TRIPLE OFFSETBUTTERFLY VALVETYPE LTR 43

SMART IN FLOW CONTROLFEATURES AND BENEFITS

Excellent Controllability

Retained Shaft

Specially machined andpolished shaft reduces
friction, hysteresis, andtorque requirement.

An external shaft retainer
located outside of theprocess medium increases
product safety by preventing
shaft blow-out.

Replaceable Body Seat(yellow)

In addition to the disc seal,
the body seat can be easily
replaced in the field. Many
competing triple offset
butterfly valve designs utilize
an integrated seat, requiring
repairs to be done in aspecialty machine shop.

Cryogenic & High
Temperature

The laminated seat
design provides for slightflexibility, this maintains
a tight shut-off even in
extremely low or hightemperatures.

Replaceable Disc Seal ring
Large Sealing Surface Area

The large sealing surfaceof the seat and disc seal
ring guarantee bi-directionaltight shutoff, even athigh pressures.

Secured Fasteners

Internal fasteners are secured
with special washers. Ensuringthat the sealing system is
not compromised while
maintaining a user friendlyand serviceable design.

Like the body seat, thedisc seal ring is also field
replaceable. This allows
for a dependable tight seal
and a longer service life.

Large Shaft and Shaft
Bearings

A large shaft andreplaceable shaft bearings
provide long term
reliability and reduced
torque requirements.

OTHER BENEFITS
VA standard design with high quality materials, suitable for fire-safe applications at no extra cost.

VThe standard LTR 43 valve can be used for up to Safety Integrity Level III applications acc. to IEC 61508.

VA valve designed and built for maximum service life, providing for a low total cost of ownership.

Triple Offset Butterfly ValveEVOLUTION
BUTTERFLY VALVE
1 CENTRIC
The first butterfly valve was designed

OFFSET BUTTERFLY VALVE (TOBV)
3 TRIPLE
A further improvement on the DOBV design, the TOBVin such a way that the body, shaft,and seat all shared the same axis. The
disadvantage of this early design is thatit creates significant friction between
the disc and seat during the opening
and closing operation.

adds a third offset in which the geometrical design ofthe seating system forms a conical shape with respect
to the centerline of the body (3rd offset). This allows thedisc to immediately lift off the seat and eliminates any
friction at small opening angles. This also allows for alarger sealing surface, providing better overall shut-off.

OFFSET BUTTERFLY VALVE (DOBV)
2 DOUBLE
To eliminate the main disadvantages of thecentric butterfly valve design, the DOBV design
was developed. The rotational axis of thedisc was set behind the centerline of the bodyseat (1st offset) and also slightly offset fromthe centerline of the valve body (2nd offset),eliminating any contact between the disc andbody (and therefore friction) while thevalve is operating. However, significant
friction still exists when the valve iswithin the first few degrees ofopening/closing.

DESIGN BENEFITS OF A TRIPLE OFFSET BUTTERFLY VALVE
V

Reduced wear and tear

VLower actuator torque requirement

VTight shut-off achievable over a longer service life

SPECIAL APPLICATIONS
Cavitation, Flashing and High NoiseSpecial Trim Modification for Start-up
and Minimum Flow Service

CHALLENGES
VCavitation bubbles form during throttling inthe vena contracta and subsequently implode.

VHigh velocity of liquid droplets during flashingand partial flashing.

VNoise emissions generated through highpressure drops in gases, and cavitationin liquids.

V

Cavitation, flashing, and excessive noise cancause damaging vibration of the valve, pipeline,
and other components in the system.

CHALLENGES
The optimal control range for butterfly valves is
between 8° and 64°. Significant challenges arise
during plant startup and commissioning whereopening angles can be as low as 2°.

SOLUTIONSThe specially designed anti-cavitation trim plate
ensures that the pressure in the vena contracta
does not fall below the vapor pressure. The
flexibility of this trim design combats challenging
process conditions, and up to a 10 dB(A) noise
reduction can also be achieved.

SOLUTIONS
A specially designed trim alters the characteristicof the disc in the lower operating angles without
affecting the overall flow capacity of the valve.
This eliminates the need for smaller start-up or
bypass valves.

SPECIAL APPLICATIONSCryogenic Applications

Solid Particles in Liquids & Gases
CHALLENGES
Particles entrained in the operating medium canfind their way into the shaft bearing, potentiallycausing difficulty in control or damage tointernal valve components.
SOLUTIONSVAn optional metallic bearing protector ringwelded on the inside of the valve prevents
particles from entering the bearing area.

VThe LTR 43 inner packing/outer bearing
design utilizes the soft packing to block theingress of particles, thereby protecting theshaft and bearing from damage. This provensolution is also used for aggressive media
where bearing materials can be limited.

Other Special Options
VNACE Version according to ISO 15156 /MR0103 / MR0175

VNoise and cavitation reducing discs

VVersion for high cycle counts

VEmergency shutdown & blowdown valves
with fast stroking speeds (<0.3s)

CHALLENGES

VInternal valve leakage and sticking problems
caused by material contraction from extremely
low temperatures.

Heating jacket to maintain ideal process fluidtemperatures

VTop Entry design for LNG and otherspecial applications

VStreamlined disc design for reduced pressure
loss under maximum flow conditions

VDouble packing with drainage line

VLive loading packing for emissions reduction

VLow emission packing acc. to ISO 15848-1
and TA-LuftVElectric and pneumatic actuators (ScotchYoke, Rack and Pinion, Diaphragm type)

SOLUTIONSThe use of high quality materials and precision
machining allows for the strict tolerances
required in cryogenic applications; operating
conditions down to -320°F (-196°C) can be achieved.
SAMSON Leusch LTR 43-2 & LTR 43-4 valves
have been successfully tested under cryogenic
conditions in sizes up to 36” and ANSI Class 600(acc. to BS 6364).

TECHNICAL DETAILS
Valve Size

NPS 3” to 100”

Pressure Rating

ANSI Class 150 to 2500

End ConnectionsVLuggedV

Flanged

VWaferV

Standard Butt-weld and Top Entry Butt-weld

V

Carbon Steel (A216 WCC)V

Stainless Steel (A351 CF8M)

V

Low/High Temperature Steels (LCC/LC3/WC6/WC9)V

Special Alloys (Duplex, Monel, Titanium, etc.)

Materials

Temperature Range-320 to 1832°F (-196 to 1000°C)

Internal Leakage RateClass VI according to ANSI/FCI 70-2 , API 598 & IEC
60534-4

Fire Safe

According to API 607, API 6FA, and BS 6755 Part 2

GENERAL INDUSTRIESAPPLICATIONS

Chemical/Petrochemical, Oil & Gas (upstream,midstream, & downstream), Refining, Powergeneration, Industrial gases, Steel production,Desalination plants, Renewable energy (solar,geothermal, and hydro), Shipyard, Aerospace,Cryogenic, etc.

Gas: Natural gas, Syngas, Oxygen, Hydrogen,Nitrogen, Air, Carbon dioxide, Flue gas, Cokeoven gas, Flare gas, Sour gas, Acidic gas, Steam(saturated and superheated), Ethylene, Methane,Ammonia, etc.

SAMSON Controls Inc.
4111 Cedar Blvd. Baytown, TX 77523-8588 USA
Phone: +1 281-383-3677 · Fax: 281-383-3690
www.samsoncontrols.com

contact-us@samsongroup.com

2019-07 | NA 101

Liquid: Hydrocarbon (diesel, crude oil, naphtha,
jet fuel, kerosene, gasoline etc.), Sea water, Wastewater, Heat transfer fluid, Thermal oil, Molten
salt, etc.