Samson 3251 Service manual

Translation of original instructions
EB 8052-1 EN
Edition July 2020
Type3251 Valve for molten salt service · ANSI version
In combination with an actuator,
e.g. a Type3271 or Type3277 Pneumatic Actuator

Note on these mounting and operating instructions
These mounting and operating instructions assist you in mounting and operating the device
safely. The instructions are binding for handling SAMSON devices. The images shown in
these instructions are for illustration purposes only. The actual product may vary.
ÎFor the safe and proper use of these instructions, read them carefully and keep them for
later reference.
ÎIf you have any questions about these instructions, contact SAMSON‘s After-sales Service
([e-mail]).
Documents relating to the device, such as the mounting and operating
instructions, are available on our website at www.samsongroup.com >
Service & Support > Downloads > Documentation.
Definition of signal words
Hazardous situations which, if not avoided,
will result in death or serious injury
Hazardous situations which, if not avoided,
could result in death or serious injury
Property damage message or malfunction
Additional information
Recommended action
DANGER
!
WARNING
!
NOTICE
!
Note
Tip
EB 8052-1 EN

Contents
EB 8052-1 EN
1 Safety instructions and measures ................................................................1-1
1.1 Notes on possible severe personal injury ......................................................1-4
1.2 Notes on possible personal injury ................................................................1-5
1.3 Notes on possible property damage.............................................................1-7
1.4 Warnings on the device...............................................................................1-8
2 Markings on the device ..............................................................................2-1
2.1 Valve nameplate .........................................................................................2-1
2.2 Actuator nameplate.....................................................................................2-2
2.3 Material numbers........................................................................................2-2
2.4 Label when an adjustable packing is installed ...............................................2-2
3 Design and principle of operation ...............................................................3-1
3.1 Versions .....................................................................................................3-4
3.2 Additional ttings........................................................................................3-4
3.3 Valve accessories........................................................................................3-5
3.4 Technical data ............................................................................................3-5
4 Shipment and on-site transport ...................................................................4-1
4.1 Accepting the delivered goods .....................................................................4-1
4.2 Removing the packaging from the valve........................................................4-1
4.3 Transporting and lifting the valve..................................................................4-1
4.3.1 Transporting the valve .................................................................................4-2
4.3.2 Lifting the valve...........................................................................................4-3
4.4 Storing the valve.........................................................................................4-4
5 Installation.................................................................................................5-1
5.1 Installation conditions..................................................................................5-1
5.2 Preparation for installation...........................................................................5-3
5.3 Assembly ...................................................................................................5-3
5.3.1 Mounting the external anti-rotation xture.....................................................5-4
5.3.2 Mounting the actuator onto the valve..........................................................5-12
5.3.3 Installing the valve into the pipeline ............................................................5-13
5.4 Conguring the temperature control............................................................5-14
5.4.1 Determining the temperature limits .............................................................5-15
5.4.2 Calculating the required heating power ......................................................5-15
5.4.3 Conguring the temperature sensor ............................................................5-15
5.4.4 Conguring the electric trace heating..........................................................5-15
5.5 Testing the installed valve...........................................................................5-15
5.5.1 Leak test...................................................................................................5-17
5.5.2 Travel motion............................................................................................5-17

Contents
EB 8052-1 EN
5.5.3 Fail-safe position.......................................................................................5-18
5.5.4 Pressure test..............................................................................................5-18
6 Start-up .....................................................................................................6-1
7 Operation..................................................................................................7-1
7.1 Normal operation .......................................................................................7-2
7.2 Manual operation .......................................................................................7-2
8 Malfunctions ..............................................................................................8-1
8.1 Troubleshooting ..........................................................................................8-1
8.2 Emergency action .......................................................................................8-2
9 Servicing....................................................................................................9-1
9.1 Periodic testing ...........................................................................................9-3
9.2 Preparing the valve for service work .............................................................9-7
9.3 Mounting the valve after service work...........................................................9-7
9.4 Service work...............................................................................................9-8
9.4.1 Replacing the gasket ...................................................................................9-8
9.4.2 Replacing the packing.................................................................................9-9
9.4.3 Replacing the seat and plug.......................................................................9-10
9.5 Cleaning the pipelines...............................................................................9-11
9.6 Ordering spare parts and operating supplies ..............................................9-12
10 Decommissioning .....................................................................................10-1
11 Removal ..................................................................................................11-1
11.1 Removing the valve from the pipeline..........................................................11-2
11.2 Removing the actuator from the valve .........................................................11-2
12 Repairs ....................................................................................................12-1
12.1 Returning devices to SAMSON ..................................................................12-1
13 Disposal...................................................................................................13-1
14 Certicates...............................................................................................14-1
15 Annex......................................................................................................15-1
15.1 Tightening torques, lubricants and tools ......................................................15-1
15.2 Spare parts ..............................................................................................15-1
15.3 After-sales service.....................................................................................15-3

EB 8052-1 EN 1-1
Safety instructions and measures
1 Safety instructions and measures
Intended use
The SAMSON Type3251 Globe Valve in combination with an actuator (e.g. Type3271 or
Type3277 Pneumatic Actuator) is designed to regulate the ow rate of molten salt. The valve
with its actuator is designed to operate under exactly dened conditions (e.g. operating
pressure, process medium, temperature). Therefore, operators must ensure that the control
valve is only used in operating conditions that meet the specications used for sizing the
valve at the ordering stage. In case operators intend to use the control valve in other
applications or conditions than specied, contact SAMSON.
SAMSON does not assume any liability for damage resulting from the failure to use the
device for its intended purpose or for damage caused by external forces or any other
external factors.
ÎRefer to the technical data and nameplate for limits and elds of application as well as
possible uses.
Reasonably foreseeable misuse
The control valve is not suitable for the following applications:
−Use outside the limits dened during sizing and by the technical data
−Use outside the limits dened by the valve accessories connected to the valve
Furthermore, the following activities do not comply with the intended use:
−Use of non-original spare parts
−Performing service and repair work not described
Qualications of operating personnel
The control valve must be mounted, started up, serviced and repaired by fully trained and
qualied personnel only; the accepted industry codes and practices must be observed.
According to these mounting and operating instructions, trained personnel refers to
individuals who are able to judge the work they are assigned to and recognize possible
hazards due to their specialized training, their knowledge and experience as well as their
knowledge of the applicable standards.
Explosion-protected versions of this device must be operated only by personnel who has un-
dergone special training or instructions or who is authorized to work on explosion-protected
devices in hazardous areas.

1-2 EB 8052-1 EN
Safety instructions and measures
Personal protective equipment
We recommend checking the hazards posed by the process medium being used (e.g.
uGESTIS (CLP) hazardous substances database). Depending on the process medium and/
or the activity, the protective equipment required includes:
−Protective clothing, gloves, eye protection and respiratory protection in applications with
hot, cold and/or corrosive media
−Wear hearing protection when working near the valve
−Hard hat
−Safety harness when working at height
−Safety footwear, ESD (electrostatic discharge) footwear, if necessary
ÎCheck with the plant operator for details on further protective equipment.
Revisions and other modications
Revisions, conversions or other modications of the product are not authorized by SAMSON.
They are performed at the user's own risk and may lead to safety hazards, for example. Fur-
thermore, the product may no longer meet the requirements for its intended use.
Safety features
The fail-safe position of the control valve upon air supply or control signal failure depends on
the actuator used (see associated actuator documentation). When the valve is combined with
a SAMSON Type3271 or Type3277 Pneumatic Actuator, the valve moves to a certain fail-
safe position (see the 'Design and principle of operation' section) upon supply air or control
signal failure. The fail-safe action of the actuator is the same as its direction of action and is
specied on the nameplate of SAMSON actuators.
Warning against residual hazards
To avoid personal injury or property damage, plant operators and operating personnel must
prevent hazards that could be caused in the control valve by the process medium, the operat-
ing pressure, the signal pressure or by moving parts by taking appropriate precautions. Plant
operators and operating personnel must observe all hazard statements, warning and caution
notes in these mounting and operating instructions.
Hazards resulting from the special working conditions at the installation site of the valve must
be identied in a risk assessment and prevented through the corresponding safety instruc-
tions drawn up by the operator.

EB 8052-1 EN 1-3
Safety instructions and measures
Responsibilities of the operator
Operators are responsible for proper use and compliance with the safety regulations.
Operators are obliged to provide these mounting and operating instructions as well as the
referenced documents to the operating personnel and to instruct them in proper operation.
Furthermore, operators must ensure that operating personnel or third parties are not exposed
to any danger.
Operators are additionally responsible for ensuring that the limits for the product dened in
the technical data are observed. This also applies to the start-up and shutdown procedures.
Start-up and shutdown procedures fall within the scope of the operator's duties and, as such,
are not part of these mounting and operating instructions. SAMSON is unable to make any
statements about these procedures since the operative details (e.g. differential pressures and
temperatures) vary in each individual case and are only known to the operator.
Responsibilities of operating personnel
Operating personnel must read and understand these mounting and operating instructions as
well as the referenced documents and observe the specied hazard statements, warnings
and caution notes. Furthermore, operating personnel must be familiar with the applicable
health, safety and accident prevention regulations and comply with them.
Referenced standards and regulations
The control valves comply with the requirements of the European Pressure Equipment Direc-
tive 2014/68/EU and the Machinery Directive 2006/42/EC. Valves with a CE marking
have a declaration of conformity which includes information about the applied conformity
assessment procedure. The 'Certicates' section contains this declaration of conformity.
According to the ignition risk assessment performed in accordance with EN13463-1:2009,
section 5.2, the non-electrical control valves do not have their own potential ignition source
even in the rare incident of an operating fault. As a result, they do not fall within the scope of
Directive 2014/34/EU.
ÎFor connection to the equipotential bonding system, observe the requirements specied in
section6.4 of EN60079-14 (VDE0165-1).

1-4 EB 8052-1 EN
Safety instructions and measures
Referenced documentation
The following documents apply in addition to these mounting and operating instructions:
−Mounting and operating instructions for the mounted actuator, e.g. uEB8310-X for
Type3271 or Type3277 Pneumatic Actuator
−Mounting and operating instructions for mounted valve accessories (temperature sensor,
positioner, solenoid valve etc.)
−Documentation for devices by other manufacturers (e.g. for electric trace heating)
−uAB0100 for tools, tightening torques and lubricant
−Manual uH02: Appropriate Machinery Components for SAMSON Pneumatic Control
Valves with a Declaration of Conformity of Final Machinery
1.1 Notes on possible severe personal injury
DANGER
!
Risk of bursting in pressure equipment.
Valves and pipelines are pressure equipment. Impermissible pressure or improper
opening can lead to valve components bursting.
ÎObserve the maximum permissible pressure for valve and plant.
ÎBefore starting any work on the control valve, depressurize all plant sections affect-
ed as well as the valve.
ÎDrain the process medium from all the plant sections concerned as well as the
valve.
Risk of burn injuries due to hot components and pipelines.
Components and pipelines reach temperatures above 300°C (570°F) while the plant is
running. Risk of severe burn injuries if touched.
ÎPrior to performing any work on the valve, allow components and pipelines to cool
down.
ÎWear protective clothing and safety gloves.

EB 8052-1 EN 1-5
Safety instructions and measures
Risk of burn injuries from molten salt.
Molten salt reaches very high temperatures of over 200°C (392°F) and leads to severe
burn injuries if touched.
ÎDo not touch molten salt.
ÎWear protective clothing and safety gloves when handling molten salt.
Risk of fatal injury due to electric shock.
The following applies when using electric trace heating or other electric components to
heat the valve components:
ÎOnly allow properly trained and instructed operating personnel to perform work on
the mounted device.
ÎObserve the safety instructions in the associated documentation.
1.2 Notes on possible personal injury
WARNING
!
Fire risk due to molten salt.
Individual elements in molten salt (both in crystallized and liqueed state) can acceler-
ate combustion or ignite on coming into contact with certain substances (e.g. graphite).
ÎDo not allow molten salt to come into contact with ammable substances.
Risk of poisoning from molten salt vapors.
Molten salt in the liqueed state produces vapors that are toxic.
ÎDo not inhale molten salt vapors.
ÎMake sure the area is sufciently ventilated.
ÎWear a respirator.
Risk of hearing loss or deafness due to loud noise.
The noise emissions depend on the valve version, plant facilities and process medium.
ÎWear hearing protection when working near the valve.

1-6 EB 8052-1 EN
Safety instructions and measures
WARNING
!
Risk of personal injury due to exhaust air being vented.
While the valve is operating, air is vented from the actuator, for example, during
closed-loop operation or when the valve opens or closes.
ÎInstall the control valve in such a way that vent holes are not located at eye level and
the actuator does not vent at eye level in the work position.
ÎUse suitable silencers and vent plugs.
ÎWear eye protection when working in close proximity to the control valve.
Crush hazard arising from moving parts.
The control valve contains moving parts (actuator and plug stem), which can injure
hands or ngers if inserted into the valve.
ÎDo not insert hands or nger into the yoke while the air supply is connected to the
actuator.
ÎBefore working on the control valve, disconnect and lock the pneumatic air supply
as well as the control signal.
ÎDo not impede the movement of the actuator and plug stem by inserting objects into
the yoke.
ÎBefore unblocking the actuator and plug stem after they have become blocked (e.g.
due to seizing up after remaining in the same position for a long time), release any
stored energy in the actuator (e.g. spring compression). See associated actuator
documentation.
Risk of personal injury due to preloaded springs.
Valves in combination with pneumatic actuators with preloaded springs are under ten-
sion. These control valves with SAMSON pneumatic actuators can be identied by the
long bolts protruding from the bottom of the actuator.
ÎBefore starting any work on the actuator, relieve the compression from the preload-
ed springs (see associated actuator documentation).

EB 8052-1 EN 1-7
Safety instructions and measures
WARNING
!
Risk of personal injury due to residual process medium in the valve.
While working on the valve, residual medium can ow out of the valve and, depending
on its properties, cause personal injury, e.g. (chemical) burns.
ÎIf possible, drain the process medium from all the plant sections affected and the
valve.
ÎWear protective clothing, safety gloves, respiratory protection and eye protection.
Risk of personal injury through incorrect operation, use or installation as a result of
information on the valve being illegible.
Over time, markings, labels and nameplates on the valve may become covered with dirt
or become illegible in some other way. As a result, hazards may go unnoticed and the
necessary instructions not followed. There is a risk of personal injury.
ÎKeep all relevant markings and inscriptions on the device in a constantly legible
state.
ÎImmediately renew damaged, missing or incorrect nameplates or labels.
1.3 Notes on possible property damage
NOTICE
!
Risk of valve damage due to contamination (e.g. solid particles) in the pipeline.
The plant operator is responsible for cleaning the pipelines in the plant.
ÎFlush the pipelines before start-up.
Risk of damage to the valve and pipelines due to the process medium crystallizing.
The molten salt crystallizes when its temperature falls below the salt's melting point. The
crystallized medium accumulates in the valve and pipelines causing them to become
blocked. The bellows seal is damaged as a result.
ÎObserve the temperature limits of the process medium. See 'Conguring the tem-
perature control' in the 'Installation' section.

1-8 EB 8052-1 EN
Safety instructions and measures
NOTICE
!
Risk of leakage and valve damage due to excessively high or low tightening
torques.
Observe the specied torques when tightening control valve components. Excessive
tightening torques lead to parts wearing out more quickly. Parts that are too loose may
cause leakage.
ÎObserve the specied tightening torques (uAB0100).
Risk of valve damage due to the use of unsuitable tools.
Certain tools are required to work on the valve.
ÎOnly use tools approved by SAMSON (uAB0100).
Risk of valve damage due to the use of unsuitable lubricants.
The lubricants to be used depend on the valve material. Unsuitable lubricants may cor-
rode and damage surfaces.
ÎOnly use lubricants approved by SAMSON (uAB0100).
Risk of the process medium being contaminated through the use of unsuitable lubri-
cants and/or contaminated tools and components.
ÎKeep the valve and the tools used free from solvents and grease.
ÎMake sure that only suitable lubricants are used.
1.4 Warnings on the device
Warning Meaning of the warning Location on the device
Warning against moving parts
There is a risk of injury to hands or ngers through the
stroking movement of the actuator and plug stem if they
are inserted into the yoke while the air supply is con-
nected to the actuator.

EB 8052-1 EN 2-1
Markings on the device
2 Markings on the device
2.1 Valve nameplate
22
21
20 19
1817
16
151413121110
8
7
6
5
4
2
1
Fig.2-1: Inscriptions on the valve nameplate
Fig.2-1 and the inscription table list all
possible characteristics and options that may
appear on a valve nameplate. Only the
inscriptions relevant to the ordered
Type3251 Valve for molten salt applications
actually appear on the nameplate.
Note
Item Inscription meaning
1 Data Matrix code
2 Type designation
4 Material
5 Month and year of manufacture
6Valve size:
DIN: DN · ANSI: NPS · JIS: DN
7 Pressure rating:
DIN: PN · ANSI: CL · JIS: K
8 Order number/item
10 Flow coefcient:
DIN: KVS · ANSI: CV
11 Characteristic:
%: equal percentage · LIN: linear
mod-lin: modied linear
NO/NC: on/off service
12 Seat-plug seal:
ME: metal · HA: carbide metal ·
ST: metal base material with Stellite®facing
KE: ceramic · PT: PTFE soft seal · PK: PEEK
soft seal
13 Seat code (trim material): on request
14 Pressure balancing:
DIN: D · ANSI/JIS: B
Version:
M: mixing valve · V: ow-diverting valve
Item Inscription meaning
15 Noise reduction:
1:ow divider(ST)1 · 2:ST2 · 3:ST3
1/PSA:ST1 standard and integrated in
seat for PSA valve
AC-1/AC-2/AC-3/AC-5:AC trim, versions
1 to 5 ·
LK: perforated plug · LK1/LK2/
LK3:perforated plug with ow divider ST1
to ST3 · MHC1:multi-hole cage
CC1:Combi Cage · ZT1:Zero Travel
16 Country of origin
17 PSA version:
PSA
18 Cage/seat style:
CC: clamped cage, clamped seat
SF: suspended cage, anged seat
19 CE marking
20 ID of the notied body
PED: Pressure Equipment Directive
G1/G2: gases and vapors
Fluid group1= hazardous
Fluid group2= other
L1: liquids
Fluid group1= hazardous
Fluid group2= other
I/II/III: Category 1 to 3
21 Serial number
22 NE53 (NAMUR Recommendation)

2-2 EB 8052-1 EN
Markings on the device
The nameplate (80) is afxed to the yoke of
the valve (see Fig.2-2).
80
80
Fig.2-2: Nameplate position
2.2 Actuator nameplate
See associated actuator documentation.
2.3 Material numbers
The seat and plug of the valves have an item
number written on them. You can contact us
stating this item number to nd out which
material is used. Additionally, a seat code is
used to identify the trim material. This seat
code is specied on the nameplate.
2.4 Label when an adjustable
packing is installed
An instructional label is afxed to the valve
when an adjustable packing is installed (see
Fig.2-3).
Fig.2-3: Label when an adjustable packing is
installed

EB 8052-1 EN 3-1
Design and principle of operation
3 Design and principle of oper-
ation
See Fig.3-1 on page3-3.
The Type3251 Valve is a single-seated
globe valve. This valve is preferably com-
bined with a SAMSON Type3271 or
Type3277 Pneumatic Actuator. It can also
be combined with other actuators.
The body (1) is designed either with anges
or welding ends (optionally with additional
welding-neck ends). The seat (4) and plug
(5) are installed in the body. The plug stem is
connected to the actuator stem (A7) by stem
connector clamps (A26) and sealed by an
adjustable packing (15). This packing
(formMS) is specially designed for molten
salt service and has an additional zinc-
impregnated coating to protect it against
corrosion and prevent leakage. The valve
can be tted with a bellows seal (22) to
allow it to withstand high temperatures up to
580°C. In this version, a test connection
(42) on the bonnet (2) allows leakage
monitoring.
The springs (A10) in the pneumatic actuator
are located either above or below the dia-
phragm (A4) depending on the selected fail-
safe action. A change in the signal pressure
acting on the diaphragm causes the plug to
move. The actuator size is determined by the
diaphragm area.
The medium ows through the valve in the
direction indicated by the arrow. A rise in
signal pressure causes the force acting on
the diaphragm in the actuator to increase.
The springs are compressed. Depending on
the selected direction of action, the actuator
stem retracts or extends. As a result, the plug
position in the seat changes and determines
the ow rate through the valve.
We recommend the use of positioners with
integrated diagnostic rmware (see
section3.3) for valves used for on/off
service. The partial stroke test included in this
software helps prevent a shut-off valve
normally in its end position from seizing up
or getting jammed.
Molten salt
Molten salt is used in heat recovery plants
instead of organic heat transfer oils. Molten
salt remains liqueed at temperatures up to
almost 600°C. It is neither ammable nor
toxic. It has a higher heat capacity than con-
ventional heat transfer media.
An exact temperature control and monitoring
of molten salt is essential since it solidies
very quickly as it cools down. For this pur-
pose, the bonnet (2) of the valve is designed
with a connection for a temperature sensor.
Fail-safe action
The fail-safe position of the control valve up-
on air supply or control signal failure de-
pends on the actuator used (see associated
actuator documentation).
Depending on how the compression springs
are arranged in the SAMSON Type3271
and Type3277 Pneumatic Actuator, the
valve has one of two different fail-safe posi-
tions:
Tip

3-2 EB 8052-1 EN
Design and principle of operation
−Actuator stem extends (FA)
When the signal pressure is reduced or
the air supply fails, the springs move the
actuator stem downward and close the
valve. The valve opens when the signal
pressure is increased enough to over-
come the force exerted by the springs.
−Actuator stem retracts (FE)
When the signal pressure is reduced or
the air supply fails, the springs move the
actuator stem upwards and open the
valve. The valve closes when the signal
pressure is increased enough to over-
come the force exerted by the springs.
The actuator's direction of action can be re-
versed, if required. Refer to the mounting
and operating instructions of the pneumatic
actuator:
uEB8310-X for Type3271 and Type3277
Tip
Legend for Fig.3-1
1 Body
2Bonnet
3Yoke
4Seat
5 Plug
8Threaded bushing
(packing nut)
9 Stem connector nut
10 Lock nut
14 Body nut
15 Packing
17 Body gasket
22 Bellows seal
37 Plug stem with bel-
lows seal
42 Test connection
84 Travel indicator scale
92 Castellated nut
A4 Diaphragm
A7 Actuator stem
A8 Ring nut
A10 Spring
A16 Vent plug
A26 Stem connector
clamps
S Signal pressure con-
nection

EB 8052-1 EN 3-3
Design and principle of operation
9
10
8
92
3
2
5
4
15
14
17
1
4
5
2
92
8
10
9
1
17
14
3
A16
A10
A4
S
A7
84
A26
A8
22
37
15
42
Connection for tem-
perature sensor
Fig.3-1: Type3251 Valve for molten salt service: with welding ends, bellows seal and Type3271
Pneumatic Actuator (left) · Standard version with anges (right)

3-4 EB 8052-1 EN
Design and principle of operation
3.1 Versions
Bellows seal
A bellows seal can be tted to the standard
valve version for high temperatures up to
580°C.
Actuators
In these instructions, the preferable combina-
tion with a SAMSON Type3271 or
Type3277 Pneumatic Actuator is described.
The pneumatic actuator (with or without
handwheel) can be replaced by another
pneumatic actuator in a different size, but
with the same travel.
ÎObserve the maximum permissible actu-
ator force.
If the travel range of the actuator is larger
than the travel range of the valve, the spring
assembly in the actuator must be preloaded
so that the travel ranges match. See associ-
ated actuator documentation.
The basic pneumatic actuator can be re-
placed by an actuator with additional hand-
wheel, an electric actuator or a pneumatic
piston actuator.
3.2 Additional ttings
Temperature sensor
A sensor measures the components' tem-
perature to determine whether the minimum
temperature at least prevails in order to keep
the molten salt in the liqueed state.
ÎAdditional instructions on the tempera-
ture sensor can be found in the associat-
ed documentation.
Electric trace heating
An electric trace heating is used to heat the
pipeline and valve (in particular, the bellows
and packing area) to a predetermined tem-
perature to prevent the process medium from
crystallizing.
ÎSet the trace heating to keep the process
medium at least 50°C (122°F) above
the salt's melting point.
ÎAdditional instructions on the electric
trace heating can be found in the associ-
ated documentation.
Heating jacket
The control valve can be tted with a heating
jacket on request.
Bypass and shut-off valves
We recommend installing a shut-off valve
both upstream of the strainer and down-
stream of the valve and installing a bypass
line. The bypass ensures that the plant does
not need to be shut down for service and re-
pair work on the valve.
Test connection
Versions with bellows seal tted with a test
connection (G
1
/
8
) at the top ange allow the
sealing ability of the bellows to be moni-
tored.
Particularly for liquids and vapors, we rec-
ommend installing a suitable leakage indica-
tor (e.g. a contact pressure gauge, an outlet
to an open vessel or an inspection glass).
Note

EB 8052-1 EN 3-5
Design and principle of operation
Safety guard
For operating conditions that require in-
creased safety (e.g. in cases where the valve
is freely accessible to untrained staff), a safe-
ty guard must be installed to rule out a crush
hazard arising from moving parts (actuator
and plug stem). Plant operators are responsi-
ble for deciding whether a guard is to be
used. The decision is based on the risk posed
by the plant and its operating conditions.
Noise reduction
Trims with ow dividers can be used to re-
duce noise emission (see uT8081).
3.3 Valve accessories
Information Sheet uT8350
3.4 Technical data
The nameplates on the valve and actuator
provide information on the control valve ver-
sion. See the 'Markings on the device' sec-
tion.
More information is available in Data Sheet
uT8052.
Noise emissions
SAMSON is unable to make general state-
ments about noise emissions. The noise emis-
sions depend on the valve version, plant fa-
cilities and process medium.
Note
Table 3-1: Technical data
Type3251 Valve for molten salt service
Material Body A351CF8C
Process medium Molten salt
Minimum
temperature
Process medium Depending on the melting point
Valve components 50°C above melting point
Temperature range Standard version –10 to +400°C (14 to 752°F)
With bellows seal –10 to +580°C (14 to +1076°F)
Leakage class According to ANSI/
FCI70-2 IV
Conformity ·

3-6 EB 8052-1 EN
Design and principle of operation
Dimensions and weights
Table 3-2 to Table 3-5 provide an overview of the dimensions and weights of the standard
version of Type3251 Valve. Table 3-6 to Table 3-9 provide an overview of the dimensions
and weights of the Type3251 Valve with bellows seal. The lengths and heights are dened in
the dimensional drawings on page3-7 and are based on a valve combined with a
SAMSON Type3271 or Type3277 Actuator.
Table 3-2: Dimensions of Type3251 Valve, up to NPS6
Valve NPS ½ 1 1½ 2 34 6
DN 15 25 40 50 80 100 150
Length L
(anges RF
and weld-
ing ends)
Class150 in 7.25 7.25 8.75 10.00 11.75 13.88 17.75
mm 184 184 222 254 298 352 451
Class300 in 7.50 7.75 9.25 10.50 12.50 14.50 18.62
mm 190 197 235 267 318 368 473
Class600 in 8.00 8.25 9.88 11.25 13.25 15.50 20.00
mm 203 210 251 286 337 394 508
Class900 in 8.50 10.00 12.00 14.50 15.00 18.00 24.00
mm 216 254 305 368 381 457 610
Height H4
Class
150-600
in 5.98 5.98 6.46 8.54 8.74 9.53 12.36
mm 152 152 164 217 222 242 314
Class900 in 7.32 7.32 7.68 9.88 8.74 9.53 12.36
mm 186 186 195 251 222 242 314
H8 for
actuator
350cm² in 9.45 9.45 9.45 9.45 9.45 9.45 –
mm 240 240 240 240 240 240
355cm² in 9.45 9.45 9.45 9.45 9.45 9.45 16.46
mm 240 240 240 240 240 240 418
700cm² in 9.45 9.45 9.45 9.45 9.45 9.45 16.46
mm 240 240 240 240 240 240 418
750cm² in 9.45 9.45 9.45 9.45 9.45 9.45 16.46
mm 240 240 240 240 240 240 418