Watson-Marlow 505LA User Manual
WATSON-MARLOW MANUALS
m-atex505la-gb-03: PB0379-2
ATEX Directive (94/9/EC) and
Watson-Marlow’s 505LA, 505LXA and
505LGA pumpheads
Contents
Page Page
1 Introduction 1
2 Pumphead types 2
3 Hazardous environments 2
4 Operating parameters 3
5 Potential pump hazards 4
6 Installation guidelines 4
7 Tube life 5
8 Tubing materials in
ATEX applications 6
9 Servicing and cleaning
requirements 7
10 Materials of construction 8
11 Summary of modifications 9
12 ATEX marking 10
13 Replacements 10
14 Manufacturer’s Declarations 11
1 Introduction
Directive 94/9/EC, commonly known as the ATEX directive, carries obligations to
the person who places equipment on the market, in the EU territory, for use in
potentially explosive environments. A number of pumps manufactured by WatsonMarlow are suitable for use in hazardous environments; ATEX compliant pumps from
the 505LA series are listed below, in Section 2 Pump models.
Watson-Marlow’s 500 series ATEX pumps have been rated as Group II, Category
2G IIB c T4 equipment for use in gas based environments only. The pumpheads
are sold individually (for use with customer specified ATEX drives) and in defined
configurations complete with ATEX drives.
This document provides specific ATEX information and should be used in
conjunction with the original 505L user manual (m-505l-gb-01).
ATEX Directive: Watson-Marlow 505LA, 505LXA and 505LGA pumpheads User Manual 1
2 Pumphead types
The following 500 series pumpheads are covered by this manual:
505LA ATEX pumpheads
505LA* 053.4001.A00 505LA ATEX pumphead
505LXA* 053.4011.A00 505LXA ATEX pumphead
505LGA* 053.4010.A0G 505LGA ATEX pumphead
The following 500 series pumps are also ATEX-compliant but are dealt with in a
separate document (m-atex501rla-gb-05: PB0346).
501RLA ATEX pumpheads
501RLA* 053.0001.A00 Twin roller for 1.6mm wall thickness tubing
501RL2A* 053.0001.A20 Twin roller for 2.4mm wall thickness tubing
501RLGA* 053.0011.A0G Twin roller for 1.6mm wall Sta-Pure tubing
501RL2GA* 053.0011.A2G Twin roller for 2.4mm wall Sta-Pure tubing
501RLCA 053.0002.A00 Close-coupled for 1.6mm wall tubing
501RL2CA 053.0002.A20 Close-coupled for 2.4mm wall tubing
501RLCGA 053.0022.A0G Close-coupled for 1.6mm wall Sta-Pure
501RL2CGA 053.0022.A2G Close-coupled for 2.4mm wall Sta-Pure
* NB: these pumpheads are compatible with a number of Watson-Marlow cased
drives. However, the Watson-Marlow cased drives are not ATEX compliant and must
not be used in hazardous locations.
Any 500 series pumpheads not listed above are NOT suitable for use in
hazardous environments (at date of issue).
3 Hazardous environments
All of Watson-Marlow’s ATEX pumps are classified as Group II, Category 2G IIB c T4
equipment under the definitions of 94/9/EC:
“Group II, Category 2 products should be designed to be capable of remaining within
their operational parameters, as stated in the instruction manual, and based on a
high level of protection for their intended use, in areas in which explosive atmospheres caused by mixtures of air and gases, vapours, mists or air/dust mixtures”
(see page 1) “are likely to occur.”
Furthermore, “The explosion protection relating to this category must function in
such a way as to provide a sufficient level of safety even in the event of equipment
with operating faults or in dangerous operating conditions which normally have to
be taken into account”.
Watson-Marlow pumps must not be used in the underground parts of mines,
and in surface installations of such mines, likely to become endangered by
firedamp and/or combustible dust.
NB: where two or more items of ATEX equipment are combined, the complete
assembly shall carry the rating of the lowest ranking individual piece of equipment.
ATEX Directive: Watson-Marlow 505LA, 505LXA and 505LGA pumpheads User Manual 2
4 Operating parameters
The following tube materials can be used with the 505LA pumpheads in double “Y”
or continuous tubing configurations (two separate channels). Bore sizes range from
0.5mm to 9.6mm, with 2.4mm wall thickness. Only Watson-Marlow tubing should
be used to guarantee continued compliance with the ATEX directive.
Tubing: working temperature range
Marprene 5C to 80C
Bioprene 5C to 80C
Pumpsil -20C to 80C
STA-PURE PCS 0C to 80C
STA-PURE PFL 0C to 80C
Neoprene 0C to 80C
PVC 0C to 80C
The following parameters define the boundary of the safe working envelope - these
values must not be exceeded (ATEX compliance will be invalidated):
505LA pumpheads
Operational temperature range -20C to 80C
Max peak pressure 2 bar *
Max continuous speed 350 rpm
Corrosion resistance
Tube life See 7 Tube life
Torque limit (drive coupling) 2.2Nm
See 9 Materials of
construction
* Please note that, although Sta-Pure tubing is rated at 4 bar in a standard 505LG
pumphead, the ATEX version (505LGA) is limited to 2 bar.
WARNING! Do not run dry for excessive periods. Roller and tubing
temperatures can exceed normal operating range.
WARNING! Do not run pumphead against a dead-end condition (closed
discharge). This can lead to excessive roller and tubing temperatures
and pressures in excess of the limits in the table above.
When two or more items of ATEX equipment are combined, the permissible operating envelope will be determined by the narrowest range after considering all values
for a given parameter.
ATEX Directive: Watson-Marlow 505LA, 505LXA and 505LGA pumpheads User Manual 3
5 Potential pump hazards
As part of the requirements of 94/9/EC all potential hazards, including expected
malfunctions, have been identified and subjected to a risk assessment. In order
to prevent these ignition sources becoming effective a number of changes have
been implemented (see Section 10). In addition to engineering modifications, the
changes include additional operating instructions in order to specify correct usage in
hazardous locations. Please refer to Sections 6-10 for further details.
Recognised ignition sources
Surface temperatures of rollers and tubing
Tube burst and subsequent spilling of pumped fluid
Mechanical failure of rotor hub
Exothermic and pyrophoric chemical reactions
Electrostatic charging of tubing and fluid
Bearing failure
Spring failure
6 Installation guidelines
Please refer to the standard 505L manual (m-505l-gb-01) for general installation
instructions.
It is recommended that the chosen ATEX drive (motor/gearbox) is configured to
safely reach an overload condition before the 2.2Nm torque limit is reached. This
will prevent catastrophic failure of the rotor in the rare occurrence of a major
obstruction.
Particular attention should be given to the “Do’s and do not’s” section regarding
interfacing with suction and discharge tubing and/or pipework. It is important to
ensure proper connections are made to prevent leaks.
All ATEX pumpheads include provision for the prevention and dissipation of electrostatic charge. In order to dissipate electrostatic charge effectively there must be
sufficient electrical contact between the pumphead and the suitably earthed drive.
It is imperative that the 505LA pumpheads are earthed by connecting the
earth terminal (circled in the photograph below) to earth (usually via a
suitable point on the pump drive).
It is possible to check the effectiveness
of any earth connection by measuring
its electrical resistance. To ensure
reliable dissipation of static the
maximum resistance to earth
should not exceed 1 MOhm.
Peristaltic tubing has limited
conductivity and so its use should
be limited to the length adjacent to
the pumphead. Electrostatic testing
and length of tubing limitations
have been used to determine that
Watson-Marlow tubing is compliant
with a II 2G IIB c T4 rating. Earthed,
conductive pipework should be used
elsewhere in the system.
ATEX Directive: Watson-Marlow 505LA, 505LXA and 505LGA pumpheads User Manual 4
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