Watson Marlow Pumps 800 Series User manual

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 1
WATSON-MARLOW BREDEL MANUALS
ATEX Directive (94/9/EC) and
Watson-Marlow’s 800 series
pumps and pumpheads
m-atex800-gb-01: PB0356
1 Introduction 1
2 Pump models 2
3 Hazardous environments 2
4 Operating parameters 3
5 Potential pump hazards 4
6 Installation guidelines 4
7 Tube life 5
8 Servicing and cleaning
requirements 6
9 Materials of construction 7
10 Summary of modifications 8
11 ATEX marking 9
12 Replacements 9
13 Manufacturer’s Declaration 10
Contents
Page Page
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 Watson-
Marlow Bredel are suitable for use in hazardous environments; ATEX compliant pumps
from the 800 series are listed in Section 2 Pump models.
Watson-Marlow’s 800 series ATEX pumps have been rated as Group II, Category 2
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 Watson-Marlow ATEX drives.
This document provides specific ATEX information and must be used in
conjunction with the original 825/840 user manual (800-gb-01.pdf).

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 2
2. Pump models
800 series ATEX pumps and pumpheads are quoted on application by Watson-
Marlow’s applications engineering department. Part codes may vary depending on
the final build specification and the customer.
Watson-Marlow cased drives are not ATEX-compliant and must not be used
in hazardous locations.
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.
3. Hazardous environments
When used in accordance with the operating guidelines defined in this manual,
Watson-Marlow’s ATEX pumps are classified as Group II, Category 2 equipment for
gas-based environments, 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
are likely to occur.”
Watson-Marlow’s ATEX pumps are rated for use in gas-based atmospheres
only, and must not be used in hazardous dust environments.
94/9/EC also states, “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’s ATEX pumps have been designed to cope with potential
ignition sources during normal operation and following expected
malfunctions. EN standards have been used to apply ignition-protection
concepts to prevent potential ignition sources becoming effective.
The Equipment Group II rating means 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.
For further information on the correlation between ATEX zones and ATEX equipment,
please refer to the Workplace Directive (1999/92/EC).

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 3
4. Operating parameters
Watson-Marlow’s standard ATEX rating (equipment group IIB) can only be
achieved when 800 series pumps are used with Bioprene tubing. This is
available in 25mm and 40mm bore sizes, with wall thicknesses respectively
of 9.0mm and 12.8mm.
Electronic testing (to EN13463-1: 2001(E) annex C) has determined that the use of
STA-PURE tubing limits the 800 series ATEX rating to equipment group IIA. Please
contact Watson-Marlow for further information.
Only Watson-Marlow tubing should be used to guarantee continued compliance with
the ATEX directive.
Tubing: working temperature range of fluid
Bioprene 5C to 40C (standard group IIB rating)
STA-PURE 0C to 40C (limited to group IIA)
The following parameters define the boundary of the safe working envelope—these
values must not be exceeded (ATEX compliance will be invalidated):
800 series ATEX pumps
Operational
temperature range -20C to 40C ambient
Max peak pressure 3.5 bar
WARNING! Do not run pumphead
against a dead-end condition (closed
discharge). This can lead to
excessive pressure, which could
cause tube failure or component
temperatures in excess of the 135C
limit for the T4 rating
Max continuous speed 100 rpm
Corrosion resistance See 9 Materials of construction
Tube life See 7 Tube life
Torque limit 135Nm
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.
Appropriate pressure-protection must be designed into the system to protect against
blockages. This could be achieved by using equipment such as pressure-relief valves
or monitoring pressure levels and controlling the power supply to the pump.
WARNING! Do not run dry for excessive periods. Roller and tubing
temperatures can exceed normal operating range.

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 4
6. Installation guidelines
Please refer to the standard 800 series manual (800-gb-01.pdf) for general
installation instructions.
All ATEX pumpheads include provision for the prevention and dissipation of
electrostatic charge. In order to dissipate electrostatic charge effectively there must
be sufficent electrical contact between the pumphead and the suitably earthed drive.
It is imperative that the 800 series pumpheads are earthed by connecting
the earth terminals (seen in the photograph below) to earth (usually via a
suitable point on the pump drive, as seen here).
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 specifiy 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
Mechanical impact following incorrect maintenance
Exothermic and pyrophoric chemical reactions
Electrostatic charging of tubing and fluid
Bearing failure
Spring failure
It is possible to check the effective-
ness of any earth connection by
measuring its electrical resistance.
The resistance from any point on the
guard to the earth terminal is
typically 25 Ohms. To ensure
reliable dissipation of static the
maximum resistance to earth
should not exceed 1 MOhm.
It is also imperative that appropriate
over-pressure protection is designed
into the installation of the pump. This
will ensure that the safe operating
limits of the pump are not exceeded
in the event of a blockage.
Peristaltic tubing has limited conductivity and so its use should be limited to the length
adjacent to the pumphead.

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 5
Where there is potential for the pumped fluid to become charged through pumping,
protective measures should be implemented at the discharge outlet to dissipate this
charge safely.
It is recommended that the chosen ATEX drive (motor/gearbox) is configured to safely
reach an overload condition before the 135Nm torque limit is reached. This
will prevent catastrophic mechanical failure in the rare occurrence of a major
obstruction.
Note: Tube contact with polyamide materials such as nylon should be avoided.
7. Tube life
Only Watson-Marlow tubing should be used to guarantee continued compliance with
the ATEX directive.
A number of factors contribute to the life of the tubing:
Factors influencing tube life
Normal tube fatigue - dependent on tube size, material and
pumphead speed
Incorrect tube loading - see the 800 series manual
(800-gb-01.pdf) for guidance
Excess working pressure - see Section 4 Operating parameters
Chemical incompatibility - a table of tubing compatibility can be
found on http://www.watson-marlow.com/wmb-gb/p-chem-a.htm.
Immersion kits are available from Watson-Marlow for testing.
For each application it is strongly recommended that tube life should be determined
by trials, prior to installation in a hazardous environment. If this is not possible,
or if there is any doubt in terms of tube life then the following hazards should be
recognised before installing a pump in a potentially explosive atmosphere:
Chemical reaction between spilled pumped fluid and pump
materials - the materials of construction are listed in Section 9
Spilled, pumped fluid could be ignited by the surface temperature
of the rollers - Watson Marlow’s 800 series pumpheads have been
rated as T4 (meaning that even under worst-case operating
conditions the maximum surface temperature will not exceed
135C)
WARNING: The tube connectors are isolated metal parts and have no
path to earth via the pumphead. 800 series ATEX pumps are designed to
be connected into conductive metal piping systems, where static charge
on the tube connectors is dissipated via the pipe system earthing
arrangement. If the pump is used in a system with non-conductive pipes
or connections, the user will need to make provision for earthing the
tube connectors to ensure dissipation of any static charge.

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 6
8. Servicing and cleaning
requirements
Scheduled maintenance
The stainless steel rollers and roller shafts run on sealed bearings and do not require
lubrication. The bearings have a calculated life of 7,000 hours and should be replaced
at that time.
WARNING: The working surfaces of the rollers must be kept free from any
kind of lubricant. This is to prevent the rollers slipping against the tubing,
which can lead to local heating.
If fluid is spilled inside the pumphead, flush the pumphead out with water and mild
detergent as soon as possible. If specific cleaning agents are required to clean the
spillage, please consult the Watson-Marlow after-sales office before proceeding, in
order to confirm chemical compatibility. The same cleaning procedure should be used
to limit the build-up of dust (which can become electrostatically charged and/or
heated by friction).
Tube loading
800 series pumpheads use Watson-Marlow tube elements. Specific tube loading in-
structions are contained within the 825/840 operating manual which can be found on
the E-manuals CD supplied with each pumphead (CDR0600).
Important: Because of the importance of dissipating electrostatic charge the
earthing leads must be regularly checked for signs of corrosion.

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 7
9. Materials of construction:
800 series ATEX pumpheads
Description Part No, 825 Part No, 840 Material Finish
Track HFZ8013C Aluminium LM25TF paint
Door HF1264C HF1402C Aluminium LM25TF paint
Window HF1005S HF1005S PVC
Pin - hinge HF1007T HF1107T Stainless steel 303S31
Spacer - hinge pin HF1224T HF1224T Nylatron GS
Tube clamp, static HF1211T HF1411T Aluminium HE30
Tube clamp, dynamic HF1212T HF1412T Aluminium HE30
Pin - tube clamp HF1213T HF1413T Stainless steel 303S31
Insert - tube clamp HF1228T HF1428T Stainless steel 303S31
Rotor HF1203C HF1403C Aluminium LM25TF Paint
Plate - rotor clamp HF1244T HF1421T Stainless steel 303S31
Spacer - rocker HF1208T HF1408T Nylatron GS
Pin - rotor pivot HF1210T HF1410T Stainless steel 303S31
Spacer - pivot pin HF1225T HF1408T Nylatron GS
Spring - rotor torsion HF1237B HF1437B Stainless steel 302 AMS5688
Rocker HF1204C HF1404C Aluminium LM25TF paint
Plate - rocker side 1 HF1219S HF1419S Stainless steel 304S31
Plate - rocker side 2 HF1220S HF1424S Stainless steel 304S31
Spacer - rocker HF1223T HF1423T Stainless steel 303S31
Rollers HF1216T HF1416T Stainless steel 316S16
Bearing - ball BB0044 BB0047 Steel (1%C; 1.5%Cr)
Spindle - roller HF1217T HF1417T Stainless steel 316S16
Seal - shaft OS0038 OS0041 NBR/Stainless steel
Spring SG0013 SG0015 Stainless steel passivate
Pedestal - gearbox HF1242S HF1242S Stainless steel 304S11
Frame - support HF1271S
HF1272S
HF1467S
HF1468S Stainless steel 304S11
Switch - door
(ATEX rated) SWZ8002 SWZ8002
The above materials have been carefully selected and have a well proven track record.
However, if there are any aggressive chemicals present then it is imperative that a risk
assessment is conducted. This must not be limited to just the pumped fluid but should
also include any other aggressive fluids in the intended operating environment.

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 8
10. Summary of modifications
ATEX features of the 800 series pumpheads
Earth strap Earthing straps connect the door to the main
body of the pumphead and to the drive gearbox
ATEX label
This is a requirement of the Directive and includes
the ATEX rating for the pumphead (Group II Cate-
gory 2 for gas, T4)
ATEX manual This is an addendum to the existing manual
and includes ATEX-specific information
ATEX-rated door switch
Standard 825 and 840 pumps are supplied with
EExd switches. These are upgraded to ATEX for
the ATEX-compliant 800 series
Over-pressure protection
(not supplied)
The installation of appropriate pressure-relief
equipment is mandatory to avoid exceeding the
safe operating limits of the pump (following any
blockage)
The table below defines the modifications made to standard 825 and 840 pumpheads
for them to satisfy the requirements of the II 2 G, c IIB T4 ATEX rating:

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 9
11. ATEX marking
The 800 series ATEX pumpheads have been marked with the following labels:
12. Replacements
Spares and replacements should be ordered through Watson-Marlow Bredel Pumps or
through an offical representative. Only Watson-Marlow spares and replacements
should be used in order to guarentee continued compliance with the ATEX
Directive.
Watson-Marlow’s policy is to provide spare parts for all products for a minimum of
seven years from discontinuation. The ability to implement this policy is not
entirely within Watson-Marlow’s control and cannot be guaranteed, but every effort
will be made to honour this policy.
Watson-Marlow Bredel Pumps can be contacted at:
Watson-Marlow Bredel Pumps
Falmouth
Cornwall
TR11 4RU
England
Tel: [phone]
Fax: [phone]
Email: [email protected]
Web: www.watson-marlow.com

ATEX Directive: Watson-Marlow 800 series pumps and pumpheads User Manual 10
13. Manufacturer’s Declaration