Table Of Content0131976214_COVER.qxd 31/8/06 16:46 Page 1
SUITABLE FOR STUDENTS STUDYING THE PRACTICAL AND SSUUIITTAABBLLEE FFOORR SSTTUUDDEENNTTSS SSTTUUDDYYIINNGG TTHHEE PPRRAACCTTIICCAALL AANNDD
TECHNICAL ASPECTS OF NVQ PLUMBING LEVELS 2 & 3 TTEECCHHNNIICCAALL AASSPPEECCTTSS OOFF NNVVQQ PPLLUUMMBBIINNGG LLEEVVEELLSS 22 && 33
Blower
P
l
u
Plumbing: Mechanical Services is an essential guide for all
m
students who require a sound understanding of plumbing
principles and processes. This fifth edition includes the new
b
regulations relating to heat-raising appliances and updates on
i
relevant environmental issues. n
g
Key features: :
• includes new Building Regulations Part L1 and Part P M
• new material on environmental issues, including condensing
e
boilers and heat pumps
c
• updated material on sanitation and underground drainage h
• updated material on hot water supply and hot water heating a
n
systems, including zone control
i
• appendix updated to include current NVQ qualifications c
a
• new appendices on boiler sizing and central heating control
l
systems, both of which meet the recommendations of the
S
Building Regulations Part 6 and The Energy Saving Trust.
e
r
This book is a key course text for Plumbing NVQs Levels 2 & 3 and
v
Heating & Ventilation NVQs Levels 2 & 3, and is suitable for i
c
Technical Certificates in Plumbing levels 1 & 2. It is also essential
e
reading for those studying for the domestic heating course, gas,
s
oil, unvented hot water systems and lead sheet options connected
with these courses. Also suitable for students on professional
B
building courses where general aspects of plumbing are included. o
o
G. J. Blower has had many years' experience both as a plumber k
and as a teacher of plumbing. He was formerly Senior Lecturer in T
w
Plumbing at the College of North-East London as well as a City &
Guilds Examiner and an assessor for the London and South-East o
Regional Advisory Council.
FIFTH
ISBN 0-13-197621-4
EDITION
9 780131 976214
www.pearson-books.com
Plumbing:
Mechanical Services
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Plumbing:
Mechanical Services
Book 2
Fifth Edition
G.J. Blower
Eng Tech (CEI), MIP, LCGI, Technical Teachers Cert.
Formerly Senior Lecturer, Plumbing Mechanical
Services Section, College of North East London.
Currently an NVQ Visiting Assessor
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Pearson Education Limited
Edinburgh Gate
Harlow
Essex CM20 2JE
England
and Associated Companies throughout the world
Visit us on the World Wide Web at:
www.pearsoned.co.uk
First published 1984
Second edition published 1989
Third edition published 1996
Fourth edition published 2002
Fifth edition published 2007
© Macdonald & Evans Ltd 1984
© Pearson Education Limited 1989, 1996, 2002, 2007
The right of G.J. Blower to be identified as the author of this work has been asserted
by him in accordance with the Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without either the prior written permission of the
publisher or a licence permitting restricted copying in the United Kingdom issued by the
Copyright Licensing Agency Ltd, Saffron House, 6–10 Kirby Street, London EC1N 8TS.
All trademarks used herein are the property of their respective owners. The use of any
trademark in this text does not vest in the author or publisher any trademark ownership rights
in such trademarks, nor does the use of such trademarks imply any affiliation with or
endorsement of this book by such owners.
ISBN-13: 978-0-13-197621-4
ISBN-10: 0-13-197621-4
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
Library of Congress Cataloging-in-Publication Data
A catalogue record for this book is available from the Library of Congress
Typeset in 10/12pt Times by 35
Printed and bound in Malaysia
This publisher’s policy is to use paper manufactured from sustainable forests.
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Contents
Foreword viii Flame conduction and rectification 60
Preface to fifth edition ix Gas fires and back boiler units 63
Acknowledgements x Servicing gas appliances 71
Decommissioning 72
1 Welding and brazing processes 1 Further reading 72
Introduction 1 Self-testing questions 72
Welding safety 1
The flame 3 3 Cold water supply 74
Set-up of welded joints 4 The Water Regulations (1999) 74
Lead welding 5 Types of cold water supply 76
Defects in welds 7 Large water storage cisterns and
Lap welds on lead sheet 8 associated pipework 83
Angle seams 10 Noise in cold water systems 85
Lead-welded pipe joints 10 Pollution of water supplies 88
Bronze welding 10 Backflow prevention 92
Brazing processes 13 Non-mechanical backflow devices 93
Fusion welding low-carbon steel 17 Mechanical backflow protection 96
Further reading 17 Application of backflow-prevention
Self-testing questions 18 devices in domestic premises 100
Backflow protection in multi-storey
2 Gas installations 19 public and commercial buildings 104
Legislation 19 Sterilisation of cold water systems 107
Properties of natural gas 22 Provision for fire-fighting in buildings 107
Combustion and gas burners 22 Water treatment 114
Combustion air 23 Base exchange water softening 114
Installation of pipework 25 Hydraulic pressure testing 118
Gas meters 26 Decommissioning 120
Testing appliance pressures and Distribution pipe sizing in hot and
gas rates 27 cold water services 120
Pressure 27 Further reading 124
Gas pipe sizing 28 Self-testing questions 125
Testing for soundness 30
Purging domestic installations 33 4 Hot water supply 126
Ventilation 33 Corrosion and scale formation in
Flues 35 hot water systems 126
Flue terminals 43 Supplementary storage systems 127
Gas controls 47 High-level flow systems 127
Ignition devices 57 Dual boiler systems 128
Flame failure devices 57 Unvented hot water systems 130
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vi CONTENTS
Combination boilers 137 Types of oil burner 217
Pumped systems 140 Installation of oil-fired boilers 224
Storage vessels 140 Digital combustion analysers 230
Support and connections to Flues for oil boilers 230
horizontal hot storage vessels 142 Servicing oil-fired boilers 231
Towel rails 144 Further reading 232
Fuels used for hot water and Self-testing questions 233
central heating 146
Water heaters 147 7 Sanitary appliances 234
Electric water heating 148 Introduction 234
Introduction to solar heating 151 WC macerators 234
Heat pumps 155 Flushing troughs 236
Micro combined heat and power Ablutionary fittings 237
(micro CHP) 157 Anti-scald valves 239
Legionnaires’ disease 157 Showers 242
Further reading 157 Urinals 252
Self-testing questions 158 Disposal of chemical wastes 259
Hospital appliances (general) 260
Sanitary accommodation 260
5 Hot water heating systems 159
Washing and WC facilities for the
Space-heating systems 159
disabled 262
Heat emitters 160
Further reading 262
Central heating components 163
Self-testing questions 265
Boilers 166
Pipework systems used for heating 169
8 Sanitary pipework 266
Heating systems 171
Building Regulations relevant to
Mini-bore systems 174
sanitary pipework 266
Sealed heating systems 175
Standards relating to sanitary
Heating controls 178
pipework 267
Central heating design 186
Sanitary pipe sizes 268
Domestic heating calculators 189
Trap seal loss 268
Under-floor central heating 194
Ventilation of sanitary pipework 269
Commissioning and maintaining
Compression and its prevention 269
central heating systems 197
Modern pipework systems 269
Noise in hot water supply and
Branch positions in discharge stacks 274
heating systems 198
Ventilation of branch discharge pipes
Corrosion in heating systems and
to single appliances 275
its prevention 199
Ranges of appliances 276
Further reading 200
Special notes relating to
Self-testing questions 201
ventilating pipes 278
Access for cleaning and
6 Oil firing 202 maintenance 280
Fuel oils 202 Pipe ducts 280
Oil-fired boilers 202 Inspection and testing 281
Oil storage tank accessories 208 Maintenance 282
Tank overfill prevention 211 Further reading 283
Pipework systems for oil supply 213 Self-testing questions 284
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CONTENTS vii
9 Underground drainage materials, Mansard roofs 334
fittings and systems 285 Lead-welded details 335
Regulations relating to building Metal cladding of buildings
drainage 285 with preformed panels 340
Functions of drainage systems 285 Patenation oil 342
Health and safety 286 Inspection and maintenance of
Materials 286 sheet weatherings 343
Drainage fittings 286 Further reading 343
Support for above-ground drains 295 Self-testing questions 343
Flexibility 297
Bedding for underground drains 297 11 Electrical systems 345
Protection of drains near or above Regulations governing the
ground level or subject to installation of electrical supplies 345
imposed loads 298 Distribution of electricity 346
Types of drainage system 300 Electrical units 347
Ventilation of drains 304 Electrical safety 349
Access to drains 306 Earthing and bonding 351
Connections to existing drains 307 Distribution of supplies in the
Working principles of a good property 354
drainage scheme 308 Current-carrying capacity of
Invert and soffit 309 conductors (cables) 359
Determining drain levels 310 Cables 360
Setting out the incline of a drain 310 Inspecting and testing electrical
Ramps and backdrops 312 installations 365
Testing drains for soundness 312 Ancillary components 367
Tracing drains 316 Regulations relating to electrical
Maintenance of underground appliances in bathrooms 370
drainage systems 316 Further reading 371
Decommissioning 316 Self-testing questions 372
Further reading 316
Self-testing questions 317 Appendix A: Assignments 373
10 Sheet lead roof weatherings 318
Appendix B: NVQ in plumbing —
Introduction 318
Levels 2 and 3 377
Contact with other materials 319
Metal lining of gutters constructed
Appendix C: Central heating control
of timber 320
systems 380
Gutter outlets 322
Covering large flat areas with
lead sheet 322 Appendix D: Whole house boiler-
Wood rolls 324 sizing method for houses 386
Hollow roll work 324
Dormer windows 327 Index 389
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Foreword
It is said that every man is a builder by instinct manner which is simple, direct and easy to
and, while this may be true to a degree, the best understand.
way to become a craftsman is first to be an As most apprentices and trainees nowadays
apprentice. have the advantage of attending a college of
To be an apprentice or trainee means to learn a further education to help them learn their craft,
trade, to learn skills and have knowledge which the publishers of these books have chosen their
will both be a means of earning a living and authors from experienced craftsmen who are also
provide an invaluable expertise for life. But experienced teachers and who understand the
whereas this used to be the main purpose and requirements of craft training and education.
advantage of serving an Aapllpierenticeship, nowadays The learning objectives and self-testing questions
many people in high positions in industry have associated with each chapter will be most useful
made their way to the top after beginning with an to students and also to college lecturers who may
apprenticeship. well wish to integrate the books into their teaching
The once leisurely pace of learning a trade has programme.
now been replaced by a much more concentrated The needs have also to be kept in view of the
period of learning because of the shortened length increasing numbers of late entrants to the crafts
of training. In addition, there is an ever-increasing who are entering a trade as adults, probably under
number of new materials and techniques being a government-sponsored or other similar scheme.
introduced which have to be understood and Such students will find the practical, down-to-earth
assimilated into the craftsman’s daily workload. style of these books to be an enormous help to
There is therefore a large and growing body of them in reaching craftsman status.
knowledge which will always be essential to the L. Jaques
craftsman, and the aim of this craft series of books Formerly Head of Department
is to provide this fundamental knowledge in a Leeds College of Technology
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Preface to the fifth edition
The contents of this volume, as with Book 1 of this from the manufacturers of heating controls. While
series, relate mainly to the technology and practical the use of modern materials and techniques has
activities necessary for the achievement of the simplified many of the traditional methods of
technical and NVQ certificates, levels 2 and 3 in installation, both the design of modern systems and
plumbing. Much of the text will also be helpful to fault diagnosis now form an important part of the
students of associated crafts such as industrial and work of plumbers and heating fitters. It is hoped
domestic heating, gas and oil work and those who that the contents of this volume will help the reader
wish to specialise in underground drainage and lead to achieve both the CGLI Technical Certificate and
sheet weathering at an advanced level. It will also the plumbing NVQ’s level 2/3. In conclusion, it
be helpful to those studying at professional levels in should never be forgotten that a great deal of pride
building subjects. This volume contains much of the and satisfaction can be achieved in knowing that a
necessary information relating to both the Water and job has been done well and carried out in a
Building Regulations, a good knowledge of which is professional manner.
essential for those installing and maintaining hot I would like to record my thanks to Mr D. Davis,
and cold water and heating schemes. the Technical Officer of the Institute of Plumbing
The current area of thought in the light of and Heating, and to the staff of Essex County
diminishing resources and changes in the Library, Chelmsford, for their help in tracing
environment is the government’s commitment to and verifying many of the British and European
energy saving. It is therefore important that Standards listed in this book. Also to Mr M. Mear
plumbers and heating fitters understand the needs for his permission to use illustrations of the Central
for energy conservation, because, due to the nature Heating Calculator, The Institute of Plumbing for
of their work, they can influence to a large degree permission to use the tables and graph relating to
the success or otherwise of energy savings. pipe sizing from the design guide, The Energy
I have endeavoured to implement some of the Saving Trust and TACMA for their permission
suggestions made by readers of the books in this to reprint some of their illustrations and technical
series since the last edition was published and many details. I should also thank all the other companies
of them have been embodied in these new editions that have given me assistance and advice in the
of Books 1 and 2. I have, however, avoided detailed preparation of this book. I must also thank my wife
wiring plans of heating systems as this information Vilma for her help and support in the production of
is freely available in a clear and concise form direct both Books 1 and 2 of this series.
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