Emerson Marston Series Quick guide

© 2017 Emerson. All rights reserved.Emerson.com/FinalControl VCOSI-01897-EN 16/01
MARSTON MAS MAGNETIC ALARM SENSORS
OPERATING AND SAFETY INSTRUCTIONS (ATEX)
Additional safety instructions for valves and accessories being used in a potentially explosive atmosphere under
ATEX 94/9/EC. Before installing any MAS sensor, these instructions must be read fully and understood
REFERENCE
A Declaration of Conformity - ATEX MAS3
has been issued which outlines the relevant
conformity of the ATEX directive.
See also: Emerson.com/FinalControl
MARKING
The certificate number is: Baseefa03ATEX0606.
The device is considered to meet the explosion
protection level: II 1GD 85°C.
STORAGE
The MAS magnet will always be connected
to the bursting disc. The magnet provides a
strong magnetic field. The bursting disc may be
fragile when designed to offer protection for low
pressures. Extreme care must be taken to ensure
that a bursting disc assembly fitted with a magnet
is not placed near a magnetic surface during
storage or during installation. The MAS magnet is
considered to have an indefinite storage life when
protected from magnetic surfaces.
IDENTIFICATION
All bursting discs fitted with the MAS magnet
are supplied with an identification label. This
label identifies the unique equipment number,
tag number where relevant, size and particular
operational details. These must be checked
against the application requirements before
installation to ensure a safe and satisfactory
installation. Read all warning labels before
carrying out any operation.
DIRECTIVES
This design of the Marston burst disc indicator
device has been examined and certified by our
notified body, Baseefa, with respect to the ATEX
directive 94/9/EC. The device conforms to the
essential Health & Safety requirements for
use in hazardous areas identified in Annex II,
provided that it is installed as directed within
the attached Installation and Maintenance
Instructions.
INSTALLATION
WARNING
For safety reasons, it is important that the
following advice is noted:
1. Bursting discs to which MAS magnets have
been fitted will continue to discharge until
pressure has equalized.
2. The discharge may include parts of the
bursting disc.
3. The discharged products must be vented to a
safe place.
4. Extreme noise levels may occur.
5. The blast may be severe and reaction forces
will be imposed.
6. MAS sensors are connected to the alarm
system via a suitable switch barrier.
7. The service life of a bursting disc / MAS
magnet cannot be guaranteed.
8. The MAS sensor constitutes a normally closed
(NC) circuit.
9. Bursting disc devices that are fitted with MAS
sensor systems may be heavy.
10. Bursting discs fitted with MAS magnets may
be fragile.
11. Bursting discs may have sharp edges.
12. Misalignment or damage may result in a loss
of magnetic field
13. It is not recommended to re-use MAS
magnets.
14. Modification is not allowed, except by
Emerson.
15. Should the magnet carrier be damaged in
any way, magnetic particles may become
detached.

2
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Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.
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respective owners.
The contents of this publication are presented for informational purposes only, and while every effort 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 specifications of such products at any time without
notice.
Emerson.com/FinalControl
MARSTON MAS MAGNETIC ALARM SENSORS
OPERATING AND SAFETY INSTRUCTIONS (ATEX)
Read all warning labels fitted to the device
before operation or maintenance
MAINTENANCE
Burst disc indicators type MAS normally
are considered to be maintenance-free, as
they have no moving parts. However, it is
recommended that they are checked regularly
during service to ensure there are no signs of
corrosion or damage. This should be done most
frequently when commissioning the equipment.
A regular service inspection period should
be determined for each MAS system as each
application is different.
DISPOSAL
Items should be disposed of after use in
accordance with local and national regulations.
ASSEMBLY
The MAS magnet attached to the bursting
disc provides a strong magnetic field. The
bursting disc may be fragile when designed
to offer protection for low pressures. Extreme
care must be taken to ensure that a bursting
disc assembly fitted with a MAS magnet is
not placed near any magnetic surface during
storage or during installation into the holder.
Normal installation procedures for the
particular bursting disc device should be
followed. This will ensure that the magnet
is placed in the correct position to trigger
the sensor when required. This position is
confirmed when the system is switched on and
shows the NC format required by the particular
alarm system.
After installation into the holder, care must be
taken not to allow the magnet to be placed near
to a magnetic surface before installation into
the plant.
To maintain conformity to the ATEX directive
and the certificate Baseefa03ATEX0606, the
input to the sensor should be limited to 100
mA max. The system then offers indication in
accordance with EEx ia IIC T6 (-20°C ≤ Ta ≤
75°C).