IBExUXXXXX X. This certification covers
the following sizes, materials and limits for use.
Sizes included are all those shown on drawing A-
93536. Materials included are all materials that
satisfy the strength and pressure ratings specified
on these drawings.
These arresters are suitable for in line unstable
detonations and short time burning.
Explosion Gas
IIB3
Group
INTRODUCTION
This manual is intended to provide recommended
procedures and practices for installation, operation
MESG of
vapor mixture
Operating
Temperature
≥
o
F to 140oF [-20oC to 60oC]
–4
and maintenance of the Groth Model 7758A stable
detonation flame arrester without restriction. Any
Maximum Allowable
*Temperature Sensor
standard procedures and practices developed for a
specific plant or process should supersede this
manual. Although this manual cannot cover all
Connection
Burn
possible contingencies, following these guidelines
will provide safe, reliable detonation flame arrester
service.
The arrester shall be treated as a safety device and
(200 -305 mm)
30
Minute
s
15 Minutes
must be maintained by a knowledgeable repair
technician. Carefully read and understand this
Manual before installing or servicing this product.
Groth Corporation offers repair services for all
products manufactured by the Tank Protection
Division.
For information not contained in this manual, please
contact:
Groth Corporation
A Continental Disc Company
13650 North Promenade Blvd.
Stafford, TX 77477
Phone 281-295-6800
Fax 281-295-6999
Each temperature sensor with respect to connection size has
*
a trigger emergency function within half of the burn time.
Must be installed with integrated temperature
sensor(s), Groth P/N 93219005 or equal.
INTEGRATED TEMPERATURE SENSORS
Detonation flame arresters for short time
burning must be fitted with one or more
integrated temperature sensors, taking into
account the intended orientation of the flame
arrester. These arresters may be used in
systems and situations where the flow of the
flammable mixture can be stopped within one
minute.
2
IOM-7758A
Ref. ID 97895
Groth model 7758A stable detonation flame
A short time burning detonation flame
and must have a flame monitoring system
capable of shutting down the vapor flow
within a specified time.
A detonation flame arrester may be exposed to
antaneous pressure spikes in excess of
1000 PSI. Any instrumentation attached to
the arrester must be capable of continued
operation in this environment.
arresters were tested with one Groth integrated
temperature sensor, P/N 93219005, installed on
the ignition side. All arresters are manufactured
with a minimum of either one thermowell or one
thermocouple port, positioned to align the
thermocouple with the face of the element.
Multiple thermowells or ports may be on one or
both faces as specified by the purchaser. Groth
temperature sensors may also be installed as
specified.
If the purchaser installs an integrated
temperature sensor, it must be an ATEX
approved devise, installed in the Groth
thermowell such that the sensor contacts the
bottom of the thermowell.
design of the system in which it is used, the arrester
bases can include optional ports for thermocouples
or pressure monitoring devices. These devices can
activate warning or shutdown systems if abnormal
conditions are detected. Both bases may be
equipped with large diameter inspection/clean-out
ports for in-line maintenance of the element. If
element removal is required for inspection,
maintenance or replacement see maintenance
instructions.
Note
arrester cannot withstand a continuous flame,
DESIGN AND FUNCTION
Groth's detonation flame arresters are proven to
prevent flame propagation in gas piping systems
which contain flammable gas/vapor mixtures. The
arrester must prevent flame passage under certain
specified conditions while permitting free flow of
gas/vapor through the system. Thus it protects
vulnerable equipment or components of the system
from damage due to explosive pressures caused by
gas/vapor ignition in another part of the system.
The detonation flame arrester must be used under
only those operating conditions for which it was
designed and tested.
The flame arresters consist of two main
components, the arrester bases and the flame
element housing assembly. The bases serve as
the connecting interface to the piping system. The
housing retains and supports the flame element.
Both components are essential in stopping the
passage of the flame.
The flame element consists of multiple layers of
stainless steel wire cloth, laminated and sintered
into a strong, ductile, corrosion resistant and
uniform sheet. The sheets are cut to various sizes
and fit into cylindrical steel housings. The element
is supported by rigid beams, securely welded into
the housing to withstand the extreme pressures of
an overdriven detonation. Each nominal size
arrester can be supplied with various diameter
elements to provide the required flow capacity.
The bases must also withstand the detonation
pressures while conveying the burning vapors and
flame front to the element. Depending on the
WARNING
inst
INSTALLATION
Operating Conditions:
Based on the testing conditions, Groth Model
7758A detonation flame arrester may be installed in
piping systems where:
1. The MESG of the vapor constituent(s) is greater
than or equal to 0.025" (0.65 mm).
2. System operating pressure is less than or equal
to the nameplate pressure [see test results,
page 1].
3. Normal operating temperature is between -
o
F (-25o C) and 140o F (60o C).
13
4. The piping system in which the detonation
arrester is to be installed must not exceed the
arrester flange size.
WARNING
2
IOM-7758A
Ref. ID 97895
The 7758A detonation flame arrester may NOT be
Table 1
PIPE FLANGE STUD
TORQUE CHART
Lb.Ft. (Nm)
Size
Torque
8 [200]
111 [150]
10 [250]
170 [230]
12 [300]
170 [230]
effective in stopping flame propagation in systems
which contain vapors with an MESG less than
0.025" [0.65 mm] or when any of the operating
conditions are exceeded.
All Groth Detonation flame arresters are bidirectional and can be used in vertical or horizontal
piping systems.
This series of flame arresters all have 150# ANSI
flanges, or DIN/JIS flanges of equal pressure rating.
Please follow the torque guidelines listed in Table 1
for flange make-up torque.
WARNING
The flame arrester housings or adjacent piping
may have various pipe taps for pressure sensing,
temperature sensing, condensate drainage, etc.
Never connect such taps to a common line or
system as this could provide a flame bypass around
the flame arrester element.
The following guidelines should be observed at
installation:
1. Remove any flange protectors and discard all
packing material.
2. Inspect the gasket seating surface of the mating
flanges. It must be clean, flat, and free of
scratches, corrosion and tool marks.
3. Inspect the gasket; make sure that the material
is suitable for the application.
4. Lubricate all studs and nuts with an appropriate
thread lubricant. If the arrester will see high
temperature service or stainless steel fasteners
are used, select an anti-seize compound such
as moly-disulfide.
5. Center the gasket within the bolt circle.
WARNING
The lifting eye(s) on the element housing are
to be used for handling the housing only
during inspection and maintenance. DO NOT
use these eyes to lift the entire detonation
flame arrester assembly.
6. Set the arrester between its mating flanges or
nozzle. Position the lifting handles and jacking
bolts to facilitate future removal of the flame
arrester housing. Position the drain and
instrument ports to provide proper access and
function. (See Maintenance Instructions).
Install the studs and tighten nuts hand tight.
Notes:
• When installing the Models 7758A in a
horizontal pipeline, use the lowest 1" ports to
drain condensed vapors from the housing.
Note previous warning when connecting the
drain piping.
7. Torque all fasteners to half the value listed in
Table 1 in a staggered, alternating pattern to
provide an evenly compressed gasket joint.
• (Torque is an average value based on a nitrile
binder synthetic gasket, 1/32" thick and
lubricated threads).
8. Make up the final torque and check that no
further nut rotation occurs at the specified
torque value.
WARNING
After installation, all connections must be
inspected for vapor leakage. This may be
accomplished by static test, gas detector, or
"bubble" test using a soap solution.
3
IOM-7758A
Ref. ID 97895
MAINTENANCE
CAUTION
For maximum operating efficiency the element of a
flame arrester must be inspected and maintained at
regular intervals. Frequency of inspection should
be based on the experience gained in each
application. Inspection of wetted components is
recommended at least once per year or any time
that one of the following conditions occurs:
• Excessive pressure drop is encountered at a
known flow rate.
• A flame front is detected.
Maintenance is accomplished by removing the
element assembly for inspection and cleaning or
replacement.
CAUTION
The connecting pipeline must be free of all hazardous
or flammable vapors before inspection procedures
begin. Before disassembling arrester consult M aterial
Safety Data Sheets (MSDS) for all products that the
arrester was exposed to in service. The components
should be cleaned according to MSDS procedure.
Take appropriate safety precautions regarding eye
protection, skin contact & respiration.
1. When removing the element housing for
maintenance, support the weight by attachment
to the housing handles, or lifting eyes, and
proceed as follows.
WARNING
Handles or lifting eyes on the element
housing are to be used for handling the
housing only during inspection and
maintenance. DO NOT use these eyes to lift
the entire detonation flame arrester assembly.
2. Loosen the hex nuts and remove only those
studs or tie rods necessary to withdraw the
housing.
3. On the remaining studs, loosen the holding nuts
and use the spreader bolts to separate the base
halves from the housing. Use spacer blocks or
spreader tools, if necessary, to safely secure
the base halves so the housing is free for
removal. The remaining studs will support and
position the housing.
In a horizontal line, the flame bank assembly
should be supported before removing the
studs. Use structures and equipment suitable
for supporting the components weight. The
weight is noted on the drawing later in this
manual.
4. Remove the housing assembly for inspection.
The flame element and supporting grids shall
be visually inspected for damage or corrosion
build-up from both sides. If the flame element
appears to be damaged, it should be replaced
immediately with a new one.
5. Inspect the surfaces of the element for
corrosion or foreign material that appears to
restricting the passageways. If the flame
element is plugged it can be cleaned by one of
the following methods:
• Compressed air.
• High pressure steam or water purge.
• Solvent wash followed by compressed air.
• Wire brush cleaning the element surface.
6. Inspect the sealing gasket for damage and
replace if necessary.
7. Reassemble the housing, elements and
gaskets. Tape the gaskets to the housing with
a thin tape, such as masking tape. Then insert
the housing assembly between the base
flanges.
The studs will position the housing on the base
centerline. Insert the studs and torque all
fasteners to half the value listed in Table 2 in a
staggered, alternating pattern to provide an
evenly compressed gasket joint.
Lubricate all studs and nuts with an appropriate
thread lubricant. If the arrester will see high
temperature service or stainless steel fasteners
are used, select an anti-seize compound such
as moly-disulfide.
8. Make up the final torque and check that no
further nut rotation occurs at the specified torque
value. The torque values are based on original
gaskets supplied by Groth Corporation.
be
4
IOM-7758A
Ref. ID 97895
acrylonitrile
0.87
0.034
ammonia
3.17
0.125
amyl acetate
0.99
0.039
butane
0.98
0.039
butyl acetate
1.02
0.040
butyl alcohol
0.94
0.037
carbon monoxide
0.94
0.037
cyclohexane
0.94
0.037
decane
1.02
0.040
ethane
0.91
0.036
ethyl acetate
0.99
0.039
ethyl nitrite
0.96
0.038
hexane
0.93
0.037
isooctane
1.04
0.041
isopentane
0.98
0.039
isopropyl alcohol
0.99
0.039
methyl alcohol
0.92
0.036
methyl ethyl ketone
0.92
0.036
pentane
0.93
0.037
propane
0.92
0.036
propyl acetate
1.04
0.041
vinyl acetate
0.94
0.037
vinyl chloride
0.99
0.039
Table 2
HOUSING
STUD TORQUE
CHART
Lb.Ft. (Nm)
Size
Torque
7/8”
190 [258]
1-1/8”
430 [584]
1-1/4”
600 [814]
The table below is a partial list of vapors for which the MESG has been measured and found to be greater than or equal to
0.025" [0.65 mm]. If your system contains a gas not listed in the table, please consult the factory.
Chemical Compound MESG*(mm) MESG (In)
acetone 1.02 0.040
acetonitrile 1.50 0.059
Chemical Compound MESG*(mm) MESG (In)
hydrogen cyanide 0.80 0.031
isobutyl alcohol 0.96 0.038
butadiene 0.79 0.031
butyne 0.71 0.028
carbon momoxide 0.91 0.036
dimethyl ether 0.84 0.033
ethylene 0.65 0.026
heptane 0.91 0.036
methane 1.14 0.045
methyl acetate 0.99 0.039
methyl isobutyl ketone 0.98 0.039
octane 0.94 0.037
propylene 0.91 0.036
propylene oxide 0.70 0.029
*Corrected MESG (mm), 100KpA, 20°C
5
IOM-7758A
Ref. ID 97895
MODEL NUMBER IDENTIFICATION
Z = Special
Z = Special Flanges
NOTES
Include model number when ordering.
For special options, consult factory
EXAMPLE: 7758A - 08 - 05 - 35 – FA
MODEL#
NOMINAL
SIZE
ELEMENT
SIZE
MATERIAL
OPTIONS
O = No Options
7758A
Indicates a 8” Model 7758A with 5” Element Size, Carbon Steel Body, 316 SS Flame Element, 150# Flanged Outlet, ATEX Integrated Temp Sensor
08”
10”
12”
20”
Thru
30”
Flame Element Winding
Body Material
3 = Carbon Steel
5 = 316 SS
A = ATEX T/C
Z = Special
F = 150# A.N.S.I.
Flange
PRODUCT LIMITED WARRANTY
A. Seller warrants that products which are manufactured by Seller, are
manufactured in accordance with published specifications and free
from defects in materials and/or workmanship for a period of (12)
twelve months. Seller, at its option, will repair or replace any
products returned intact to the factory, transportation charges prepaid,
which Seller, upon inspection, shall determine to be defective in
material and/or workmanship. The foregoing shall constitute the sole
remedy for any breach of Seller's warranty.
B. THERE ARE NO UNDERSTANDINGS, AGREEMENTS,
REPRESENTATIONS, OR WARRANTIES, EXPRESS OR
IMPLIED, (INCLUDING MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE REGARDING PRODUCTS)
UNLESS SPECIFIED IN THE SALES CONTRACT. THIS
CONTRACT STATES THE ENTIRE OBLIGATION OF SELLER.
Seller makes no warranties, either express or implied, except as
provided herein, including without limitation thereof, warranties as to
marketability, merchantability, for a particular purpose or use, or
against infringement of any patent of products. In no event shall
Seller be liable for any direct, incidental or consequential d amages of
any nature, or losses or expenses resulting from any defective new
product or the use of any such product, including any damages for
loss of time, inconvenience, or loss of use of any such product.
C. The original Manufacturer shall be solely responsible for the des ign,
development, supply, production, and performance of its products
hereunder, and the protection of its trade name or names, if any. It
assumes no responsibility, for products modified or changed in any
way by its agent or customer. Any such modifications or changes to
products sold by Seller hereunder shall make the product limited
warranty null and void.
D. The Manufacturer shall be under no obligation to manufacture, sell,
or supply, or to continue to manufacture, sell or supply any of the
Products.
7
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