Handbook of Valves and Actuators

540 Pages·2007·64.18 MB·English

by  Brian Nesbitt

Handbook of Valves and Actuators:
Valves Manual International
by Brian Nesbitt

• ISBN: 1856174948
• Publisher: Elsevier Science & Technology Books
• Pub. Date: August 2007
Foreword
Valves are one of the most fundamental components ni any process plant. Engineering design relies on a host
of mechanical devices to enable the transportation of product to take place under controlled conditions and
valves are at the heart of .ti
The global control valve market si seeing unprecedented growth as a result of new greenfield plants ni develop-
ing countries and current high investment ni oil and gas exploration and production. A 250,000 bpd refinery
might have as many as 2500 of them installed ni sti pipes and vessels.
Life cycle cost analysis shows the initial purchase price represents around 20% of a valve's total cra-
dle-to-grave cost. Almost three-quarters of the cost si expended on maintenance, major overhauls and repairs,
which offers a huge opportunity for cost reduction.
Process plants have seen a dramatic shift ni their control system architecture, with advanced strategies being
implemented, but critical process flows are still controlled by valves that differ little ni function or appearance
from those ni plants that operated 50 years ago.
Incorrectly specified or underperforming control valves can cost the process plant operator dearly. And that
does not mean simply losses from incorrect maintenance. Factor ni poor product quality, operating disruptions,
safety compliance and other indirect costs, and the figure can grow considerably.
The most effective way to cut control valve costs si to use preventive and predictive maintenance to reduce the
number of valves that require turnaround maintenance. A diagnostic system, capable of evaluating the perfor-
mance of control valves without taking them off line saves plant downtime and provides a far more certain anal-
ysis, because it avoids a possible misdiagnosis that can result from removing the valve from its working envi-
ronment.
The effective management of control valves leads to cost-reduction. Installing correctly specified valves can
improve plant performance and product quality, while extending scheduled maintenance periods. Preventive
maintenance measures, such as regular calibration and physical inspection, can identify areas of concern be-
fore valves require costly repair and disrupt operations.
Predictive maintenance helps an operator see into the device, pinpoint hidden problems and eliminate the
need to isolate good valves. With maintenance consuming the lion's share of a valve's life cycle cost, initial se-
lection and an effectively managed maintenance programme are essential ni a plant operator's drive for cost
reductions.
Valves Manual International si therefore a welcome aid to engineers and users of all disciplines. tI combines, ni
one convenient volume, chapters on fluid theory, terminology, valve and actuator types and selection, materi-
als, QA, testing, installation and maintenance, together with valve applications and solutions and a Buyers'
guide. Users and specifiers will find sensible and practical information to help them make informed decisions
which will impact positively on whole-life costs. This si not simply another textbook on valves an actuators.
lan Leitch
Commercial Director
Energy Industries Council
(London, Houston, Singapore, Rio de Janeiro, Macae, Aberdeen, Dubai and Indonesia)
VALVES MANUAL International III
The editor
Brian Nesbitt si a highly respected consultant specialising ni valve and pump technology. eH works with valve
and pump manufacturers, equipment manufacturers, valve and pump users and others who require specialist
assistance. Brian regularly publishes articles, presents papers, conducts seminars and workshops, and under-
takes work for industry ranging from theoretical research projects and equipment design studies, pump and
valve duty evaluations, to site visits to investigate problem valves, pumps, or problem systems. As a pump and
valve designer, with experience from 01 to 2048 barg he si admirably suitable to discuss lla aspects of valves
and actuators. He si the current chairman of the British Standard MCE/6/6 and European CEN/TC197/SC5
subcommittees which have formulated the draft European Standards for rotary and reciprocating dp pumps
and si the UK Principal Technical Expert to ISO/TC 67/SC6 Joint Working Group 2 for "Oil & Gas" reciprocating
pumps. Brian was one of the UK delegates on the API task-force looking at modifications for the 3rd edition of
API 674 and sti conversion to ISO 13710.
Brian Nesbitt's working career began as a technical apprentice ni the turbo-generator division of CA Parsons,
gaining hands-on experience of building machines up to 500MW. From the shop floor, his promotion led to peri-
ods ni drawing and design offices working on rotary and reciprocating compressors and gas turbines. Large ro-
tary compressors included gas circulators for nuclear reactors. Many machines included specially designed
ancillary systems and complicated lube and seal oil systems. Mechanical seals were designed for specific
compressor applications. Machine installation and interconnection was an important feature on some con-
tracts. Process piping was considered during machine design. A brief spell ni industrial refrigeration, with recip-
rocating and screw compressors and considerable system design and site/installation exposure, was followed
by an introduction to pumps at Ingersoll-Rand where he worked until 1985. Brian was recruited to provide engi-
neering and application support for reciprocating pumps manufactured within Europe. Conversion from recip-
rocating compressors to reciprocating pumps was accomplished by an extended visit to the "parent" factory ni
the USA. During this time, Brian assisted with ongoing design work on current contracts, including critical valve
components on a batch of 2.0 MW pumps.
Once settled ni the ,KU Brian provided guidance to Sales for pump selection and choice of accessories and vis-
ited potential customers to discuss applications. Special pump designs were implemented for duties unsuitable
for standard pumps. Emphasis was directed towards easier maintenance, low NPIPr, high pressure, high vis-
cosity and solids handling applications. New valve designs were produced for arduous applications. North Sea
pump applications and associated quality requirements proved to be a great source of development.
Many pumps required special ancillary systems for the crankcase and the stuffing boxes. On-skid process
pipework featured on a considerable number of pumps where multiple pumps were assembled to create a sin-
gle unit. Close liaison with the test department was essential to ensure test rigs were capable of providing the
required accuracy for a wide range of operating conditions. Brian was very fortunate ni that the test department
had an enviable range of equipment and facilities available, together with very experienced staff. Extensive
tests were conducted, ni parallel with contractual tests, to explore the capabilities of the pump ranges. Novel gir
designs were developed to cope with unusual operating conditions.
Brian also provided support for the after-sales departments with site visits to advise on pump and system oper-
ational problems. Exposure to complicated system problems, such as acoustic resonance, provided opportu-
nities to work with consultants developing leading-edge technologies and investigation methodologies.
While at Ingersoll-Rand, he was surrounded by some of the world's most eminent rotodynamic pump special-
ists and met lots of others who visited the plant regularly. Although not knowing everything about valves and
pumps, Brian does know who will know the answer to those insoluble problems!
VALVES MANUAL International V
Using this book
Written specifically as a practical reference book for valve and actuator users, Valves Manual Intemational is
intended to provide useful information about the outline design, selection and installation of valves and actua-
tors and how these affect performance. Valves Manual International is not intended to be just "another" text-
book on valves; rather it seeks to address the problems that exist at the interface between valve manufacturers
and users. tI has been compiled with the help of and benefit from the practical experience of valve users; it is
aimed at everyone who has technical problems as well as these wanting to know who supplies what, and from
where.
Valves Manual International can be used in a variety of ways depending on the information required. For spe-
cific problems it is probably best used as a reference book. The detailed Contents section at the front of the
book, combined with the Index at the end, will simplify finding the appropriate topic. The "Useful references" at
the end of most Chapters also provide helpful guidance, useful information and suggestions for further reading.
As a textbook though, Valves Manual International may be read from cover to cover to obtain a comprehensive
understanding of the subject. Of course, individual Chapters may be studied separately.
Chapter 1 is an important and probably the most-often referred to Chapter. tI is an A-Z of commonly used terms,
definitions and abbreviations frequently encountered in the daily use of valves and actuators and their associ-
ated systems. Technical terms, unique expressions, concepts, topics, synonyms and acronyms are all defined,
along with an explanation of a number of examples of the misuse of valve, actuator and piping terminology.
With the valve and actuator market being global and with English being used more and more as a universal en-
gineering language, the need for such clarification of important technical terms and definitions is all the more
important. Chapter 1 can be used as a straightforward dictionary ,ro perhaps more effectively, in conjunction
with the reading and study of individual chapters. A number of cross references to the other chapters in the
book are also given and the comprehensive Index at the end of the book is will also be of help in locating topics.
The properties of fluids are discussed in Chapter 2. Chapters 3 to 7 are devoted to the main valve types,
grouped into Isolating, Non-return, Control and Safety relief. Actuators are covered specifically in Chapter .21
The book then follows a logical pattern with Chapters devoted to valve and pipe sizing and then piping and con-
nectors through to sealing arrangements. Ancillary products and services are also discussed. Testing and
quality assurance is dealt with in Chapter 15. Chapters 16 and 17 are devoted to valve and actuator standards.
Chapter 19 is concerned with installation, commissioning and maintenance as well as efficiency, economics
and selection.
Chapter 18 provides details of a number of interesting valve and actuator applications and solutions that illus-
trate some of the problems encountered in the practical use of valves and how these have been solved. This
Chapter embraces a number of valve and actuator designs and uses, showing some of the diverse uses for
these products outside the more traditional areas. Chapter 20 gives useful guidance and information on many
fluid properties and brings together data on liquids, gases as well as important units and conversions used in
valve selection and in making preliminary design decisions.
The Buyers' Guide, Chapter 21, summarises the various valve types, divided them into Isolating, Non-return,
Control, Safety relief and Actuators, based on the individual Chapters in the book devoted to each type. The
Guide has been grouped in this way to simplify representation of the major generic valve groups. This is due to
the difficulty in trying to impose tight boundaries on various valve and actuator type descriptions used in various
parts of the world.
This is followed by Ancillary products and services. Trade/brand names are comprehensively listed too. tI is
preceded by the names and addresses and contact details of all companies appearing in the Guide. They are
listed alphabetically, by country.
Although each Chapter describes in detail all the valve types that have been placed within that generic group, it
is strongly recommended that direct contact with the relevant companies is made - initially perhaps via their
websites - to ensure that their product ranges are clearly identified from the broad classification and that these
details can be clarified wherever necessary.
VALVES MANUAL International VII
Table of Contents

Foreword, Page III, Ian Leitch

The editor, Page V

Using this book, Page VII

1 - Definitions and abbreviations, Pages 1-41

2 - Properties of fluids, Pages 43-79

3 - Isolating valves, Pages 81-130

4 - Non-return valves, Pages 131-141

5 - Regulators, Pages 143-150

6 - Control valves, Pages 151-173

7 - Safety relief valves, Pages 175-191
8 - Valve and piping sizing, Pages 193-213

9 - Piping and connectors, Pages 215-252

10 - Noise in valves, Pages 253-261

11 - Valve stem sealing, Pages 263-277

12 - Actuators, Pages 279-310

13 - Valve materials, Pages 311-336

14 - Instrumentation and ancillaries, Pages 337-341

15 - Quality, inspection and testing, Pages 343-351

16 - Standards and specifications, Pages 353-379

17 - Installation and maintenance, Pages 381-395
18 - Some applications and solutions, Pages 397-423

19 - Valve and acutuator selection, Pages 425-432

20 - Fluid properties & conversions, Pages 433-483

21 - Buyers' guide, Pages 485-531

Index, Pages 532-545

Index to advertisers, Page 546

Acknowledgements, Page 546
1
Definitions and abbreviations
This Chapter si an A-Z of commonly used terms, definitions and abbreviations frequently encountered ni
the daily use of valves and actuators and their associated systems.
Technical terms, unique expressions, concepts, topics, synonyms and acronyms are lla defined, along
with an explanation of a number of examples of the misuse of valve, actuator and piping terminology.
With the valve and actuator market being increasingly global and with English being used more and
more as a universal engineering language, the need for such clarification of important technical terms,
abbreviations and definitions si lla the more important.
The Chapter can be used as a straightforward dictionary ,ro perhaps more effectively, ni conjunction
with the reading and study of individual chapters. A number of cross references to other chapters ni the
book are also given and the comprehensive Index at the end of the book si will also be of help ni
locating topics.
VALVES MANUAL International 1
1 Definitions and abbreviations
Definitions and abbreviations pipework. Sound waves travel successfully around corners
hence pipe bends do not divide piping systems into a collection
A of straight lengths.
Actuator
3-A
The device fitted to a valve for moving the sealing element. The
3-A Sanitary Standards, Inc. (of USA). An American company
actuator can be a handwheel for manual operation or a dia-
which writes voluntary "accepted practices" to maintain good
phragm or piston powered by compressed air or hydraulics.
hygiene within food handling processes.
Actuator stiffness
AA
The force per unit length, N/mm, required to move the actuator
Aluminium Association (of America)
stern without the positioner driving the actuator. When a pneu-
Absolute pressure
matic diaphragm actuator is set ni a specific position the dia-
The actual pressure, not a pressure compared to the local at- phragm casing contains a fixed volume of air. The air volume is
mospheric pressure. Gauge pressure refers the measured elastic because air is compressible. If a force is applied to the
pressure to the local atmosphere, nominally 101.325 kPa (ab- actuator stem it will deflect as the air compresses or expands.
solute). The stiffness of fluid powered actuators is dependent upon the
fluid volume and therefore the stroke position. Electromechani-
ABNT
cal actuators have fairly constant stiffness. Actuator stiffness
Associa(;~o Brasileira de Normas T~cnicas, the National Stan- for various types si listed ni Table 1.2.
dards Authority of Brazil.
Absolute pressure regulator Most stiff lacinahcem-ortcelE
ciluardyh-ortcelE
A regulator which maintains a sub-atmospheric pressure rather
Double-acting pneumatic piston
than a positive gauge pressure.
Single-acting pneumatic piston
Accuracy Most flexible Pneumatic diaphragm
The variation ni the controlled variable between the minimum Table 1.2 Actuator stiffness
controllable flow and the rated flow. The value si equal to 100%
AECMA-STAN see ASD-STAN
minus the offset, see Figure 1.2.
AENOR
Accumulation
The pressure increase above the system design pressure or Asociaci6n EspaSola de Normalizaci6n y Certificaci6n, the Na-
system maximum allowable working pressure (MAWP) during tional Standards Authority of Spain.
safety valve operation. If the accumulation is limited to 10% and AFNOR
the overpressure is 25% then the set pressure must be 110/125
Association fran;aise de normalisation, the National Standards
= 0.88 = 88% of system design pressure, maximum.
Authority of France
ACI
Air loaded regulator
Alloy Casting Institute, a division of the Steel Founders' Society
of America, has a series of identification codes for alloy and Another name for an External pressure loaded regulator.
stainless steels, see Table 1.1. AlSl
American Iron and Steel Institute
AISI ACl Cr/NilMo
AI
303 F61-FC 6.0/9/81
403 8-FC 9/91 Aluminium is used as a light, corrosion resistant metal and also
as an alloying element ni steels. Aluminium is the strongest
304L 3-FC 01/91
deoxidiser and also combines with nitrogen, present ni air, to re-
013 02-KC 02/52 duce strain ageing. tI si also useful ni inhibiting grain growth and
613 M8-FC 2/21/71 improves scale resistance for hot applications.
L613 M3-FC 2/21/71 AIIotropy
713 21-GC 3/31/91
The property possessed by certain elements to exist ni two or
743 C8-FC 11/81 more distinct forms that are chemically identical but have differ-
51-AC 1/21 ent physical properties. nI the case of iron the crystal structure
410 M51-AC 1/1/21 has one form at room temperature and another at high temper-
MN6-AC 1/4/21 ature. When heated above 910~ the atomic structure changes
from body-centred cubic to face -centred cubic but reverts
HP4-71 uC7-BC 4/71
again when cooled. The allotropy of iron modifies the solubility
420 04-AC 1/21
of carbon, and it si because of this that steel can be hardened.
Table 1.1 ACI identification codes Altitude valve
Acme thread An accurate pressure reducing regulator combined with a re-
A thread form similar to square threads but the thread flanks verse differential pressure regulator used to maintain the level
form an included angle of 29 ~ The Acme thread is stronger ni a liquid reservoir. When system pressure is high liquid is sup-
than a square thread and is easier to machine. Thread si rolled plied to the reservoir until the maximum level is reached. If the
rather than cut to improve strength and surface finish. Used on system pressure falls below the reservoir pressure liquid is re-
the stems of some linear valves. leased into the system. Used extensively ni water distribution
systems with local water towers.
Acoustic resonance
Amplifier valve
Severe pressure pulsations caused when an exciting fre-
quency coincides with an organ pipe natural frequency of the Another name for the pilot valve ni a Pilot-operated regulator.
2 VALVES MANUAL International
1 Definitions and abbreviations
AMS ANSI
The American National Standards Institute, the National Stan-
Aerospace Materials Specifications (from SAE specifications)
dards Authority of the USA.
Anaerobic
API
Usually applied to liquid gaskets, thread seals and impregna-
The American Petroleum Institute
tion compounds to indicate the hardening or thickening process
API pipe thread see NPT
commences after assembly or application when air is excluded.
Arc welding
Analogue signal
An electric welding process where the necessary heat is pro-
A signal which varies ni intensity. Typical analogue signals are vided by striking an electric arc between two conductors. One of
pneumatic; 0.2 to 0.1 barg; electric; 0 to 10V or 4 to 20 mA.
the conductors is the workpiece, the other can be a non-con-
Angle valve sumable electrode or a consumable weld filler material.
ARSO
Avalve body style which has the process connections at 90~
African Regional Standards Organisation
Annealing
ASD-STAN
Heating steel to, and holding at a suitable temperature, fol-
Aerospace and defence industries association of Europe -
lowed by relatively slow cooling. The purpose of annealing may
Standardisation
be to remove stresses, to soften the steel, to improve
machinability, to improve cold working properties, to obtain a Asbestos fibre
desired structure. The annealing process usually involves al- A natural mineral fibre which has good mechanical properties
lowing the steel to cool slowly ni the furnace. and chemical resistance at high temperatures. No longer a
Anti-static design popular material due to the possible health risk but can be used
for difficult applications as a last resort.
A design which provides electrical continuity for the moving
ASME
valve components and across the valve body to the connected
piping. American Society of Mechanical Engineers
Aspirator
AOD
Another name for a Pitot tube.
Argon-oxygen decarburisation, a( stainless steel refining pro-
cess) ASRO
Approved materials Asociatia de Standardizare din Romania, the National Stan-
dards Authority of Romania.
When valves are to be used with fluids for human consumption,
ASTM
e.g.. water, milk, food products; or valves are to be used ni man-
ufacturing processes where contamination would degrade or American Society for Testing and Materials
destroy a critical fluid constituent, only tested and approved Atmospheric pressure
materials of construction are allowed. Several bodies have lists
Atmospheric pressure is standardised, technically, at 101.325
of approved materials or will make a judgement on a specific
kPa(absolute), equivalent to 14.696 psi(a). Remember! This is
material. Table 3.1 is indicative:
the pressure at sea level. Equipment working at altitude will not
experience the same atmospheric pressure. Also the local at-
yrtnuoC slavorppA ydoB
mospheric pressure changes with the weather. Local values
Belgium ASEAU are likely to vary from 94 to 108 kPa at sea level.
Denmark VA Austempering
France AFNOR Association Fran~iase de
Quenching from a temperature above the transformation range
Normalisation Beaureau Veritas
to a temperature above the upper limit of martensite formation,
Germany DVGW Deutscher Verein vor Gas-und and holding at this temperature until the austenite is completely
IB Wasserfachmannern Bau Institut
transformed to the desired intermediate structure, for the pur-
Italy INU Ente Nazionale Italiano de Unificazione pose of conferring certain mechanical properties.
The Netherlands KIWA Keurings Instituut voor Austenite
Waterleiding-Artikelen
A face centred cubic crystal structure found ni chrome-nickel
Norway GNFS
stainless steels.
Sweden PV
Austenitic stainless steel
Switzerland SVGW
Steels containing high percentages of certain alloying elements
UK IWD The Drinking Water Inspectorate
such as manganese and nickel which are austenitic at room
WFB
temperature and cannot be hardened by normal heat-treat-
WRc The Water Research Council
ment but do work harden. They are also non-magnetic ni the
USA FDA Food and Drink Administration
annealed condition and very corrosion resistant. Chromium
USDA The US Department of Agriculture
content usually falls between 61 and 26% and nickel content
less than 35%. Typical examples of austenitic steels include the
Table 1.3 Learned bodies approving materials of construction
18/8 stainless steels and 41 % manganese steel. Work harden-
For the specific area of drinking water there is no European
ing or welding may induce some magnetism.
Standard. This is because the member countries have adopted
Autoclavable
different approaches to the problem and rationalisation is not
possible without enormous expenditure ni some countries. The ability of a valve to be heated ni an oven for sterilisation.
CEN is considering the problem at present. National Standards The time and temperature being dependent upon the organism
prevail ni this area. to be destroyed. Lower temperatures are usually applied for
VALVES MANUAL International3