WATSON-MARLOW MANUALS
m-atex505la-gb-03: PB0379-2
ATEX Directive (94/9/EC) and Watson-Marlow’s 505LA, 505LXA and 505LGA pumpheads
Contents
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Page |
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Page |
1 |
Introduction |
1 |
9 |
Servicing and cleaning |
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2 |
Pumphead types |
2 |
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requirements |
7 |
3 |
Hazardous environments |
2 |
10 |
Materials of construction |
8 |
4 |
Operating parameters |
3 |
11 |
Summary of modifications |
9 |
5 |
Potential pump hazards |
4 |
12 |
ATEX marking |
10 |
6 |
Installation guidelines |
4 |
13 |
Replacements |
10 |
7 |
Tube life |
5 |
14 |
Manufacturer’s Declarations |
11 |
8 |
Tubing materials in |
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ATEX applications |
6 |
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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 |
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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 |
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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 |
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Max peak pressure |
2 bar * |
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Max continuous speed |
350 rpm |
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Corrosion resistance |
See 9 Materials of |
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construction |
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Tube life |
See 7 Tube life |
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Torque limit (drive coupling) |
2.2Nm |
* 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 |
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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 |
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