WATER INDUSTRY
MAINTENANCE WORKING GROUP
PREVENTIVE MAINTENANCE SPECIFICATION (PMS)
SUMMARY 03
MEMBRANE TREATMENT EQUIPMENT
ISSUE 1
NOVEMBER 2012
Copyright  2012, ESR Technology. All rights reserved. No part of this document, may be reproduced in any
form, electronic or mechanical, including photocopying, recording or any other information storage and
retrieval system, without permission in writing from the Pump Centre.
The Pump Centre is a Centre of Excellence within ESR Technology, one
of the UK’s leading engineering, safety and risk consultancies. ESR
Technology provides independent technical expertise to help its
customers ensure asset integrity, improve machine reliability, manage
safety and risk and transfer best practice.
WATER INDUSTRY
MAINTENANCE WORKING GROUP
PREVENTIVE MAINTENANCE SPECIFICATION SUMMARY 03
MEMBRANE TREATMENT EQUIPMENT
Prepared by:
M Craven
R Marlow
Pump Centre
Pump Centre
With technical support and co-operation from the Water Industry Maintenance
Working Group (WIMWG) consisting of:
K Martin
C Hampshire
M Phipps
N Garnett
K Solts
A Cross
A Hastie
A Atkinson
T Quinn
P Richardson
R White
M Ison
D Olatunde
R Edwards
D White
S Crouchley
D Appleyard
K Plumb
Affinity Water
Bristol Water
Dwr Cymru
Environment Agency
Essex & Suffolk Water
NI Water
Northumbrian Water
Scottish Water
South West Water
Southern Water
Thames Water
United Utilities
Yorkshire Water
Please Note
This document may be reviewed and re-issued periodically to take account of
changes to maintenance practices.
PMS SUMMARY 03
CONTENTS
INTRODUCTION
AFFINITY WATER
BRISTOL WATER
THAMES WATER
UNITED UTILITIES
YORKSHIRE WATER
ISSUE 1
NOVEMBER 2012
PMS SUMMARY 03
INTRODUCTION
This preventive maintenance specification (PMS) summary comprises a collection of
preventive maintenance specifications from the following WIMWG members:
a)
b)
c)
d)
e)
Affinity Water;
Bristol Water;
Thames Water;
United Utilities; and
Yorkshire Water
Where a WIMWG member has not contributed PMSs to this summary, it should generally be
inferred that the member:
a) Does not operate/maintain a significant number of assets of this type;
b) Has contracted-out preventive maintenance for this asset; or
c) Does not implement a preventive maintenance regime for this asset.
It should be noted that some of the PMSs include routine preventive maintenance (RPM)
tasks (typically performed by operations staff), while others do not. Where RPM tasks are
not included in a given specification, it does not necessarily mean that these tasks are not
performed on the asset. In some cases, RPM tasks are not detailed in a specific document
relating to the asset, but are included in a higher level, more generic maintenance
specification. Any queries regarding RPM should be addressed to the WIMWG member in
question.
ISSUE 1
NOVEMBER 2012
PMS SUMMARY 03
AFFINITY WATER
ISSUE 1
NOVEMBER 2012
PMS SUMMARY 03
BRISTOL WATER
ISSUE 1
NOVEMBER 2012
PMS SUMMARY 03
THAMES WATER
ISSUE 1
NOVEMBER 2012
System /
Equipment
General
OMP
Site
Status
Membrane Filter
Generic
Operational
Title
Operation and Maintenance Plan
Task
No
1
1
week
1
mth
Minimum
Skilled
Resource
24
mth
36
mth
84
mth
All Trades
All Trades
All Trades
All Trades
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Ops
Filter Set: Service contract to filter set. Conduct process audits. Maintain filter modules, repair or replace modules. Update quality control database.
37
38
39
40
41
42
43
44
49
50
51
52
53
54
55
56
57
58
59
60
Valve Actuator (Pneumatic) All valves on filter set. Exercise to open and closed position ensuring correct operation.
Lubricate all designated points with recommended lubricant. Check oil levels and top up or replace as necessary.
Check gland packing / seal, adjust as required or raise follow up job.
Valve Actuator (Electric) All valves on filter set. Exercise to open and closed position ensuring correct operation.
Check security of cable bushses & glands and local isolator.
Check oil levels in gearbox and top up or replace as necessary.
Check gland packing / seal, adjust as required or raise follow up job.
If display reads "BATTERY LOW" or "BATTERY FLAT", replace battery following detailed manufacturers' instructions or raise follow up job.
Pressure Measurement - All items on filter set. Inspect transmitter and power supply for signs of damage / overheating, check security of glands
and cable connections.
Check all connections & fuses for condition / tigtness and rating.
Check pipes and transducer isolating valves.
Carry out full calibration of unit against a measured pressure or using a standard test instrument. Record values before and after calibration and
note errors.
Check operation of remote / local alarms and indication on SCADA.
Flow Measurement Ensure meter and cleaning unit (where fitted) are secure and there is no external damage.
Inspect cable connections and circuit boards for damage/overheating/water ingress.
Check meter memory contents are correct where applicable. Record and log.
Using meter built in test facilities, check calibration.
Check output signal to secondary instruments and telemetry are correct.
Where possible, isolate flow through meter and check that it reads zero.
Check operation of cleaning unit where applicable.
Return meter back into service.
Where possible check against second flow meter - Record error.
Attach calibration label. Label must state - 'Calibrated by', 'When Calibrated' and 'Next due date'.
Compressors: Service contract to compressors
61
Membrane Modules Full replacement of modules by filter set stack (7 year replacement schedule).
62
63
64
65
66
67
68
69
70
71
72
73
74
75
Compressors: Maintenance to follow existing corporate standards
Pressure Vessels: Maintenance to follow existing corporate standards
Pumps: Maintenance to follow existing corporate standards
Safety Showers: Maintenance to follow existing corporate standards
Sampling Equipment: Maintenance to follow existing corporate standards
Blowers: Maintenance to follow existing corporate standards
Chemical Dosing: Maintenance to follow existing corporate standards
Tank: Maintenance to follow existing corporate standards
Valves: Maintenance to follow existing corporate standards
Starters: Maintenance to follow existing corporate standards
Level Measurement: Maintenance to follow existing corporate standards
Pressure Measurement: Maintenance to follow existing corporate standards
Temperature Measurement: Maintenance to follow existing corporate standards
Flow Measurement: Maintenance to follow existing corporate standards
76
Test run to check unit runs consistently & smoothly and is free from any leakage. Ensure correct operation of unit in: local, remote, auto mode and
check all emergency stops are working correctly.
All Trades
77
Comply with Standard Instructions IEMT000 as applicable.
All Trades
1
day
1
week
1
mth
3
mth
6
mth
12
mth
24
mth
36
mth
84
mth
Resource
18
12
15
16
19
7
150
150
46
47
48
General
1
day
Major Maint
36
45
Major
Service
Generic
Equipment
Comply with Standard Instructions IEMT000 as applicable.
Minor
Maintenance
3
6
12
mth mth mth
35
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Minor
Service
Basic Care
Visually check unit and its associated equipment for security and free from excessive noise, vibration or overheating and there is no external
damage, leaks, missing fixings and all guards are secure and in good condition.
Assess frequency of service is correct.
Raise notification for any required follow up maintenance. Record condition of asset condition (Between Excellent and Unsatisfactory).
Check SCADA / HMI / Control panels to ensure all alarms are recorded and where necessary reported.
Check rate of flow change is steady and does not exceed the maximum rate set down in SOM.
Check the feed flow rate is within the specified range for the number of units / stacks in operation
Check individual stack flow is within design limits and not above maximum
Check combined feed turbidity reading is within defined range
Check combined feed pH reading is within defined range
Check combined feed conductivity reading is within defined range
Check combined filtrate turbidity reading is within range
Check combined filtrate conductivity reading is within range
Check combined filtrate pH reading is within range
Check backwash time is correct according to programme settings
Check individual stack dirty backwash water pH is within range for efficient wash water treatment conductivity
Check membrane integrity pdt (pressure decay test) value is within limits set
Check filtrate pH reading is within range
Check filtrate turbidity reading is within range
Visually check instruments are operating and clean
Bench test water softener, soften water solution for hardness
Bench test cl2 inlet monitor, adjust as necessary
Ensure shower and eye washing facilities are fully operational.
Check all instrument calibration stickers are in date
Manually check operation of ventilation system.
Air receivers - Drain any moisture from receivers
Check integrity of plant (e.g. units, pumps, pipe work, chemical housing integrity, bunding, unusual noises, etc)
Check operation of compressors
Archive data
Check operation of pre screens
Check filter for operation of all valves and actuators, report any issues found.
Check backwash system.
Check operation of basement sump pump.
Chemical Dosing - Check for leaks on pumps & in cabinet, clean floor. Check storage tank and bund for spillage. Listen for leaks on system. Top up
dash pots
Check water softener operation, storage of salt and record flows.
2
Operations
Standards
Task Description
Ops
External
T1
T1
T1
T1
T1
T1
T1
T1
T2E
T2E
T2E
T1I
T1I
T2E
T2E
T2E
T1I
T1I
T2E
T2E
T2E
T2E
T2E
External
T1
T1
T1
T1
T1/T3E
T1
T1/T2M
T1/T2E
T1
T2E
T3E
T3E
T3E
T3E
Number of Tasks
8
22
17
Estimated time in minutes / person
Ops 2
20
20
T1
T2M
T2E
T1I
T4I
CBC
Man-hours 0.033 0.333 0.333
30
0.5
2.5
2.5
160
200
180
90
6
4.5
External
0
Ops
T1
T2M
T2E
T1I
T4I
CBC
All
PMS SUMMARY 03
UNITED UTILITIES
ISSUE 1
NOVEMBER 2012
Task Description
Filter - Membrane
Filtration Process Membrane
Inspect vibration dampers for leaks, cracks & evidence of corrosion. If faulty, raise a work order for
refurbishment.
Inspect membrane exterior tube/valves/pipework for leaks, cracks & evidence of corrosion. If faulty, raise a
work order for refurbishment.
Skill
Frequency
O
O
Perform pressure decay test and record results. If less than 4.1, carry out sonic test to isolate and raise a work
order.
Check for broken fibres in modules and repair if necessary (Pinning).
O
O
1
Perform pressure decay test and record results. If less than 4.1, carry out sonic test to isolate and raise a work
order.
Carry out Human Senses Tour of all process related equipment, checking for unusual occurrences and failure.
Log any excessive signs of Vibration, Heat, Noise, Smell, Leakage, Power and Pressure. If further work
required raise work order for repair.
O
91
O
1
Verify Chemical usage.
O
7
TO
28
Review Process Performance on MCC or SCADA, investigate all alarms. If further work required raise work
order for Ops/Maintenance.
O
1
Arrange for annual rig inspection.
O
364
CIP Chemical strength tests. If faulty raise a proactive work order for repair.
PMS SUMMARY 03
YORKSHIRE WATER
ISSUE 1
NOVEMBER 2012
Where a vibration test indicates that there is a defective membrane housing, a bubble test
is used to check individual membrane elements. If the element is found to be damaged, it
needs to be repaired. This procedure describes how to carry out a bubble test and to
repair an element.
Applies to all water treatment works where membrane filters are installed.
Materials Needed:
•
•
•
•
•
•
A test basin with special connectors and threaded rods;
Air Pressure Regulator;
Tools for removing the end-caps;
Disposable bags;
Special Clothing;
Sodium Hypochlorite.
Method
When the permeate side of the membrane elements are pressurised, it is only possible for
air to reach the feed side if there is a compromised membrane filter. This is because with
low air pressure and water at the feed side, no air will diffuse through the membrane layer.
The air bubbles escaping from a fibre will prove the presence of a compromised
membrane filter.
Procedure
Introduction
The compromised membrane filters will be easily observed by continuous air escaping.
These compromised membrane filters shall be plugged following the membrane element
repair procedure.
Procedure
1. Flush the test basin with water.
2. Prepare the test basin by filling it with water (with 20 ppm Sodium Hypochlorite).
3. Open the membrane housing at both sides and keep the end-caps with piping in
disposable bags, leave the end-connector in the end-cap. Avoid damage to end
connector. Be alert when the end-caps are removed because water will be released
from the membrane housing.
4. Wash hands and put protective clothing on (disposable latex or nitrile gloves and
disposable paper suit with hood).
5. Take a membrane element out of the front side of the membrane housing, remove the
inter connectors and submerge the membrane element in the test basin. NB: The
membrane elements should be lifted by 2 people.
6. Place blind connector at one side of the central piping of the membrane element and
place other connector, with the air connection at the other side. Keep the connectors in
place by using the 1.8 metre threaded rods and metal end-plates.
7. Connect the connector with air connection to an air supply and slowly pressurise the
permeate side to 0.5 bar by slowly opening the air pressure regulator (max. is 1 bar).
8. Entrapped air will escape as air bubbles, for approximately 2 minutes from inside of
the capillaries.
9. A constant flow of air bubbles, more than 2 bubbles per second escaping from a
capillary will indicate a defected membrane. Less than 2 bubbles per minute indicates
air diffusion.
10. The membrane element should be repaired, when needed, according to the
membrane element repair procedure and re-tested.
11. The membrane elements need to be tested in sequence. When a membrane element
is tested it has to be reinserted at the back of the membrane housings. This way, the
next membrane element can be pushed out and at the end of the test all membrane
elements are in their original position. In order to avoid heavy lifting, the membrane
element has to be drained when it is taken out of the test basin. Do not forget to
reconnect the elements with inter connectors.
12. Continue testing until all 4 elements are tested as in point 5.
13. After all membrane elements are tested, the basin should be emptied and flushed with
water.
14. The tested/repaired membrane elements are reinserted in the membrane housing and
the rack should be started up according to the reinstallation start up procedure.
The membrane element repair has to take place in the test basin. Epoxy plugs are used to
plug the membrane fibres where the air escapes.
Materials
•
•
•
•
Test Basin from bubble test
Hammer
Repair Pins
Cutting Tongs
Procedure
The membrane element repair takes place in the test basin, because the defected
capillaries have to be detected by the bubbles.
1.
2.
3.
4.
Gently press a repair pin on both sides of the defective capillary.
Repeat this procedure until all leaking capillaries are plugged.
Cut the repair pins until 2-3 mm above the surface.
Hammer repair pins until level with surface.
NB: All materials used for the repair must be disinfected; hammering the repair pin too far
will cause damage to the epoxy.