Valve selection handbook 4th

To
Henry
Hanke
in
memory
Valve Selection Handbook
Fourth
Edition
Copyright
©
1981,
1987,
1991,1999
by
Elsevier Science.
All rights
reserved.
Printed
in the
United States
of
America. This book,
or
parts thereof,
may not be
reproduced
in any
form
without permission
of the
publisher.
Originally published
by
Gulf Publishing Company,
Houston,
TX.
For
information,
please
contact:
Manager
of
Special Sales
Elsevier Science
200
Wheeler Road
Burlington,
MA
01803-2041
Tel:
781-313-4700
Fax:781-313-4882
For
information
on all
Gulf Professional Publishing titles available, contact
our
World Wide
Web
home page
at:
http://www.bh.com/gulf
10
98765432
Library
of
Congress
Cataloging-in-Publication
Data
Zappe,
R. W.,
1912-
Valve
selection handbook
/ R. W.
Zappe,
—4
th
ed.
p. cm.
Includes bibliographical references
and
index.
ISBN
0-88415-886-1
1.
Valves—Handbooks,
manuals,
etc.
I.
Title.
TS277.Z37
1998
621.8'4—dc21
98-36482
CIP
Printed
on
Acid-Free Paper
(oo)
The
information,
opinions
and
recommendations
in
this book
are
based
on the
author's
experience
and
review
of the
most current knowledge
and
technology,
and are
offered
solely
as
guidance
on the
selection
of
valves
for the
process industries.
While
every care
has
been taken
in
compiling
and
publishing this work, neither
the
author
nor the
publisher
can
accept
any
liability
for the
actions
of
those
who
apply
the
information herein.
CONTENTS
Preface,
xii
1
Introduction
1
Fundamentals,
1.
Manual Valves,
2.
Check Valves,
2.
Pressure
Relief Valves,
2.
Rupture Discs,
3.
Units
of
Measurements,
3.
Identification
of
Valve Size
and
Pressure Class,
4.
Standards,
4.
2
Fundamentals
5
Fluid
Tightness
of
Valves,
5
Valve
Seals,
5.
Leakage Criterion,
5.
Proving Fluid
Tightness,
6.
Sealing
Mechanism,
8
Sealability Against Liquids,
8.
Scalability
Against Gases,
9.
Mechanism
for
Closing Leakage Passages,
10.
Valve
Seatings,
11
Metal Seatings,
11.
Sealing with Sealants,
13.
Soft
Seatings,
13.
v
Gaskets,
14
Flat Metallic Gaskets,
14.
Compressed Asbestos Fiber
Gaskets,
15.
Gaskets
of
Exfoliated Graphite,
16.
Spiral Wound Gaskets,
17.
Gasket Blowout,
19.
Valve
Stem
Seals,
20
Compression Packings,
20.
Lip-Type Packings,
24.
Squeeze-Type Packings,
25.
Thrust Packings,
26.
Diaphragm Valve Stem Seals,
26
Flow Through Valves,
27
Resistance Coefficient
£,
27.
Flow Coefficient
C
v
,
32.
Flow Coefficient
K
v
,
33.
Flow
Coefficient
A
v
,
34.
Interrelationships Between Resistance
and Row
Coefficients,
35.
Relationship
Between Resistance
Coefficient
and
Valve
Opening Position,
35.
Cavitation
of
Valves,
37.
Waterhammer
from
Valve Operation,
39.
Attenuation
of
Valve Noise,
43.
3
Manual Valves
45
Functions
of
Manual
Valves,
45
Grouping
of
Valves
by
Method
of
Flow Regulation,
45
Selection
of
Valves,
47
Valves
for
Stopping
and
Starting Flow,
47.
Valves
for
Control
of
Flow Rate,
47.
Valves
for
Diverting Flow,
47.
Valves
for
Fluids with
Solids
in
Suspension,
47.
Valve
End
Connections,
48.
Standards Pertaining
to
Valve Ends,
49.
Valve Ratings,
49.
Valve
Selection Chart,
50.
Globe Valves,
51
Valve
Body Patterns,
52.
Valve Seatings,
57.
Connection
of
Disc
to
Stem,
60.
Inside
and
Outside Stem Screw,
60.
Bonnet
Joints,
61.
Stuffing
Boxes
and
Back Seating,
62.
Direction
of
Flow Through Globe Valves,
64.
Standards Pertaining
to
Globe Valves,
64.
Applications,
65.
Piston Valves,
65
Construction,
65.
Standards Pertaining
to
Piston Valves,
69.
Applications,
69.
VI
Parallel Gate
Valves,
69
Conventional Parallel Gate Valves,
70.
Conduit Gate Valves,
74.
Valve Bypass,
77.
Pressure-Equalizing Connection,
77.
Standards Pertaining
to
Parallel Gate Valves,
79.
Applications,
79.
Wedge Gate Valves,
79
Variations
of
Wedge Design,
82.
Connection
of
Wedge
to
Stem,
86.
Wedge Guide Design,
86.
Valve Bypass,
87.
Pressure-Equalizing Connection,
87.
Case Study
of
Wedge
Gate Valve Failure,
88.
Standards Pertaining
to
Wedge Gate
Valves,
88.
Applications,
90.
Plug Valves,
90
Cylindrical Plug Valves,
92.
Taper Plug Valves,
95.
Antistatic
Device,
98.
Plug Valves
for
Fire Exposure,
98.
Multiport
Configuration,
98.
Face-to-Face
Dimensions
and
Valve
Patterns,
99.
Standards Pertaining
to
Plug Valves, 100.
Applications, 100.
Ball Valves,
101
Seat Materials
for
Ball Valves, 101. Seating Designs, 102.
Pressure-Equalizing Connection, 106. Antistatic Device, 108.
Ball Valves
for
Fire
Exposure, 109. Multiport Configuration,
109. Ball Valves
for
Cryogenic Service,
110.
Variations
of
Body
Construction,
110.
Face-to-Face
Dimensions,
110.
Standards Pertaining
to
Ball Valves,
112.
Applications,
112.
Butterfly
Valves,
112
Seating Designs,
114.
Butterfly
Valves
for
Fire Exposure, 126.
Body
Configurations, 126. Torque Characteristic
of
Butterfly
Valves,
126. Standards Pertaining
to
Butterfly
Valves, 129.
Applications, 129.
Pinch Valves,
130
Open
and
Enclosed Pinch Valves, 130. Flow Control with
Mechanically Pinched Valves, 132. Flow Control with Fluid-
Pressure Operated Pinch Valves, 132. Valve Body, 133.
Limitations, 134. Standards Pertaining
to
Pinch Valves,
134.
Applications,
135.
VII
Diaphragm
Valves,
135
Weir-Type
Diaphragm Valves, 136. Straight-Through
Diaphragm Valves, 137. Construction Materials, 138.
Valve
Pressure/Temperature
Relationships, 139. Valve Flow
Characteristics,
139. Operational Limitations, 139. Standards
Pertaining
to
Diaphragm Valves, 140.
Applications,
140.
Stainless
Steel Valves,
141
Corrosion-Resistant Alloys, 141. Crevice Corrosion, 141.
Galling
of
Valve Parts,
141.
Light-Weight
Valve
Constructions, 142. Standards Pertaining
to
Stainless
Steel
Valves, 142.
4
Check
Valves
143
Function
of
Check Valves,
143
Grouping
of
Check Valves, 143. Operation
of
Check Valves,
149. Assessment
of
Check Valves
for
Fast
Closing,
151.
Application
of
Mathematics
to the
Operation
of
Check
Valves,
151.
Design
of
Check Valves,
152
Lift
Check Valves, 152. Swing Check Valves, 153. Tilting-
Disc Check Valves, 154. Diaphragm Check Valves, 155.
Dashpots, 156.
Selection
of
Check Valves,
157
Check
Valves
for
Incompressible Fluids, 157. Check Valves
for
Compressible Fluids, 157. Standards Pertaining
to
Check
Valves,
157.
5
Pressure
Relief
Valves
158
Principal Types
of
Pressure
Relief Valves,
158
Terminology,
160
Pressure Relief Valves, 160. Dimensional Characteristics, 162.
System Characteristics, 162. Device Characteristics, 163.
VIII
Direct-Loaded
Pressure
Relief Valves,
165
Review, 165. Safety Valves, 168.
Safety
Relief Valves, 171.
Liquid
Relief Valves, 177. Vacuum Relief Valves, 180.
Direct-Loaded Pressure Relief Valves with Auxiliary
Actuator,
182. Oscillation Dampers, 188. Certification
of
Valve
Performance, 190.
Force/Lift
Diagrams
as an Aid for
Predicting
the
Operational Behavior
of
Spring-Loaded
Pressure Relief Valves,
191.
Secondary Back Pressure
from
Flow-Through Valve Body, 198. Verification
of
Operating
Data
of
Spring-Loaded Pressure Relief Valves Prior
to and
after
Installation,
200
Pilot-Operated
Pressure
Relief Valves,
202
Pilot-Operated Pressure Relief Valves with
Direct-Acting
Pilot, 202. Stable Operation
of
Valves with
On/Off
Pilots, 209.
Pilot-Operated
Pressure Relief Valves with
Indirect-Acting
Pilot,
211.
Rupture
Discs
214
Terminology,
215. Application
of
Rupture Discs, 216.
Limitations
of
Rupture Discs
in
Liquid Systems, 218.
Construction
Materials
of
Rupture Discs, 218. Temperature
and
Burst Pressure Relationships, 220. Heat Shields,
221.
Rupture
Disc Application Parameters,
221.
Metal Rupture
Discs,
223
Tension-Loaded Types, 223. Compression-Loaded Types, 230.
Graphite Rupture
Discs,
239. Rupture Disc
Holders,
242.
Clean-Sweep Assembly, 244. Quick-Change Housings, 244.
Accessories, 246. Double Disc Assemblies, 246. Selecting
Rupture
Discs, 248. Rupture Disc Device
in
Combination
with
Pressure Relief Valve, 249. Explosion
Vent
Panels, 252.
Reordering Rupture Discs, 254.
User's
Responsibility, 255.
IX
7
Sizing Pressure Relief Devices
256
Sizing
of
Pressure
Relief Valves
Gas,
Vapor,
Steam,
260
Sizing Equations
for Gas and
Vapor other than Steam,
261.
Sizing Equations
for Dry
Saturated Steam,
264.
Sizing
Equations
for
Liquids
Flow,
267
Influence
of
Inlet Pressure Loss
on
Valve Discharge
Capacity,
269
Sizing
of
Inlet
Piping
to
Pressure
Relief Valves,
271
Sizing
of
Discharge Piping
of
Pressure
Relief Valves,
272
Sizing
of
Rupture Discs,
274.
Rupture Disc Sizing
for
Nonviolent
Pressure Excursions,
274.
Sizing Equations
for
Gas or
Vapor,
275.
Rupture Disc Sizing
for
Violent Pressure
Excursions
in
Low-Strength Containers,
277.
APPENDIX
A
ASME Code Safety Valve Rules
279
APPENDIX
B
Properties
of
Fluids
283
APPENDIX
C
Standards Pertaining
to
Valves
290
APPENDIX
D
International System
of
Units (S.I.)
299
References
317
Index
321
x
PREFACE
Valves
are the
controlling
elements
in
fluid
flow and
pressure
systems.
Like many other engineering components, they have developed over
some three centuries
from
primitive arrangements into
a
wide range
of
engineered units
satisfying
a
great variety
of
industrial needs.
The
wide range
of
valve types available
is
gratifying
to the
user
because
the
probability
is
high that
a
valve exists that matches
the
appli-
cation.
But
because
of the
apparently innumerable alternatives,
the
user
must
have
the
knowledge
and
skill
to
analyze each application
and
deter-
mine
the
factors
on
which
the
valve
can be
selected.
He or she
must also
have
sufficient
knowledge
of
valve types
and
their construction
to
make
the
best selection
from
those available.
Reference manuals
on
valves
are
readily
available.
But few
books,
if
any,
discuss
the
engineering
fundamentals
or
provide in-depth informa-
tion
about
the
factors
on
which
the
selection should
be
made.
This book
is the
result
of a
lifelong
study
of
design
and
application
of
valves,
and it
guides
the
user
on the
selection
of
valves
by
analyzing
valve
use and
construction.
The
book
is
meant
to be a
reference
for
prac-
ticing
engineers
and
students,
but it may
also
be of
interest
to
manufac-
turers
of
valves, statutory authorities,
and
others.
The
book discusses
manual
valves, check valves, pressure relief valves
and
rupture discs.
Revisions
in the
fourth
edition include
a
full
rewriting
of the
chapters
on
pressure relief valves
and
rupture discs.
These
revisions take
full
account
of
current U.S.
practice
and the
emerging
European standards.
I
wish
to
express
my
thanks
to the
numerous individuals
and
compa-
nies
who
over
the
years
freely
offered
their advice
and
gave permission
XI
to
use
their material
in
this book. Because
the
list
of the
contributors
is
long,
I
trust
I
will
be
forgiven
to
mention only
a few
names:
My
thanks
go to the
late Frank Hazel
of
Worcester Controls
for his
con-
tribution
to the
field
of
manual valves;
in the
field
of
pressure relief valves
to
Jurgen
Stolte
and the
late
Alfred Kreuz
of
Sempell
A.G.;
Manfred
Holfelder
of
Bopp
&
Reuther G.m.b.H.;
and Mr.
Gary
B.
Emerson
of
Anderson, Greenwood
& Co. In the
field
of
rupture discs,
my
thanks
to
Tom
A.
LaPointe, formerly
of
Continental Disc Corporation,
and G. W.
Brodie, formerly
a
consultant
to
Marston Palmer Limited.
R. W.
Zappe
XII
1
INTRODUCTION
Valves
are the
components
in a fluid flow or
pressure system that regu-
late either
the flow or the
pressure
of the fluid.
This
duty
may
involve
stopping
and
starting
flow,
controlling
flow
rate, diverting
flow,
prevent-
ing
back
flow,
controlling pressure,
or
relieving pressure.
These
duties
are
performed
by
adjusting
the
position
of the
closure
member
in the
valve. This
may be
done either manually
or
automatically.
Manual
operation also includes
the
operation
of the
valve
by
means
of a
manually
controlled power operator.
The
valves discussed here
are
man-
ually
operated valves
for
stopping
and
starting
flow,
controlling
flow
rate,
and
diverting
flow; and
automatically operated valves
for
prevent-
ing
back
flow and
relieving pressure.
The
manually operated valves
are
referred
to as
manual valves, while valves
for the
prevention
of
back
flow
and
the
relief
of
pressure
are
referred
to as
check valves
and
pres-
sure relief valves, respectively.
Rupture
discs
are
non-reclosing
pressure-relieving devices which ful-
fill
a
duty
similar
to
pressure relief valves.
Fundamentals
Sealing performance
and flow
characteristics
are
important aspects
in
valve selection.
An
understanding
of
these aspects
is
helpful
and
often
essential
in the
selection
of the
correct
valve. Chapter
2
deals
with
the
fundamentals
of
valve seals
and flow
through valves.
1

Xem chi tiết: Valve selection handbook 4th