Duo-Check
II - The High Performance Check Valve
The
innovative dual-plate design is generally stronger, lighter and smaller than conventional
flanged Swing Check valves and comes in a wide variety of cast materials for bodies,
plates and for all types of service and temperature conditions.
The
Duo-check II valve has exclusive design and features that result in exceptional
high performance and reliability for most liquids, vapour, gas and fluid applications.
This valve incorporates the sound, imaginative design that has characterized Duo-check
Check valves for many years…. Plus added features that offer performance advantages
not found in any other available check valve.
APPLICATIONS
Suitable for most standard backflow prevention requirements. Provides advantages
lightweight, compactness and ease of installation. Lug style preferred in situations
where bolting needs to be enclosed by valve body. |
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The advanced
technology of the Duo-Check II valve provides the Process Engineer with unique
opportunities to advance the science of fluid mechanics and system design.
Duo-Check
II Check Valves are available to meet your process conditions.
A
complete range of sizes from 40mm (1 ½") through to 2200mm(88").
A wide variety of cast materials for bodies, plates and trim for all types
of service and temperature conditions.
Full
line of Duo-Check II Valves, designed and rated in accordance with ANSI 125# through
2500# and API 2000# through 5000# and 10000# standards.
For
pressures from vacuum through 6,170 psi (425 bars).
For operational
temperatures from-267° C (-450° F) through 538° C (1000°
F) depending on materials of construction.
The
Duo-check II meets API 594 wafers check Standard except face- to-face on ANSI
125 cast iron 65mm (2 ½") through 300mm (12") dimensions.
ADVANTAGES
Lightweight, small size, and strong construction compared with conventional swing
check valves.
Dual - Plate, flat seat design for efficient seating under most flow and pressure
conditions.
Long-leg spring action allows the plates to open and close without seat scrubbing
but designed to respond to flow quickly.
Independent spring design which provides as much as 25 percent lower stress and
50 percent reduction of water hammer.
Independent plate suspension which reduces friction by 66 percent, which minimizes
water hammer
Lower head loss than Swing Check Valves in larger sizes
Duo-Check
II high performance check valves are available in the sizes, pressures classes
and configurations you need to meet the most demanding of applications. Our products
range includes the following:
ANSI Class 125 through 2500
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Body
Material
Cast iron, Ductile iron, WCB cast Steel, 316 Stainless steel, All alloys |
| API 6A and ^D pressure classes also available |
Resilient seal materials
- EPDM, Buna - N- Neoprenne, Refrigeration - grade elastomer,
Viton - B |
| Sizes from 1-1/2 through 72 inches |
Metal seals also available |
| Lug,
wafer, double flanged and extended body styles |
End
Connections - Raised face, Plain face, Ring joint, Weld - end, Hub - end |
| All body configurations available in retainer less style. |
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INDUSTRY
STANDARDS |
| API
594 |
Valve
Design |
| API
598 |
Valve
Pressure testing and Inspection |
| ASME/ANSI
B16.34 |
Pressure
/ temperature Ratings |
API
6D |
Pipeline
Valves |
| API
6A |
Production
Valves |
SPECIFY
THE DUO-CHEK II … TO your advantag
The
innovative dual-plate design of the Du- Chek II employs two spring - loaded plates
( disc halves) suspended on a central vertical hinge pin. As flow begins, the
plates open in response to a resultant force (F) which acts at the center of the
sealed surface area. The contract point of the reacting spring leg's force ( Fs)
acts beyond the center of the plate area, causing the heel to open first. This
prevents rubbing of the seal surface prior to normal plate opening.
As
the velocity of flow decreases, torsion spring action reacts automatically. This
moves the plate closer to the body seats, reducing the distance and time of travel
for closure. By having the plates closer to the bosy seats at the time of flow
reversal, the valve dynamic response is greatly enhanced. This is dramatically
reduces the water hammer effect.
At
closing, the point of spring forces causes the toe of the plates to close first.
This prevents draging of the heels of the plates and maintains seal integrity
for much longer periods.
Independent
Spring Design
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Spring
design of the Duo-Chek II (sizes 6" and larger) allows higher torque to be
exerted against each plate with independent closing in response to the process
stream. Testing has proved this action provides up to 25% improvement in value
life and 50% reduction in water hammer.
Each
of the dual plates has its own spring or springs, which provide independent closing
action. These independent springs undergo less angular deflection, only 140 as
compared to 350 from conventional springs with two legs.
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Independent
Plate Suspension Design
The Duo-Chek
II hinge design reduces friction forces by 66% which improves valve
response significantly. Support sleeves are inserted through the outboard
hinges so that the upper hinge is independently supported by the lower
sleeves during valve operation. This allows both plates to close at
same time quick response.
Compac
- Noz Non-Slam Check Valves |
| Scope
of Line and Features |
Sizes 12"-60"
ASME B16.34 & API Pressure classes 150-4500
API 6A pressure classes 2000-15000
API 594 end to end dimensions
Flanged, Butt-weld ends, hub ends and specials
Wide
range of materials of construction Available-
consult factory for special
application requirements
Valve is offered in a wafer design. Consult factory |
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High
Performance
Non-Slam Nozzle Check Valve
The
most important aspect of a check valve in a piping system is to
protect equipment and prevent damages caused by backflow. Engineers
today are very aware of the valve characteristics they need for
their particular system installations. They require valves to
close quickly and prevent flow reversal that can damage mechanical
equipment and cause destructive events such as water hammer. Space
and weight restrictions are very often also a significant concern.
The Compac-Noz™ valve provides the industry with a short
face to face, light weight, quick closing non-slam nozzle check
valve.
Features and Benefits |
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Compact
design and short face to face to meet API 594
One
moving part resulting in minimal wear and long service life
Quick
dynamic response reducing reverse velocity and minimizing damaging water hammer
Short
stroke to help in quick response
Low
pressure loss
Choice
of springs for specific critical velocity and valve response
Suitable
for reciprocating compressor service eliminating chatter
Spring
is internal and protected from process flow
Preferred
in centrifugal compressor service
The
valve compact face to face and rigid design means it is easy to install and needs
no special supports. Its lightweight when compared to traditional nozzle type
check valves can also mean reduced cost of installation for the customer. The
dynamic response of the valve has been verified by an independent testing institution.
The Compac-Noz valve represents the latest innovative addition to our extensive
line of check valves. Crane has over thirty years of experience in the design
manufacture and application of check valves.
CRANE Compac-Noz™
is designed and manufactured to the highest quality standard including API 6D,
ISO-9001, Stoomwezen and TUV.
INDUSTRY
STANDARDS |
| API 594 |
End-to-End Dimensions |
| API 598 |
Pressure Testing & inspection |
| ASME B 16.34 |
Pressure / Temperature Ratings |
| API 6D |
Pipeline Valves |
| API 6A |
Production
Valves |
Technical
Information & Apllications |
APPLICATION
Gas Transmission
Compressor
Discharge
Power Generation
Feedwater
Cooling
water
Blowdown
Steam
Petro-Chemical/ Chemical Processing
Extreme
Units
Propylene
Units
Hydrocarbon Processing
Catalytic
Cracking
Hydrotreating
Water Transmission
Pipeline
Pump
Compressor Station
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Testing
Each valve is hydristatically testeesto API 598. Cryogenic and fire
test can be conducted to satisfy custemer requirements.Other testing capabilities
include radiography, magnetic particle and liquid penetrant
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ADVANTAGES
Compac-Naz™ Valves have the following advantages when
compared to other nozzle valves:
Ease of installation
API
594 Face to Face
Compact
and lower weight
Lower
pressure drop compared with similar valves
Dynamic
performance matches standard nozzle type valves
Ease
of maintaince with longer valve life
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Only one seating surface with zero or low leakage rate
Large flow passages resulting in less flow erosion due to lower velocities
CHARACTERISTICS
Compac-Noz valves deliver an effective dynamic response under various
flow deceleration conditions. The dynamic performance characteristics of the Compac-Noz
valves are compared to swing check and dual plate spring-assisted check valves
Noz
- Check
Valves - High Performance
|
The
Noz- Check is a high performance non-return check valve offering four major benefits
for critical service applications.
Minimises
water hammer in liquid service
Removal of chatter associated with conventional valves in reciprocating compressor
service
Protects
rotating equipment from damage due to flow reversal
Minimises
the pressure loss in the piping
It
optimizes the performance between low-pressure loss and quick dynamic response
keeping the reverse velocity to a minimum.
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The Noz-Check is produced in three body styles. Selection is based on ANSI
pressure class and nominal size, and is made to provide the highest quality cast
product at the most cost -effective price.
Style
NC Standard Pattern face to face dimensions comply with ASME B16.10.
Style
NCS Short Pattern is offered where weight and space limitations exist.
Style
NC and NCS both have excellent dynamic performance characteristics and optimized
streamline flow path to minimize pressure loss.
Style
WN Wafer Pattern face-to-face dimensions comply with API 594. with exceptional
dynamic response and very shirt face-to-face dimensions, Style WN is particularly
suited to installations with critical space and weight limitations.
SEAT
SEALING
Metal -to-metal or bubble tight resilient seats.
BODY
& TRIM MATERIALS
Most castable materials including Ductile Iron, Carbon
Steel, Alloy Steel, Stainless Steel and Duplex Steels.
PRESSURE
CLASSES
ANSI 150 to 2500
API 2000 to 10,000
END
CONNECTIONS
Flanged to meet all International Standards
Butt Weld
Ends
Clamp Type Hub Ends
Special Seal Designs
TEMPERATURE
RANGE
-196°C (-300°F) to 537°C (1000°F)
Size
2 - 60"
ASME B16.34 & API 6D, pressure classes 150-4500
API 6A pressure classes 2000-15000
Flanged, butt-weld ends, hubs ends and specials
Standard and shor Pattern
Wide range of materials of constructions avilable - consult factory for special
application requirements
Noz- Check High Performance
Non Slam Check Valve
One of the most significant elements of piping system design is integrating the
means to protect mechanical equipment and prevent damage caused by back flow.
Backflow preventions is routinely achieved through the use of swing check valves
or dual - plate check valves.
Noz - Check valves are specifically designed
for fastreversing system where backflow is a constant concern. In such critical
services applications, Non - check Non Slam check valves offer the
following benefits.
Minimizes the damaging effects of water hammer in fluid systems
Removal
of chatter associated with conventional valves in reciprocating compressor service,
Protects rotating equipment from damage due to flow reversal.
Minimizes
pressure loss in piping system.
Provides
quick dynamic response reducing reverse velocity
Minimizes pressure loss in piping systems
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Non- Check
is designed and manufactured to the highest quality standards including ISO-9001,
Stoomwezen and TUV
INDUSTRY
STANDARDS |
| API
598 |
Valves
Pressure Testing & Inspection |
| ASME
B16.34 |
Pressure/Temperature
Rating |
| API
6D |
Pipeline
Valves |
| API
6A |
Production
Valves |
Features
& Characteristics |
FEATURE
Extensive research and development coupled with valid design procedures,
have resulted in these unique Noz Chek feature
FEW MOVING PART
Disc is the only moving part, minimizing wear.
AXIAL MOVEMENT OF DISC
Disc and seating configuration give streamlined
flow path with venturi effect, resulting in low pressure drop.
SHORT STROKE OF SPRING ASSISTED DISC
Inlet flow velocity moves disc axially
with short stroke. In response to flow velocity reduction, a compressed spring
initiates valve closure and provides quick response
SPRING OPTIONS
Choice of spring affects critical velocity and valve response.
Selection is made on engineering evaluation of specific applications. In absence
of this data, a standard spring will be provided.
CHARACTERISTICS
Noz-Chek valves deliver an effective dynamic response under various
flow deceleration conditions. The dynamic performance characteristics of Noz-chek
valves are compared to swing check and dual plate spring-assisted check valves
in fig. 1
Noz Chek unique design features result in superior performance,
fast response and lower pressure loss in piping system.
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TOTAL QUALITY MANAGEMENT
Crane is guided by a commitment to total quality
mamagement with a focus in customer satisficaton. Design manufacturing and testing
procedures are certified to ISO 9001,EN 29001 & API Q1 and 6D and ASME/ASQC
Q91 Quality Assurance. This quality management system is also approved by stoomwezen
& TUV.
DESIGN
Computer-aided design ( CAD ) systems at Crane are helpful in developing sound
designs. Finite element analysis is utilized to conduct simulated stress analyses
for various valve structures to prove design integrity. Flow modeling is applied
to optimize pressure drop characteristics. Computer generated spring designs and
disc weight studies have improved the Noz-Chek valve response times.
Manufacturing
Capabilities
Non-Check valves can be furnished in sizes from 2" (50
mm) to 60" (1500mm), and in pressure classes from ASME Class 150 through
4500 and API ratings from 2000 to 15000 psi CWP.
A
variety of body and trim material is offered, including carbon steel, ductile
iron, alloy steels, stainless steel and duplex steel. Coatings may be provided
for added corrosion or wear resistance. Hard - facing and weld overlays may also
be supplied. Seats may be metal to metal or bubble tight resilient.
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Inspection and testing are applied throughout the manufacturing process .
Special
nondestructive testing is often specified, which may include radiography, magnetic
particle and liquid penetrant.
Cryogenic
and fire tests can be conducted to satisfy customer requirements.
Each
valve is hydrostatically tested to API Standard 598. These tests
apply to the body shell and seat, with test duration and leakage
rates pertaining to customer requirements. Other test standards
are also specified in some cases.
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