All pages

Index
Valve Types and Features ... ... 01

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Recommended Flow Characteristics ... ... 07
General Useage Information ... ... 11
Chemical Resistance Chart ... ... 17

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Definition of Valve Sizing ... ... 29
Valve Sizing Procedure ... ... 32
Graphical Statement of Valve Coefficient [Cv] ... ... 36 Managing Director

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Velocity Limitation & Its Calculation
Noise Prediction Methods and Counter measures ...
... ...
...
42
43
Introductory Notes

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Conversion Charts ... ... 43 We have tried our level best to collect maximum Engineering
Virtual Pressure Conversion Chart ... ... 46 information required for the valve study selection along with
Physical Properties of Plastics ... ... 47 a list of approximately 500 fluids against which the resilient,
Physical Properties of Liquids ... ... 48 plastic and metallic materials used in our valves are rated.

Physical Properties of Gases ... ... 50 These ratings, in many cases do not necessarily agree with
those found in other publications.
Physical Properties of Water ... ... 52
Density of Fluids ... ... 53
In the case or resilient materials, the ratings are mostly
General Properties of Elastomer ... ... 54 based on percentage swell of the material but due
Critical Pressures and Temperatures ... ... 55 consideration is given to actual experience or test due to
Saturated Steam Table ... ... 56 temperature, abrasion resistance, permeability, loss of
Schedule 80 Thermoplastic Pipe Standards ... ... 57 resiliency or elasticity, etc of the specific compounds being
Area Conversions ... ... 57 used.
Velocity Conversions ... ... 57
This data is helpful in selecting resilient materials of valves
Force Conversions ... ... 58
to handle a particular fluid. However the combination of
Density Conversions ... ... 58
metallic or plastic materials used in a valve must be known.
General Heat Conversons ... ... 58
The valve parts in contact with the media can be determined
Force & Velocity ... ... 59
by referring to the specific bulletin write up in the catalogue.
Temperature Conversions ... ... 59
The data does not list available valves to handle each fluid
Capacity and Flow Rate ... ... 60 since we have so many different kinds. For special critical
Length Conversions ... ... 60 application refer Sude.
Volume Conversions ... ... 60
Volumetric Rate of Flow Conversions ... ... 61 Frequently the varied complicated and entirely predictable

Class 125 Cast Iron and Class 150 Steel Raised Face Flanges 61 mechanics of corrosion produce unexpected results. No list
of this type can be considered full proof for every field
Class 250 Cast Iron and Class 300 Steel Raised Face Flanges 62
condition.
Class 400 Steel Raised Face Flanges ... ... 62
Class 600 Steel Raised Face Flanges ... ... 63
Use it as a guide only we once again request to consult us
Pipe Flanges - Tables "D" and "E” ... ... 63 for valve selection for details refer General usages
Pipe Flanges - Tables "F" and "H” ... ... 64 information.
Head Office, Bangalore

Valve Types and Features
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The main valve types have many variations and may have different names depending upon manufacturer. Careful

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selection and detailed specifications are required to insure that design and performance requirements are met.

The three basic functions of valves are: 1. to stop flow, 2. to keep a constant direction of flow, and 3. to regulate the flow

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rate and pressure. To select the correct valve to fulfill these functions properly, an outline of the different types of valves
and their features is given below.

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a) Gate Valve

Open
S
Closed
Figure-1 Gate valve flow configuration

lits name implies, the gate is lowered to cut off the path of flow.
Like

For use as an on/off valve (not suitable as a control valve).
l

l resistance to flow when fully open (allows smooth flow)
Little

l stroke requires time to open and close; not suitable for quick operation
Long

The gate valve is one of the most common valves used in liquid piping. This valve, as a rule, is an isolation valve used to
turn on and shut off the flow, isolating either a piece of equipment or a pipeline, as opposed to actually regulating flow.
The gate valve has a gate-like disc which operates at a right angle to the flow path. As such, it has a straight through port
that results in minimum Turbulence erosion and resistance to flow. However because the gate or the seating is
perpendicular to the flow, gate valves are impractical for throttling service and are not used for frequent operation
applications.

Repeated closure of a gate valve, or rather movement toward closure of a gate valve, results in high velocity flow. This
creates the threat of wire drawing and erosion of seating services. Many gate valves have wedge discs with matching
tapered seats. Therefore, the re-facing or repairing of the seating surfaces is not a simple operation. Gate valves should
not, therefore, be used frequently to avoid increased maintenance costs. In addition, a slightly open gate valve can cause
turbulent flow with vibrating and chattering of the disc.

A gate valve usually requires multiple turns of its operator in order to be opened fully. The volume of flow through the
valve is not in direct proportion the number of turns.

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b) Ball Valve

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Ball valves with standard materials are low cost, compact, lightweight, easy to install, and easy to operate refer Figure 2.
They offer full flow with minimum turbulence and can balance or throttle fluids. Typically, ball valves move from closed to
full open in a quarter of a turn of the shaft and are, therefore, referred to as quarter turn ball valves. Low torque

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requirements can permit ball valves to be used in quick manual or automatic operation, and these valves have a long
reliable service life. Ball valves can be full ball or other configurations such as V-port.

Ball valves employ a complete sphere as the flow controlling member, refer Figure-2 . They are of rotary shaft design and

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include a flow passage. There are many varieties of the full ball valves, and they can be trunion mounted with a single
piece ball and shaft to reduce torque requirements and lost motion.

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One of the most popular flow controlling members of the throttling-type ball valves is a V-port ball valve. A V-port ball
valve utilizes a partial sphere that has a V- shaped notch in it. This notch permits a wide range of service and produces an
equal percentage flow characteristic. The straight-forward flow design produces very little pressure drop, and the valve is
suited to the control of erosive and viscous fluids or other services that have entrained solids or fibers. The V-port ball
remains in contact with the seal, which produces a shearing effect as the ball closes, thus minimizing clogging.

Open

Closed

Figure-2 Ball valve flow configuration

l stopper is ball-shaped.
Valve
For use as an on/off valve (not suitable as a control valve).
l
l resistance to flow when fully open (allows smooth flow).
Little
Optimal for automated operation with a 90 degrees operating angle.
l
Advanced technology is required to manufacture ball.
l

c) Butterfly Valve

Open

Closed

Figure-3 Butterfly valve flow configuration

02 Engineering Manual SDTORK SUDE

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l shaped like a butterfly.
Valve
l shut-off and can be used as a control valve.
Tight

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l resistance to flow (allows smooth flow).
Little
Optimal for automated operation with a low operating torque and 90 degrees operating angle.
l
Lightweight and compact.
l

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Butterfly valves(refer figure-3) provide a high capacity with low pressure loss and are durable, efficient, and reliable. The

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chief advantage of the butterfly valve is its seating surface. The reason for this advantage is that the disc impinges
against a resilient liner and provides bubble tightness with very low operating torque. Butterfly valves exhibit an
approximately equal percentage of flow characteristic and can be used for throttling service or for on/off control.

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Typical butterfly bodies include a wafer design, a lug wafer design (a wafer with the addition of lugs around the bodies), and a
flanged design. In all designs, butterfly valves are typically made with standard raised face piping flanges. Butterfly valves are
available standard in sizes up to 72 inches for many different applications. The operators can be either pneumatic or electric.

Comparison of Cv value Comparison of pressure loss Inherent flow characteristics
(Butterfly valve =1) (Butterfly valve=1) P=Constant
100
5

en
op
80
ck
ui
Q
2
60
Cv%

e ar
Lin
1.5
40 %
1 1 ual
0.7 20 Eq

0.2 0.2 0
Butterfly Globe Ball Gate Butterfly Globe Ball Gate 0 20 40 60 80 100
valve valve valve valve valve valve valve valve
Valve opening %

Figure-4 Comparison statement of Butterfly valves with other valves on characteristics and valve Cv.

In Butterfly valves the normal flow means turbulent flow: In this stage, valve flow rate increases in proportion to the square root
of the differential pressure.
Cavitations flow has three stages corresponding to the increase in differential pressure.

A) Incipient cavitations stage
B) Critical cavitations stage
C) Full cavitations stage

Noise and oscillation may cause damage to the valve and downstream-side piping. This occurs when pressure on the valve
downstream side drops below the vapour pressure of the liquid. The fluid changes from liquid to gas, bringing rapid velocity
change and volume expansion. These two factors are the main causes of a flashing noise. Flashing noise is of lower level than
cavitations noise because gas acts as a cushion.

Attention must be paid to materials of the valve body (e.g., upgrading to stainless steel or Chromium molybdenum steel) or the
type of downstream-side piping.

The Butterfly valves produces higher Cv as compare to other types valves, refer Figure-4.


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Cavitations reduction treatment

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The following are the main methods for reducing or preventing capitation damage to valves.
Install valves in series and control them. This method is for reducing the pressure load on each valve. In this case, space
valves out at least 4D (4 times the pipe diameter).

d) Plug Valves

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Plug valves are another type of isolation valve designed for uses similar to those of
gate valves, where quick shutoff is required. They are not generally designed for flow
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regulation. Plug valves are sometimes also called cock valves. They are typically a
quarter turn open and close. Plug valves have the capability of having multiple outlet
ports. This is advantageous in that it can simplify piping. Plug valves are available
with inlet and outlet ports with four-way multi-port valves which can be used in place of
two, three or four straight valves.

e) Globe Valve / Angle valves

Open

Closed
Figure-5 Globe valve/Angle valve flow configuration

The globe-shaped body controls the fluid into a S-shaped flow.
l

l shut-off and can be used as a control valve.
Tight
l resistance to flow (does not allow smooth flow).
Large
l power is required to open and close the valve (not suitable for large sizes).
Much

Liquid flow does not pass straight through globe valves. Therefore it causes an increased resistance to flow and a
considerable pressure drop. Angle valves are similar to globe valves; however, the inlet and outlet ports are at 900 angles
to one another, rather than at 1800 angles. Because of this difference, the angle valves have slightly less resistance to flow
than globe valves.

There are a number of common globe valve seating types.

The seating of the plug in a globe valve is parallel to the line liquid flow. Because of this seating arrangement, globe valves are
very suitable for throttling flow with a minimal seat erosion or threat of wire drawing.

A globe valve opens in direct proportion to the number of turns of its actuator. This feature allows globe valves to closely
regulate flow, even with manual operators. For example, if it takes four turns to open a globe valve fully, then approximately
one turn of a hand wheel will release about 25% of the flow, two turns will release 50%, and three turns will release 75%. In
addition, the shorter travel saves time and work, as well as wear on valve parts.


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Maintenance is relatively easy with globe valves. The seats and discs are plugs, and most globe valves can be repaired
without actually removing the valve from the pipe.

f) Control Valves

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Control valves are sized and selected to optimize application. Valves that are sized too small will not
pass the required flow. Control valves that are sized too large or are arbitrarily sized to match the
connecting pipe, will result in increased capital costs, decreased valve life (due to the closed position),

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and decreased performance (by limiting range ability). Control valves are optimally then calculating an
expected flow coefficient and the maximum allowable pressure drop. These factors are then compared
to manufacturers data for specific valve types and sizes.

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To select a control valve, the process application must be understood. Minimum information
considered includes desired flow characteristics; type, temperature, viscosity, and specific gravity of
the liquid; minimum and maximum flow capacity; minimum and maximum valve inlet pressure; and
minimum and maximum valve outlet pressure.

General
For liquid piping systems, valves are the controlling element. Valves are used to isolate equipment and piping systems,
regulate flow, prevent backflow, and regulate and relieve pressure. The most suitable valve must be carefully selected for the
piping system. The minimum design or selection parameters for the valve most suitable for an application are the following:
size, material of construction, pressure and temperature ratings, and end connections. In addition, if the valve is to be used for
control purposes, additional parameters must be defined. These parameters include: method of operation, maximum and
minimum flow capacity requirement, pressure drop during normal flowing conditions, pressure drop at shutoff, and maximum
and minimum inlet pressure at the valve. These parameters are met by selecting body styles, material of construction, seats,
packing, end connections, operators and supports.

I) Body Styles
The control valve body type selection requires a combination of valve body style, material, and trim considerations to allow for
the best application for the intended service.

Valve body styles have different flow characteristics as they open from 0 to 100%. The flow rate through each type or body
style will vary according to different curves with constant pressure drops. This is referred to as the valve flow characteristics. A
quick opening flow characteristic produces a large flow rate change with minimal valve travel until the valve plug nears a wide
open position. At that point, the flow rate change is minimal with valve travel. A linear flow characteristic is one that has a flow
rate directly proportional to the flow rate just prior to the change in valve position. Equal increments of valve travel result in
equal percentage changes to the existing flow rate. That is, with a valve nearly closed (existing flow rate is small), a large valve
travel will result in a small flow rate change, and a large flow rate change will occur when the valve is almost completely open,
regardless of the amount of valve travel.

The purpose of characterizing control valves is to allow for relatively uniform control stability over the expected operating range
of the piping system. A design goal is to match a control valve flow characteristic to the specific system. Table-1 illustrates
some typical flow characteristic curves for control valves.

There are exceptions to these guidelines and a complete dynamic analysis is performed on the piping system to obtain a
definite characteristic. Quick opening valves are primarily used for open/close applications (or on/off service) but may also be
appropriate for applications requiring near linear flow. For processes that have highly varying pressure drop operating
conditions, an equal percentage valve may be appropriate.


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II) Material of Construction

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The selection of valve body material and trim material is typically based on pressure, temperature, corrosive and erosive
properties of the liquid. Table-2 provides basic information on typical cast able materials used for control valve bodies.
Certain service conditions require other alloys and metals to withstand corrosive and erosive properties of the liquid. The

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materials that can be used for these situations are similar to the piping materials. The use of non-standard materials is
much more expensive than the use of standard valve body materials.

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III) Seats
Valve seats are an integral part of a valve. The materials for valve seats are specified under valve trim for each valve. As

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such, valve seats are manufacturer specific and should not interchange. Seat material is selected for compatibility with
the fluid. Valve seats can be either metallic or non-metallic. Page no. 54 provides general information for elastomers used
in valve seats.

100

80
g
in
en
op
ck
ui
Q
Percentage of Maximum Flow

60
r
ea
Lin
e
tag
40 c en
Per
u al
Eq

20

0
0 20 40 60 80 100
Percentage of Rated Travel


Recommended Flow Characteristics
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Table 1
Control Syetem Application Recommended Flow Characteristic

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Liquid Level Constant Pressure Linear

Liquid Level Decreasing pressure with increasing flow Linear

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Liquid Level Decreasing pressure with increasing flow Equal Percentage

Liquid Level Increasing pressure with increasing flow Linear

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Liquid Level Increasing pressure with increasing flow Quick Opening

Flow Measurement signal proportional to flow;

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valve in series with measurement device;

wide range of flow required. Linear

Flow Measurement of signal proportional to flow;


small range of flow required with large

pressure change for increasing flow. Equal Percentage


valve in parallel (bypass) with measurement

device; wide range of flow required. Linear


valve in parallel (bypass) with measurement device;

small range of flow required with large

pressure change for increasing flow Equal Percentage

Flow Measurement signal proportional to flow squared;


wide range of flow required. Linear

Flow Measurement signal proportional to flow

squared; valve in series with measurement device;

small range of flow required with

large pressure change for increasing flow EqualPercentage


valve in parallel (by pass) with

measurement device; wide range of flow

required. Equal Percentage


valve in parallel (bypass) with

measurement device; small range of flow

required with large pressure change for

increased flow Equal Percentage

Pressure All Equal Percentage


Standard Control Valve Body Materials
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Table 2

Cast Material Standard Comments

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Carbon Steel ASTM A 216 Gr. WCB Moderate services such as non-corrosive liquids.
Higher pressures and temperatures than cast iron.
Check codes for suitability at extended high temperatures.

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Chrome-Moly Steel ASTM A 217, Gr. C5 Used for mildly corrosive fluids such as sea water, oils,
resistant to erosion and creep at high temperatures. Can be
used to 595 C (1,100 F).

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Type 304 Stainless Steel ASTM A 351, Gr. CF8 Used for oxidizing or very corrosive fluids Can be used above
540 C (1,000 F).

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Type 316 Stainless Steel ASTM A 351, Gr. CF8M Used for oxidizing or very corrosive fluids, resistant to
corrosion pitting and creep provides greater strength than 304
S.S.

Monel ASTM A 494Gr. M35-1 Resistant to non oxidizing acids. Used with seawater and other
mildly corrosive fluids at high temperatures. Expensive
material.

Hastelloy-C ASTM A 494 Gr. CW2N Used particularly with chlorine and chloride compounds.
Expensive material.

Iron ASTM A126 Class B Inexpensive and non-ductile, used for water and non-corrosive
liquids.

Bronze ASTM B 61 AND B 62 ASTM B 61 typically used for trim. ASTM B 62 typically used
for valve body. Can be used for water and dilute acid service

In addition, the amount of valve leakage is determined based on acceptability to process and design requirements.
Control valve seats are classified in accordance with ANSI for leakage. These clasifications are summarized in Table 4
and Table 5.

Table 4 Table 5
Valve Seat Leakage Classifications Class VI Allowable Leakage
Leakage Class Maximum Allowable Leakage Nominal Port Allowable Leakage
Designation Diameter Rate
I — mm (in) (ml per minute)
II 0.5% of rated capacity 0.15
25 (1)
III 0.1% of rated capacity
38 (1½) 0.30
IV 0.01% of rated capacity
51 (2) 0.45
V 5 x 10-12 m3/s of water per
64 (2½) 0.60
mm of seat diameter per bar
differential 76 (3) 0.90

VI Not to exceed amounts shown 102 (4) 1.70
in Table 5 based on seat 152 (6) 4.00
diameter) 203 (8) 6.75

IV) Packing
Most control valves use packing boxes with the packing retained and adjusted by flange and stud bolts. Several packing
materials are available for use, depending upon the application. Table 6 provides information on some of the more typical
packing arrangements


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V) End Connections

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The common end connections for installing valves in pipe include screwed pipe threads, bolted gasket flanges, welded
connections, and flangeless (or wafer) valve bodies.

Screwed end connections are typically used with small valves. Threads are normally specified as tapered female National

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Pipe Thread (NPT) and BSP connection are available in standard. This end connection is limited to valves 50 mm (2 in) and
smaller and is not recommended for elevated temperature service. This connection is also used in low maintenance or non-
critical applications.

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Flanged end valves are easily removed from piping and, with proper flange specifications, are suitable for use through the
range of most control valve working pressures. Flanges are used on all valve sizes larger than 50 mm (2 in). The most

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common types of flanged end connections are flat faced, raised faced, and the ring joint. Flat faced flanges are typically used
in low pressure, cast iron or brass valves and have the advantage of minimizing flange stresses. Raised faced flanges can be
used for high pressure and temperature applications and are normally standard on ANSI Class 250 cast iron and on all steel
and alloy steel bodies. The ring type joint flange is typically used at extremely high pressures of up to 103 MPa (15,000 psig)
but is generally not used at high temperatures. This type of flange is furnished only on steel and alloy valve bodies when
specified.

Welding ends on valves have the advantage of being leak tight at all pressures and temperatures; however, welding end valves
are very difficult to remove for maintenance and/or repairs. Welding ends are manufactured in two styles; socket and butt.

Flangeless valve bodies are also called wafer-style valve bodies. This body style is common to rotary shaft control valves such
as butterfly valves and ball valves.

Table 6 : Packing
Type Application

PTFE Resistant to most chemicals. Requires extremely smooth stem finish to seal properly.
Will leak if stem or packing is damaged.

Laminated/Filament Graphite Impervious to most liquids and radiation. Can be used at hightemperatures, up to
0 0
650 C (1,200 F). Produces high stem friction.
0 0
Semi-Metallic Used for high pressures and temperatures, up to 480 C (900 F)
0 0
Fiberglass Good for general use. Used with process temperatures up to 288 C (550 F). Ferrite
steel stems require additive to inhibit pitting.
0 0
Kevlar and Graphite Good for general use. Used with process temperatures up to 288 C (550 F).
Corrosion inhibitor is included to avoid stem corrosion.

Flangeless bodies are clamped between two pipeline flanges by long through-bolts. One of the advantages of a wafer-style
body is that it has a very short face-to-face body length.

vi) Operators
Valve operators, also called actuators, are available in manual, pneumatic, electric, and hydraulic styles.

Manual operators are used where automatic control is not required. These valves may still result in good throttling control, if
control is necessary. Gate, globe and stop check valves are often supplied with hand wheel operators. Ball and butterfly
valves are supplied with hand levers. Manual operators can be supplied with direct mount chain wheels or extensions to
actuate valves in hard-to reach locations. Manually operated valves are often used in a three-valve bypass loop around control
valves for manual control of the process during down time on the automatic system. Manual operators are much less
expensive than automatic operators.


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For sliding stem valves, that is, valves that are not rotary, the most common operator type is a pneumatic operator.
A pneumatic operator can be a spring and diaphragm type or a pneumatic piston. While these pneumatic operators are also

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available for rotary shaft valves, electrical operators tend to be more common on the rotary valves.

Spring and diaphragm operators are pneumatically operated using low pressure air supplied from a controller position or other

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source. Styles of these operators include direct acting, in which increasing air pressure pushes up the diaphragm and extends
the actuator stem; reverse acting, in which increasing air pressure pushes up the diaphragm and retracts the actuator stem;
and direct acting for rotary valves. Pneumatic operators are simple, dependable, and economical. Molded diaphragms can be

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used to provide linear performance and increase travel. The sizes of the operators are dictated by the output thrust required
and available air pressure supply.

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Pneumatic piston operators are operated using high pressure air. The air pressure can be up to 1.03 MPa (150 psig), often
eliminating the need for a pressure regulator that is required on a diaphragm actuator. The best design for piston actuators is
double acting. This allows for the maximum force in both directions on the piston. Piston actuators can be supplied with
accessories which will position the valve in the event of loss of air supply. These accessories include spring return, pneumatic
trip valves, and lock-up type systems. It is common to include manual operators along with pneumatic piston operators in a
design. These manual operators can then act as travel stops to limit either full opening or full closing of the valve.

Electric and electro-hydraulic operators are more expensive than pneumatic actuators; however, they offer advantages

When no existing air supply source is available, where low ambient temperatures could affect pneumatic supply or where very
large stem forces of shaft forces are required. Electrical operators only require electrical power to the motors and electrical
input signal from the controller in order to be positioned. Electrical operators are usually self- contained and operate within
either a weather-proof or an explosion-proof casing. An auxiliary positioner or booster is sometimes used on pneumatic
operating systems when it is necessary to split the controller output to more than one valve, to amplify the controller above the
standard range in order to provide increased actuator thrust, or to provide the best possible control with minimum overshoot
and fastest possible recovery following a disturbance or load change. Determination of whether to use a positioner or a
booster depends on the speed of the system response. If the system is relatively fast, such as is typical of pressure control and
most flow control loops, the proper choice is a booster. If the system is relatively slow, as is typical of liquid level, blending,
temperature and reactor control loads, the proper choice is a positioner.

Hydraulic snubbers dampen the instability of the valve plug in severe applications and are used on pneumatic piston and direct
acting diaphragm actuators.

Limit switches can be used to operate signal lights, solenoid valves, electric relays, or alarms. The limit switches are typically
provided with 1 to 6 individual switches and are operated by the movement of the valve stem. It is common for each switch to
be individually adjustable and used to indicate the full open or full closed position on a valve.

Electro-pneumatic positioners are used in electronic control loops to position pneumatically operated control valves. The
positioner or transducer receives a current input signal and then supplies a proportional pneumatic output signal to the
pneumatic actuator to position the valve.

vii) Supports

Specific pipe material design recommendations are followed when designing supports for valves. In general, one hanger or
other support should be specified for each side of a valve, that is, along the two pipe sections immediately adjacent to the valve.
The weight of the valve is included in the calculation of the maximum span of supports.


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Table - 8 Common Globe Valve Seating

Type Comments

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Plug Long taper with matching seat provides wide seating contact area. Excellent for severe throttling
applications. Resistant to leakage resulting from abrasion. With proper material selection, very
effective for resisting erosion.

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Conventional Disc Narrow contact with seat. Good for normal service, but not for severe throttling applications.
Subject to erosion and wire drawing. Good seating contact if uniform deposits (such as from

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coking actions) occur. Non-uniform deposits make tight closure difficult.

Composition Disc “Soft” discs provided in different material combinations depending upon liquid service. Good for
moderate pressure applications except for close throttling, which will rapidly erode the disc.

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Needle Sharp pointed disc with matching seat provides fine control of liquid flow in small-diameter piping.
Stem threads are fine, so considerable stem movement is required to open or close.

General Usage Information

A. SYNTHETIC RUBBER MATERIALS:

Buna N:
Standard compound for service in petroleum, oils, air, water, mild acids, acetylene, kerosene's, lime solutions, liquefied
petroleum gases and turpentine's. Not recommended for high aromatic gasolines or acids.

Silicone:
Known as the only elastomer which under certain conditions can be utilized for both high and low temperature. This is its
principal usage. Also handles hydrogen peroxide and some acids. Not good for steam. Very good disc life. Fluoro-silicone
compounds noted to have better fuel resistance.

Neoprene:
Principally used in refrigeration systems [Freon 22] as an external seal. Neoprene is also utilized for oxygen service.
Suitable for alcohols, mild acids, water, air ammonia, argon gas, and other gases.

Urethane:
Used for water, air at normal ambient temperatures, alcohols, non-aromatic compounds, ether, edible fats and oils, and
hydraulic fluids. Its principal asset is high strength, excellent abrasion resistance. It is not recommended for Ketones, and
strong oxidizing agents.

Viton:
Suitable for temperatures some what above the Buna N range. Excellent resistance to many petroleum oils, gasoline, dry
cleaning fluids and jet fuels. Not good for Ketones, halogenated hydro carbons and Freon's.

Hypalon:
Used to handle strong oxidizing fluids, edible liquids, many chemicals etc. Not recommended for aromatic or chlorinated
hydro carbons.

Ethylene Propylene:
Suitable for temperatures somewhat above the Buna N range. Features similar to butyl [i.e. excellent for phosphate ester
type fluids and poor on petroleum base types] except ethylene have a somewhat higher temperature range than butyl. On
this basis, ethylene propylene has served to replace the formerly used butyl. Useful 'O' ring gaskets on steam valves due
to low compression set. Ethylene propylene is generally suitable for most photographic solutions as well as numerous
chemical solutions.


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B. PLASTICS:

Celcon, Derlin:

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Acetyl resin type thermoplastics which are extremely rigid but not brittle. They provide good toughness, tensile strength,
stiffness and long fatigue life. They are odorless, tasteless, non toxic, and resistant to most solvents. Celcon is noted to

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have some what better heat stability than Derlin.

Lexan:

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A polycarbonate type thermoplastic known for having high impact strength and good resistance to inorganic acids and
aliphatic hydrocarbons. Not suitable for use with air containing Phosphate esters [found in synthetic oils].

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Nylon:
A polyamide resin known to be very durable and also resistant to many chemicals. Heat resistant type nylon is always
employed in valves.

Polysulfone:
Known as one of the most heat resistant of the thermoplastics. It has excellent chemical resistance when used for
inorganic acids, alkalis and aliphatic hydrocarbons.

Teflon:
A fluro carbon resin known to be suitable for disc material where all other synthetic materials have failed. Teflon is not
easily fabricated and is known to have objectionable "cold flow" characteristic. Rulon is a form of Teflon having filters
which have been added for improved mechanical properties.

Polyvinyl chloride [PVC]:
Known for its chemical inertness but has somewhat less temperature resistance than most other plastics. PVC has
excellent resistance to strong alkalis, mineral acids, salts and many chemicals which are corrosive to conventional
materials.

Polypropylene:
A thermoplastic known to have excellent resistance to inorganic salts, mineral acids and gases. It offers good resistance to
photographic solutions and is one of the few plastics that have the ability to withstand steam sterilization.

Polyphenylene sulfide:
Has outstanding chemical resistance. It has no known solvents at temperatures below 4000F. It has low friction, good wear
resistance and high tensile strength.

NOTE:
Generally plastics utilized as pressure containing members are not suited for any significant temperature range such as
can be expected from metallic materials due to brittleness at low temperature and softening with subsequent strength loss
at high temperature. Specific temperature limits can be obtained from the individual bulletin section of the Sude catalog.

C. METALS:

Aluminum:
Shading coil material for special fluids or for making washers etc. die cast aluminum is generally used for bodies for low
pressure gas valves and can only be used with 'water free' installations. It can be noted that die cast aluminum has been
successfully utilized for oil and gasoline application.


SUDE
Brass:
Forging brass is used in our body forgings. Forging brass conforms to ASTM B 283 and has a composition of 59% copper,

E
2% lead and 39% zinc.

Copper:

D
Primarily used as shading coil.

Inconel:

U
Used for high temperature springs such as steam applications and special designs.

Iron:

S
Cast iron bodies.

Lead:
Gaskets sometimes lead clad copper gaskets.

Monel:
Core tube material to handle fluids corrosive to standard austenitic Stainless steel

49 Nickel Iron:
Core material for low temperature fluids [below minus 1500F used for long stroke solenoid.

Silver:
Shading coil material for stainless steel valves.

Austenitic [300 series Stainless steel]:
Bodies, springs, core tubes etc. This material is also known as an 18-8 alloy, i.e. 18% chromium, 8% nickel.

430F Magnetic stainless steel:
Core and plug nut materials, basic composition 18% chromium, and remainder iron.

D. TERMINOLOGY:

Concentration:
The data given in this guide is based mainly on concentrated fluids unless otherwise indicated. A diluted fluid or solution is
not necessarily less corrosive than a fluid of 100% concentration. It would be quite complicated to list all the variations
and, therefore, caution must be used and good judgment applied.

Temperature:
Generally as the temperature increases the corrosive action of the fluid usually increases. The guide is based on fluid
temperature to a maximum of 2000F for metals and elastomers except for urethane which is limited to 1400F on gaseous
media and 750F on media containing water. Consult Sude for temperature ratings of plastic valves or a particular bulletin,
which may be limited to factors other than materials.


SUDE
Swell of Synthetics:

E
Basically, elastomers fail due to excessive swelling thereby contributing to reduced flows notably on short stroke valves.
Along with swelling some softening and loss of tensile properties also occur. In view of this, the elastomer rating in the
guide in most cases is based on a maximum volumetric swell of 5-8%. Elastomer stiffening can also occur if the media

D
extracts plastizers.

Heavy or Viscous Fluids:

U
Fluids such as syrups, glue, grease, etc., will generally require auxiliary operated or manually operated valves.
Furthermore, in some cases, a frequent or daily flushing is required to keep the valves in operative condition. Most valves
are limited to 300 SSU fluids except where indicated in the catalog. Applications past this range should be referred to

S
Sude Sales as pressure ratings, operational speeds, etc. are somewhat affected depending on particular bulletin.

Organic Acids:
Basically are derived from living materials and always contain carbon and usually hydrogen along with other elements.
Included in this group are the fatty acids, the name originating from the fact that several of them occur in large quantities in
natural fats and oils. This group includes acidic, lactic, citric, etc.

Inorganic Acids:
Basically are derived from inanimate materials. They are also known as the mineral acids and include such common acids as
hydrochloric, hydrofluoric, carbonic, chromic, nitric, phosphoric, and sulfuric.

Alkaline Solutions:
Are strong bases (Alkalis) and commonly exist as sodium hydroxide, calcium hydroxide, potassium hydroxide, etc. Sodium
hydroxide is sometimes referred to as caustic soda.

Aliphatic Hydrocarbon:
Series of organic compounds in which the carbon atoms are arranged in an open chain. Some of the most common fluids in this
area are the Freon's, perchloro ethylene, and trichloroethylene.

Aromatic Hydrocarbon:
Hydrocarbons found in coal tar which are so designated because of their aromatic odor. Basically these include the well known
solvents benzene, toluene, and xylene.

Chlorinated Hydrocarbons:
A hydrocarbon in which one or more of the hydrogen atoms has been replaced by chlorine. Example: Perchloroethylene.

Ketones:
A class of liquid organic compounds primarily used as solvents in paints, etc. Typical Ketones are acetone and Methyl Ethyl
Ketone (MEK).

Phosphate Esters:
Generally refers to a type of fire resistant synthetic hydraulic fluid or lubricant known by the trade name.


SUDE
Oxidizing Fluid:

E
An oxidizing medium consists of a fluid which is oxygen containing and thus has the ability to provide and maintain a stable
protective oxide film on the surface of a metal.

D
pH Factor:
In its simplest definition, it is merely a means of designating the degree of acidity or alkalinity of a fluid. A neutral fluid would

U
have a pH of 7 which is typical of most drinking water. Any number below 7 is in the acid zone with its degree of acidity
increasing as the number decreases downward from 7. Likewise any number upward from 7 approaching 14 is a measurement
of the degree of alkalinity.

Degree of Water Purity:

S
Three types of impurities must be taken into account.

(1) Dissolved unionized matter which consists of organic substances and some gases.

(2) Particulate matter which includes colloids, bacteria and other suspended matter.

(3) Dissolved ionized matter which consists mainly of inorganic salts and acids and some gases.

Removal of (1) produces demineralized water. Removal of (1) and (2) produces distilled water, and removal of (3) produces
deionized water.

Distilled, demineralized, and deionized waters normally do not cause corrosion but must not be permitted to be contaminated
by metals and elastomers such as brass and Buna “N” which would affect their purity.

Demineralized Water:
Water which has impurities removed by means of ion-exchange. This is accomplished by a resin treatment process which
removes metallic impurities such as calcium, sodium magnesium copper, etc. i.e. the unionized matter. Remaining dissolved
solids are normally kept below 1000 PPM.

Distilled Water:
Approaches absolute purity and has a higher degree of purity than demineralized water as both unionized particulate
matter have been removed. Somewhat costly to produce as distillation requires and involves the use of considerable
quantities of heat as well as a large amount of process cooling water to condense the distilled water from steam.

De-ionized Water:
Water which is free of dissolved ionizable impurities only. Produced by various ion-exchange methods.

Liquefied Petroleum Gas:
Known as LPG. It is a compressed or liquefied gas obtained as a by-product in petroleum refining or natural gas
manufacture. It usually consists of a pure propane and butane mixture.

Natural Gas:
Mixture whose major constituent is methane. Also contains some ethane and small amounts of propane and butane.


SUDE
Manufactured Gas:
Produced from coal, coke, or petroleum products and contains approximately 2/3 methane and 1/3 carbon monoxide.

Sour Gas:

D E
Term applied to natural gas which is contaminated with a sulfur compound, usually hydrogen sulfide.

Sewage Gas:

U
Also known as digester or garbage gas and is a gaseous by-product from sewage treatments. Product of fermentation
consisting mainly of 2/3 methane and 1/3 carbon dioxide. Normally contains sufficient amounts of moist hydrogen sulfide

S
to cause corrosion problems.

Flue Gas:
Mixture of gases resulting from combustion and other reactions in a furnace passing off through a smoke flue. Contains
largely nitrogen, carbon dioxide, carbon monoxide, water vapor and often sulfur dioxide.

E. CORROSION CAUSES AND MEANS OF CONTROL:

Corrosion is nature's way of reverting the fine metals to their natural state and thereby undo man's “meddling” with ores. It is
virtually impossible to completely eliminate corrosion, but understanding its nature can help to drastically reduce its effects.
Most corrosion takes place in the presence of moisture to some degree either through atmospheric contact or in handling
aqueous media.

TYPES:
Direct Chemical Attack Usually uniform and most commonly characterized by the ability of the corroding media to dissolve and
wash away the protective oxide film which most metals form when exposed to an oxidizing media.

Galvanic or Electrochemical Usually localized and is a more complicated form which can exist if two dissimilar metals are in
contact by means of an electrolyte (conductive solution) which normally is a liquid of some form.


Chemical Resistance Chart
SUDE

CHEMICAL RESISTANCE GUIDE FOR THERMOPLASTIC VALVES, PIPE & FITTINGS
ELASTOMERS AND METALS MAX. TEMP. IN (0F)

CONCENTRATION
E

CARB.STEEL
NEOPRENE
D
HYPALON

TITANIUM
400 S.S.

316.S.S.
BRASS
CHEMICAL &

VITON
EPDM

BUNA
CPVC

PVDF
PVC

TFE
PP
FORMULAS

Acetaldehyde
CH2CHO

Acetic Acid
CH2COOH

Acetic Acid
CH2 COOH
Conc.

0.25

0.6
A
X

140
A

73
A

S
X

73

73
A
U 100
A

140
A

--
X

200
A

175
A
350
A

350
A

350
A
200
A

140
A

140
A
X

140
A

140
A
70
A

200
A

200
A
A
X

160

160
A
X

100
C

70
C
X

X

X
A

X

X
C

A

A
A

A

A
A

A

A

Acetic Acid 73 120 150 350 140 70 200 160 X
0.85 X X X A A A
CH2COOH A A A A A A A A

Acetic Anhydride 73 350 X -- 200 73 C
(CH2 OCH2) -- X -- -- X X X C C
A A A C

Acetone 73 350 70 70
CH2COCH2 X X X X X X X A A A A A
A A A C

Aluminum Acetate 160 175 170 275 350 200 70 70
Al(C2H2O2)2 X X C A A
A A A A A A C C

Aluminum Chloride 185 185 180 280 250 210 250 200 160 70
Aqueous AlCl2 X X X A A
A A A A A A A A A A

Aluminum Fluoride 73 185 180 280 250 210 250 200 160 180
Anhydrous AlF2 X C X
A A A A A A A A A A

Aluminum Sulfate 140 185 180 280 250 210 185 160 140 200
X X X C A
(Alum) Al2(SO4)3 A A A A A A A A A A

Ammonia Gas 140 185 150 400 140 140 140 140
1 X X X A A A A
(Dry) NH3 A A A A A A A A

Ammonia Liquid 73 400 210 70 70 70
1 X X X X X A A A A
NH3 A A A A A C

Ammonium Carbonate 140 185 180 280 400 210 250 140 140 140
X A C C C
(NH2)HCO2(NH2)CO2NH3 A A A A A A A A A A

Ammonium Chloride 140 185 180 280 400 210 250 200 160 180
X X X C X
NH4Cl A A A A A A A A A A

Ammonium Hydroxide 0.1 140 185 180 225 400 210 70 200 200 70
X X C A A
NH 2OH A A A A A A A A A C

A - RECOMMENDED, C - CONDITIONAL, X - NOT RECOMMENDED,

TO USE THIS CHART AS GUIDE ONLY, CONSULT SUDE/SDTORK FOR VALVE MATERIAL SELECTION.


Chemical Resistance Chart
SUDE

CONCENTRATION

CARB.STEEL
E
NEOPRENE
HYPALON

TITANIUM
400 S.S.

316.S.S.
BRASS
CHEMICAL &

VITON
EPDM

BUNA
CPVC

PVDF
PVC

TFE
PP
FORMULAS

Ammonium Nitrate
NH4NO3

Ammonium Persulphate
(NH4)2S2O2
140
A

140
A
185
A

73
A

U
180
A

150
A
280
A

73
A
400
A

200
A
250
A

140
A
300
A

70
A
200
A

70
A D 160
A

70
A
180
A

70
A
X

X
X

X
C

C
A

C
A

A

S
Ammonium Sulphate 140 185 180 280 400 210 200 140 160 180
X X C C A
(NH4)2SO4 A A A A A A A A A A

Ammonium Sulfide 140 140 140 140 350 210 200 200 160 140
X X X C A
Dilute A
(NH4)2S A A A A A A A A A

Amyl Acetate 100 125 100 70 70 70
X X X A A A
X X X X
CH 2COOC2H11 % A A C A C

140 140 180 280 400 210 185 140
Amyl Alcohol C5H11OH 100% A C A A A
A A A A A A A C

n-Amyl Chloride 280 400 200
X A A A A A
100% X X X X X X
CH2(CH2)2CH2Cl A A A

Aniline 180 120 200 140 140
X X X X C X
100% X X X X
C4H6NH2 A A A A A

Aniline Hydrochloride 75 185 200
X X X X X
X X X
C4H2NH2HCl A A A

Anthraquinone 140 200
X X
C4H6(CO) 2C4H6 A A

Antimony Trichloride SbCl2 140 180 73 200 140 185 140 140
X X X X X X
A A A A A A A A

Arsenic Acid 140 185 160 280 400 250 200 200 180 160
80% X X C A C
H2ASO4½H2O A A A A A A A A A A

Asphalt 250 350 180 70
X X X X X X A A A A A
A A A C

Barium Carbonate 140 160 150 280 400 250 300 200 160 180
A C A A A
BaCO3 A A A A A A A A A A

Barium Hydroxide 140 160 150 280 400 250 300 140 180
X X X A A A
Ba(OH)2 A A A A A A A A A

Barium Sulphate 140 185 150 280 400 250 300 200 160 100
C A A A A
BaSO4 A A A A A A A A A A

Barium Sulphide 140 160 150 280 400 140 300 200 160
X X X A A A
BaS A A A A A A A A A

Beer 140 160 180 200 300 200 200 140 140
X A X A A A
A A A A A A A A A

Benzaldehyde 140 73 73 70 140
X A X A A A
0.10% -- X X X
C6H2CHO A A A A A

Benzene 170 250 185
X A A A A A
X X X X X
C6H8 A A A

A - RECOMMENDED, C - CONDITIONAL, X - NOT RECOMMENDED


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