Groth 7758A User Manual

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 [phone]

Fax [phone]

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