Guide to-choosing-the-right-valve

1. A GUIDE TO CHOOSING THE
RIGHT VALVE
FOR HYGIENIC APPLICATIONS
eBOOK

2. .INTRODUCTION....................................................................................................................................................................3
VALVE COMPONENTS.......................................................................................................................................................3
TYPES OF VALVES...............................................................................................................................................................4
Ball Valves..................................................................................................................................................................................4
Plug Valves............................................................................................................................................................................5–6
• Lubricated.............................................................................................................................................................................6
• Non-Lubricated....................................................................................................................................................................6
• Eccentric................................................................................................................................................................................6
• Expanding.............................................................................................................................................................................6
Shutter Valves...........................................................................................................................................................................7
Butterfly Valves.........................................................................................................................................................................8
Seat Valves.................................................................................................................................................................................9
Mixproof Valves......................................................................................................................................................................10
Air Blow Check Valves........................................................................................................................................................... 11
VALVE MANIFOLDS........................................................................................................................................................... 12
Automation and Controls...............................................................................................................................................12–13
Summary................................................................................................................................................................................... 13
NOTES..................................................................................................................................................................................14–15
TABLE OF CONTENTS
VALVE BUYING GUIDE
2

3. INTRODUCTION
In a process piping system, valves are devices that
stop, divert, or control the flow of a fluid (gases,
liquids, or slurries) by opening, closing, or partially
obstructing a passageway. Valves function in a
number of different ways. They are used to start and
stop a fluid flow, control the direction of the flow,
and vary its amount, depending on the nature of the
mechanical barrier used in the valve (a plate, a ball,
or a diaphragm). Valves are also used to regulate
a system or process, and relieve overpressure
situations in a process line.
Valves are used extensively in process industries
such as pharmaceutical manufacturing and food &
beverage processing and choosing the correct type
of valve for a particular application is important. The
simplest valves are operated manually, activated via
a handle, lever, pedal, or wheel. More sophisticated
valves or valve systems, though, are activated
automatically, responding to changes in pressure,
temperature, or flow in the process piping.
In determining the correct type of valve to use for your
application, there are a number of considerations
to take into account. First is the process media,
that is, the nature of the fluid which is flowing
through the process piping (e.g., milk, yogurt, etc.).
Considerations can include whether the materials
are corrosive or abrasive, their viscosity, the desired
flow rate, particle size (if a slurry), and so on. Next to
be considered is the process system’s temperature
and pressure. Then, one needs to think about the
valve’s application and function. For example, does
the valve just need to start and stop the fluid flow,
or will it be used to regulate or throttle? How much
leakage, if any, can be tolerated? And, how precise
does the valve need to be? Maintenance also needs
to be taken into account, that is, how often the valve
needs to be cleaned or serviced.
Next, the material from which the valve is
constructed needs to be considered. Sanitary
processing industries such as the food, beverage,
and dairy industries may require that valves be
made of high purity metals such as 316L stainless
steel, and meet hygienic standards imposed by
industry standards organizations such as 3-A. (3-A is
an independent, not-for-profit corporation dedicated
to advancing hygienic equipment design used in
the food & beverage industries). For example, for
clean-in-place (CIP) and clean-out-of-place (COP)
applications, the valves controlling the fluid flow
in the process pipelines used in sanitary industries
may need to be 3-A certified. Then, there are safety
standards to be considered. The pharmaceutical
and chemical processing industries in particular may
require that valves comply with the safety standards
associated with the materials from which they’re
made. Considerations here can include constructing
valves of non-reactive materials, the operating
pressure and temperature of the piping system, and
the leakage of potentially hazardous materials.
VALVE COMPONENTS
Allvalvestypicallycontainthefollowingcomponents:
• A body, which contains the internal parts.
• A port, which allows the fluid to pass through
the valve.
• A handle (if a manually-controlled valve) or an
actuator (for automatically-controlled valves).
• A stem, which transmits motion from the handle
or the valve’s controlling device to form a leak-
proof seal.
• A disc or similar valve component that serves as
a moveable obstruction to adjust the flow of the
fluid through the valve.
• And finally, a seat, which is the interior surface
of the body that contacts the disc to form a leak-
tight seal.

4. DISADVANTAGES
• Lacks fine control. Really just suitable for
on/off applications, not fluid throttling or
flow regulating.
• Not a sanitary valve. Product can become
trapped in the ball area when the valve
is closed.
• Cannot be cleaned using CIP methods.
ADVANTAGES
• Compact, durable, and reliable.
• Requires little maintenance.
• Relatively inexpensive in comparison to
other valves.
• Comparatively leak-proof.
• Opens and closes relatively quickly
(depending on the type of actuator)
• Suitable for high temperature and high
pressure applications (up to 700 bar
pressure and 200 degrees Celsius).
ADVANTAGES & DISADVANTAGES
OF BALL VALVES
BALL VALVES
How it works: Ball valves control the flow of a
material or substance from one opening to the next.
These are quarter-turn valves that use a hollow,
perforated, and pivoting ball to control the flow of
fluid through the valve. The valve is open when
the valve’s hole is in-line with the fluid, and closed
when the ball is rotated 90 degrees by turning the
valve’s handle.
There are a couple of variations on ball valves that
may be used for specialized applications. There are
3-way ball valves on the market, for example, that
can be used as flow divert valves. These are popular
because they provide a simple and economical
method to provide both shutoff and flow direction
control in a single valve body.
There’s also a valve called a characterized ball
valve that features a V-notch in the ball itself. These
particular valves provide a more precise flow control
compared to standard ball valves. The v-shape in
the ball enables the valve to convert to a modulating
control ball valve.
Used for: Water, clean or 3-A air, culinary steam,
and in food & beverage processing, non-viscous
fluids not requiring CIP cleaning (e.g., vinegar, some
sugars). Can be used with corrosive fluids and a
wide variety of gases, as are typically found in the
oil and natural gas industries.
Construction: Stainless steel, brass, bronze, chrome,
titanium, PVC, CPVC, and many other materials.
TYPES OF VALVES
VALVE BUYING GUIDE
4

5. DISADVANTAGES
• Requires greater force to actuate, due to
high friction. Additionally, every time you
turn the valve, there’s wear and tear on
the plug.
• More expensive than ball valves, both to
purchase and maintain.
• Prone to leaks.
• Can harbor bacteria in the plug and body
due to scarring.
• Can only be cleaned using out-of-place
cleaning methods. This is not a CIP’able
valve.
ADVANTAGES
• A simple valve, with few parts.
• Quick to open and close.
• Offers minimal resistance to flow.
• Does not cause a lot of pressure build-up
in the process line.
• This is a repairable type of valve. The plug
may be replaced or recoated.
• When constructed of the appropriate
materials (e.g., 316L stainless steel),
considered to be a sanitary (hygienic)
valve by both the 3-A and the EHEDG
(European Hygienic Engineering &
Design Group).
PLUG VALVES
How it works: Plug valves are an older-design ¼
turn valve that use a conically-shaped “plug” that
rotatesinsidethevalve’sbodytocontrolthefluidflow
through the valve. These are manually-activated,
relatively simple valves. The 2-port model is the
most common, with open and closed positions. In
food & beverage processing applications, they are
extremely easy on viscous products such as peanut
butter.
Used for: A common valve found widely throughout
dairy plants, where they are often used in batch
pasteurization tanks where products are heated up
and then cooled down. Additionally, used in steam,
oil, gas, and chemical flow applications when a
quick shutoff is required. Not generally designed for
the regulation of flow. Suitable for high temperature
(up to 815 degrees C) and high pressure (up to
10,000 PSI) applications. These valves perform well
in slurry applications.
ADVANTAGES & DISADVANTAGES
OF PLUG VALVES

6. PLUG VALVES CONTINUED
Although there are many different types of plug
valves, there are four general categories, each with
their own benefits:
Lubricated plug valves use a lubricant usually made
up of a base oil and a viscosity improving agent
(such as amorphous or fumed silica) that is injected
under pressure between the plug face and body
seat to reduce friction and seal the ports. Valve
manufacturers generally recommend lubricants
that are suitable to a particular process fluid. These
types of valves must often be resealed after only a
few cycles of use, and in some cases, after every
cycle. Because of this, they are considered a high
maintenance plug valve, and are often used in
applications requiring infrequent operation. These
types of plug valves perform well in processes that
use fluids carrying mildly abrasive particles (such as
dirty upstream applications), gas pipeline systems
requiring bypass valves, and as blow-down valves
on valve stations and kicker valves.
Non-lubricated plug valves employ a tapered or
cone-shaped plug that acts as a wedge, pressing
a polymeric sleeve against the valve’s body cavity.
The use of the sleeve reduces friction between the
plug mechanism and the body. Non-lubricated plug
valves are often used instead of lubricated ones in
applications where maintenance needs to be kept
to a minimum, such as in applications involving
sulfur, hydrogen fluoride, or where liquids could be
trapped and solidify, potentially jamming the valve.
However, non-lubricated plug valves are limited by
temperature and the chemical compatibility of the
non-metallic materials they’re made of. The three
types of non-lubricated plug valves include lift-type,
elastomer sleeve, and fully lined variants.
TYPES OF VALVES
Eccentric plug valves use a half-plug that is
advantageous for applications requiring a higher
seating force with minimal friction between the open
and closed positions. These torque-seated valves
also provide improved shutoff capabilities. Eccentric
plug valves are used for a wide range of flow control
and isolation applications including clean and dirty
water, sewage, sludges, and slurries.
Expanding plug valves feature multiple components
that allow the valve to mechanically expand, giving
it a true block and bleed capability in one valve. The
plug valve uses a mechanism that rotates between
the open and closed positions and protects both
seals from the flow path. During rotation there
is no contract between the body and seals, and
slips expand onto the body seat when the valve is
closed to avoid any wear or abrasion to the seals.
Expanding plug valves are often used to prevent
product contamination in applications that do not
require a double isolation.
Construction: Depending on the application, can
be made from a variety of metals including steel,
stainless steel, and iron, as well as plastics such
as PTFE.
In conclusion, plug valves have a number of useful
applications, and new technology and designs
are sure to give them an even wider range of
applications within many processes.
VALVE BUYING GUIDE
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7. SHUTTER VALVES
How it works: Shutter valves use a spring washer
system to press a movable shutter against the
cylindrical surface of the valve’s body in order
to close the valve. These ¼ turn valves can be
actuated either manually or automatically, and may
be cleaned using CIP methods. Some of the “New
Age” variants of shutter valves are also “pig-able”,
meaning that you can run a cleaning plug (commonly
called a “pig”) through the body of the valve in order
to push out product.
Used for: Shutter valves are specifically designed
for difficult applications, allowing for the flow of
large particulates and highly viscous fluids. The full-
port nature of these valves minimizes pressure loss
and maximizes gentle product handling. Suitable for
use in the food & beverage processing industry, the
biopharmaceutical manufacturing industry, home
and personal care products manufacturing, and the
chemical processing industries.
Construction: Steel, stainless steel, or alloys. DISADVANTAGES
• A relatively large valve in comparison to
plug valves.
• Cannot be opened and closed quickly.
ADVANTAGES
• Less prone to wear than plug valves
(although erosion and abrasion may occur
at the sealing surface between the shutter
and the valve body).
• A relatively simple design, with a minimum
number of moving parts.
• Due to the relatively slow opening and
closing of this valve, it’s not prone to
water hammer.
• Deemed a sanitary valve by the 3-A for
hygienic processing applications (although
only certain types of shutter valves have
been approved by the EHEDG as well).
ADVANTAGES & DISADVANTAGES
OF SHUTTER VALVES

8. BUTTERFLY VALVES
How it works: Butterfly valves are quarter-turn
valves that employ a disc that rotates around a fixed
point in the valve. When the valve is closed, the disc
is turned so that it completely blocks off the flow of
liquid in the passageway. When the valve is opened,
the disc is rotated ¼ of a turn so that it allows an
almost unobstructed passage of the fluid through
the valve’s body. Butterfly valves can be configured
to operate manually, electronically, or pneumatically.
There are two basic types of butterfly valves:
The lug butterfly valve is similar to a three-piece
ball valve in that one end of the line can be taken
off without having an effect on the other side. As
a result, you don’t need to shut down the entire
system in order to clean, inspect, or repair this type
of butterfly valve
A wafer butterfly valve, in turn, is designed to
safeguard against any bi-directional pressure
differential in systems designed for a uni-directional
flow, thus avoiding any backflow. It does this by using
a tightly-fitted seal such as an O-ring, along with a
flat valve face on the downstream and upstream
sections of the valve.
Used for: In the food & beverage and chemical
processing industries, butterfly valves are used in
almost every application outside of dairy.
Construction: Steel or stainless steel.
DISADVANTAGES
• Requires more service than ball valves.
• Prone to water hammer.
• Not deemed a sanitary valve by the 3-A
and the USDA.
• Can only be cleaned-in-place when the
valve is actuated, and this practice does
not follow 3A guidelines.
• Depending on temperature and
pressure, may not provide a tight
shut-off.
• A portion of the valve is always in the
product flow passage.
ADVANTAGES
• Light weight.
• Relatively low cost.
• If constructed from the proper materials,
can be used with corrosive liquids at low
temperatures and pressures.
• Easy on product.
• Can be configured for manual or
automatic operation.
• May be used to meter the flow of liquid
through the valve.
• Reliable
• Can be used as a throttling valve.
ADVANTAGES & DISADVANTAGES
OF BUTTERFLY VALVES
TYPES OF VALVES
VALVE BUYING GUIDE
8

9. SEAT VALVES
How it works: Also known as rising stem valves, seat
valves use a stopper at the end of an actuating stem
to shut off product flow through the valve’s body.
Used for: Seat valves are the primary hygienic
valve used in processing industries around the
world. These valves are generally well-suited for all
sanitary applications.
Construction: Steel, stainless steel, or alloys.
DISADVANTAGES
• In comparison to other types of valves,
a relatively complex valve, with many
moving parts.
• Maintenance costs are higher than with
other valve types.
ADVANTAGES
• 100% drainable if properly engineered
and installed in a process line.
• Not prone to water hammer if properly
installed.
• May be operated manually or
automatically.
• Reliable
ADVANTAGES & DISADVANTAGES
OF SEAT VALVES

10. MIXPROOF VALVES
How it works: Mixproof valves operate in a similar
manner to two or three single seat valves, and are
used to separate two different and incompatible
liquids, preventing the two materials from
accidentally mixing. The valve itself features two
independently-controlled valve stems, designed for
automated operation, which give it this capability.
Should any leaks occur, the valve is designed so
that the fluids divert to atmosphere, rather than
contaminating the other line.
Used for: Well-suited for CIP applications, where
cleaning fluids can flow through one line while
product is flowing in an adjacent line without the
risk of cross-contamination. Mixproof valves are
generallyexcellentfornearlyallsanitaryapplications.
These are great valves that are commonly used to
connect together process equipment, tanks, and
CIP systems to maximize plant productivity.
Construction: Steel, stainless steel, and alloys.
DISADVANTAGES
• A complex valve in comparison to other
types of valves.
• Relatively expensive.
• Since mixproof valves are always
automated, requires a considerable
investment in controls.
ADVANTAGES
• CIP’able
• Allows for a simplified process flow in
double “block and bleed” applications.
• Saves on space and installation costs.
• Allows for simplified process piping.
• Increased operator control.
• An excellent valve for automating
process operations, and reducing
operator error.
ADVANTAGES & DISADVANTAGES
OF MIXPROOF VALVES
TYPES OF VALVES
Mixproof Valve
with Control Top
VALVE BUYING GUIDE
10

11. AIR BLOW CHECK VALVES
How it works: Air blow check valves are one-way
valves that are used to prevent product from backing
up into an air line. They work automatically, and are
not controlled by a person or an outside controller:
accordingly, most do not have any valve handle
or stem. They allow processing plants to recover
product from lines that would otherwise be lost to
cleaning processes.
Used for: Air blow check valves are commonly used
in the beverage, chemical, and dairy industries to
evacuate process lines of either product or CIP
solutions in-between runs. They accomplish this by
forcing compressed air through the pipes.
Construction: Steel or stainless steel.
DISADVANTAGES
• The filter disks in the air lines are often
not properly maintained, so “dirty” air
can be introduced into the process
piping, causing product contamination.
• Most air blow check valves are not 3-A
approved for CIP, and must be cleaned
by hand. An exception, though is the
TrueClean® CIP’able air blow check valve
offered by CSI.
• Cannot be used with pulsating systems.
• The closing element may crash, causing
damage and excessive wear.
ADVANTAGES
• Relatively simple and reliable.
• Prevents backflow into air push lines.
• Can sustain pressure.
ADVANTAGES & DISADVANTAGES
OF AIR BLOW CHECK VALVES
CIP’able Air Blow
Check Valve
Air Blow Check Valve

12. Valve manifolds are used in some process-focused
industries to connect together two or more valves
in a fluid transfer system. They are typically used to
clean a process line within a plant while operating
other processing equipment in a different area of
the tank farm or packaging line.
As shown in the figure below, valve manifolds
consist of an array of valve bodies which are directly
connected to each other via a manifold. In many
cases, literally dozens of valves can be connected
together in this manner.
AUTOMATION AND CONTROLS
As noted in the introduction to this article, all valves
contain actuators which are used to control the
operation of the valve. The actuator is operated
either manually (i.e., by turning a handle or lever) or
automatically via electrical impulse, pneumatics, or
hydraulics. In most process plants found in both the
pharmaceutical manufacturing and food & beverage
processing industries, the large number of valves in
use in a system dictates that the valves be opened
and closed via automatic means. The most common
types of valves used in automated systems include
butterfly valves, seat valves, and mixproof valves.
Automated valves are typically used in conjunction
with what is called a control top (which is a control
and indications instrument). Control tops are
optional devices that sit on top of an automated
valve actuator, and provide real-time information,
electronically, on the performance of the valve.
A representative control top is shown in the
illustration below:
VALVE MANIFOLDS
All valve manifolds are custom-built to meet a
given customer’s specific process system design,
process application, and type of valve to be used
in the valve manifold. In other words, each valve
manifold has been uniquely engineered to meet a
specific requirement.
As described in the previous section, there are
several types of valves commonly used in a valve
manifold system, including seat valves, mixproof
valves, and butterfly valves.
VALVE BUYING GUIDE
12

13. Control tops tell plant operators if a specific valve
is open, closed, or partially opened in a throttling
position. They provide a systems-level view of the
performance of all of the valves in the processing
plant. Information that is transmitted by control
tops may be looped into a system network,
controlled by a PLC (programmable logic controller),
or monitored remotely from a control room in the
processing plant.
There are a number of distinct advantages that
come with adding control tops to automated
valve actuators. In addition to the real-time
operator feedback on valve performance that was
noted above, valve actuator control tops afford a
considerable cost savings over using automated
valve actuators without them. For example, without
a control top, a PLC may think that a valve is open
when it actually isn’t. Were this to happen, thousands
of dollars worth of product could accidentally be
sent down a waste drain, or contaminate a large
storage silo. Most large process pipeline system
operators, then, will pay for the extra cost to install
control tops on their automated valve actuators as a
risk mitigation measure.
Since control tops are used to transmit real-time
information about the performance of automated
valve actuators in a valve system, they are designed
to be used and controlled via a communications
network in the process plant. Depending on the
specific type of automated valve actuator control
top in use, there are several different types of
communications protocols that may be available.
The default communications network used with
valve actuator control tops is typically a 24 VDC
digital wiring loom. However, more sophisticated
controls may be afforded by the use of industrial
network protocols (i.e., field bus networks) that
can manage real-time operational control and data
integrity in large installations. These are described
briefly in the following paragraphs.
Field bus networks are local area networks (LANs)
that provide a digital, two-way communications
link between a controller and the pipeline system’s
intelligent field devices, including automated valve
actuator control tops. These types of networks
require far less wiring than do traditional 24 VDC
networks, and hence are cheaper to install from a
labor perspective. They can also provide additional
diagnostic capabilities, and a large number of data
I/O (input/output) points on the network.
There are several field bus network technologies
that are commonly used in process automation
applications. Modbus in particular has become the
de facto standard for use in industrial applications,
and supports communications to and from multiple
devices connected to the same cable or Ethernet
network. There is also CAN bus (aka controller area
network), which allows microcontrollers and other
similar devices to communicate with each other’s
applications without the need for a host computer.
SUMMARY
In conclusion, valves are an integral part of plant
operations in all processing industries. With so
many different types of valves to choose from, it’s
particularly important to do your research, and
select the type of valve that’s most suited for your
particular application. Pay close attention to whether
the valve you choose is appropriate for sanitary
processing (if applicable), and whether or not the
valve can be cleaned-in-place. And, decide whether
your application would benefit from a well-designed
valve manifold system and/or the use of control tops
for automated valve actuators.

14. NOTES
VALVE BUYING GUIDE
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15. NOTES

16. VALVE BUYING GUIDE REV 8/20
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