Samson 3281 Service manual

Translation of original instructions
EB 8251 EN
Edition June 2021
Type 3281 Steam Conditioning Valve · DIN version
In combination with an actuator,
e.g. a Type3271 or Type3277 Pneumatic Actuator

Denition 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 8251 EN
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.

Contents
EB 8251 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
2 Markings on the device ..............................................................................2-1
2.1 Valve nameplate .........................................................................................2-1
2.2 Actuator nameplate.....................................................................................2-2
2.3 Material identication number .....................................................................2-2
2.4 Label when an adjustable packing is installed ...............................................2-2
3 Design and principle of operation ...............................................................3-1
3.1 Fail-safe positions .......................................................................................3-1
3.2 Versions .....................................................................................................3-3
3.3 Additional ttings........................................................................................3-3
3.4 Valve accessories........................................................................................3-4
3.5 Technical data ............................................................................................3-4
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 .................................................................................4-3
4.3.2 Lifting the valve...........................................................................................4-4
4.4 Storing the valve.........................................................................................4-5
5 Installation.................................................................................................5-1
5.1 Installation conditions..................................................................................5-1
5.2 Preparation for installation...........................................................................5-2
5.3 Mounting the device....................................................................................5-3
5.3.1 Mounting the external anti-rotation xture.....................................................5-4
5.3.2 Mounting the actuator onto the valve..........................................................5-13
5.3.3 Installing the valve into the pipeline ............................................................5-14
5.4 Testing the installed valve...........................................................................5-16
5.4.1 Leak test...................................................................................................5-17
5.4.2 Travel motion............................................................................................5-17
5.4.3 Fail-safe position.......................................................................................5-18
5.4.4 Pressure test..............................................................................................5-18

Contents
EB 8251 EN
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 .......................................................................................8-3
9 Servicing....................................................................................................9-1
9.1 Periodic testing ...........................................................................................9-3
9.2 Preparing the valve for service work.............................................................9-5
9.3 Installing the valve after service work............................................................9-5
9.4 Service work...............................................................................................9-6
9.4.1 Replacing gaskets .......................................................................................9-6
9.4.2 Replacing the packing.................................................................................9-8
9.4.3 Replacing the seat and plug.......................................................................9-11
9.4.4 Determining the number of shims required..................................................9-12
9.5 Ordering spare parts and operating supplies ..............................................9-14
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.....................................................................................15-4

EB 8251 EN 1-1
Safety instructions and measures
1 Safety instructions and measures
Intended use
The SAMSON Type3281 Steam Conditioning Valve in combination with an actuator (e.g.
Type3271 or Type3277 Pneumatic Actuator) is designed to regulate the pressure and tem-
perature of steam. The valve is intended for use in for process engineering applications and
thermal plants. The valve with its actuator is designed to operate under exactly dened con-
ditions (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 de-
vice 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. Ac-
cording 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.
Welding operations must only be performed by personnel who has the necessary qualica-
tion to perform the applied welding procedure and handle the materials used.

1-2 EB 8251 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 8251 EN 1-3
Safety instructions and measures
Responsibilities of the operator
Operators are responsible for proper use and compliance with the safety regulations. Opera-
tors are obliged to provide these mounting and operating instructions as well as the refer-
enced documents to the operating personnel and to instruct them in proper operation. Fur-
thermore, 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, directives and regulations
The control valves comply with the requirements of the European Pressure Equipment Direc-
tive 2014/68/EU. Valves with a CE marking have a declaration of conformity, which in-
cludes information about the applied conformity assessment procedure. The 'Certicates' sec-
tion contains this declaration of conformity.
According to the ignition hazard assessment performed in accordance with Clause5.2 of
ISO80079-36, 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
Clause6.4 of EN60079-14 (VDE0165-1).

1-4 EB 8251 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 the
SAMSON Type3271 or Type3277 Pneumatic Actuator
− Mounting and operating instructions for mounted valve accessories (positioner, solenoid
valve etc.)
− 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
− When a substance is used in the device, which is listed as being a substance of very high
concern on the candidate list of the REACH regulation:
Information on safe use of the part affected
uwww.samsongroup.com > About SAMSON > Material Compliance > REACH
If a device contains a substance which is listed as being a substance of very high concern
on the candidate list of the REACH regulation, this circumstance is indicated on the
SAMSON delivery note.
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.

EB 8251 EN 1-5
Safety instructions and measures
1.2 Notes on possible personal injury
WARNING
!
Risk of burn injuries due to hot or cold components and pipelines.
Depending on the process medium, valve components and pipelines may get very hot
or cold and cause burn injuries.
ÎAllow components and pipelines to cool down or warm up to the ambient tempera-
ture.
ÎWear protective clothing and safety gloves.
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.
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 openings 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.

1-6 EB 8251 EN
Safety instructions and measures
WARNING
!
Riskofpersonalinjuryduetoincorrectremovaloftheanti-rotationxtureunderten-
sion.
Once the actuator has been mounted on the valve and the assembly is ready for use,
the clamps of the anti-rotation xture on the plug stem are under tension.
ÎFollow the instructions in this document during mounting or removal.
ÎFirst remove the actuator from the valve or ensure it cannot transmit any forces to
the actuator stem before removing the anti-rotation xture on the plug stem.
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).
Forinstalledvalvesttedwithabellowsseal:Riskofpersonalinjuryduetopressur-
ized components and process medium being discharged.
ÎDo not loosen the screw of the test connection while the valve is pressurized.
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.
Exposure to hazardous substances poses a serious risk to health.
Certain lubricants and cleaning agents are classied as hazardous substances. These
substances have a special label and a material safety data sheet (MSDS) issued by the
manufacturer.
ÎMake sure that an MSDS is available for any hazardous substance used. If neces-
sary, contact the manufacturer to obtain an MSDS.
ÎInform yourself about the hazardous substances and their correct handling.

EB 8251 EN 1-7
Safety instructions and measures
WARNING
!
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.
ÎPickle and blow through the steam pipe.
Risk of valve damage due to unsuitable medium properties.
The valve is designed for steam and cooling water.
ÎMake sure that the steam and cooling water are clean and free of mineral compo-
nents.
ÎInstall strainers.
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).

1-8 EB 8251 EN
Safety instructions and measures
NOTICE
!
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.
ÎIf necessary, keep the valve and the tools used free from solvents and grease.
ÎMake sure that only suitable lubricants are used.

EB 8251 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 pos-
sible characteristics and options that may
appear on a valve nameplate. Only the in-
scriptions relevant to the ordered Type3281
Valve actually appear on the nameplate.
Note
Item Inscription meaning
1Data 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:perfo-
rated 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 8251 EN
Markings on the device
The nameplate (80) is afxed to the yoke of
the valve (see Fig.2-2).
80
Fig.2-2: Location of the nameplate
2.2 Actuator nameplate
See associated actuator documentation.
2.3 Materialidentication
number
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 8251 EN 3-1
Design and principle of operation
3 Design and principle of oper-
ation
The single-seated Type3281 Globe Valve
acts as a steam conditioner and is tted with
a ow divider ST3. The Type3281
Steam-conditioning Valve is preferably com-
bined with a SAMSON Type3271 or
Type3277 Pneumatic Actuator (see
Fig.3-1). It can also be combined with other
actuators.
The seat (4), ow divider (62) and plug with
plug stem (5) are installed in the body (1).
The plug stem is connected to the actuator
stem (A7) by the stem connector clamps
(A26/27) and is sealed by a spring-loaded
V-ring packing (15). Alternatively, an adjust-
able high-temperature packing can be used.
The springs in the pneumatic actuator are lo-
cated either above or below the diaphragm
(A4) depending on the selected fail-safe ac-
tion (see section3.1). A change in the signal
pressure acting on the diaphragm causes the
plug to move. The actuator size is deter-
mined 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 and the pres-
sure p2as well.
The cooling water is fed to the ow divider
(62) through the connecting pipe on the bon-
net (2) and holes in the clamping element
(63). After owing through the cross-section-
al area between seat and plug, the steam
ow reaches its maximum velocity and
comes into contact with the cooling water at
the inner wall of the ow divider. The steam
ow and the entrained water are mixed in
the narrow wire mesh of the ow divider. At
the same time, the steam velocity is reduced,
releasing some of its heat to the water across
the large surface of the wire mesh coil,
which causes it to evaporate quickly. The
steam/water mixture leaves the ow divider
as a ne mist with a high steam content.
Evaporation is completed a short distance
downstream of the steam conditioning valve.
The water atomization described is ensured
over the whole load range since the steam
velocity at the throttling point is independent
of the ow rate.
3.1 Fail-safe positions
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:
Actuator stem extends (FA)
When the signal pressure is reduced or the
air supply fails, the springs move the actua-
tor stem downward and close the valve. The
valve opens when the signal pressure is in-

3-2 EB 8251 EN
Design and principle of operation
1Body
2Bonnet (with connecting pipe)
3Yoke
4Seat
5 Plug (with plug stem)
7 Guide bushing
8Threaded bushing (packing nut)
9 Stem connector nut
10 Lock nut
14 Body nut
15 Packing
17 Body gasket
62 Flow divider ST3
63 Clamping element
84 Travel indicator scale
92 Castellated nut
A4 Diaphragm
A7 Actuator stem
A8 Ring nut
A10 Spring
A26/27 Stem connector clamps
S Signal pressure connection
p1
t1
p2
t2
p3
t3
63
62
4
1
5
17
14
15
92
8
10
9
84
S
3
A26/27
A7
A8
A4
A10
2
7
Superheated
steam
Water
Throttled and
cooled steam
Fig.3-1: Type3281 Valve with Type3271 Pneumatic Actuator

EB 8251 EN 3-3
Design and principle of operation
creased enough to overcome the force exert-
ed by the springs.
Actuator stem retracts (FE)
When the signal pressure is reduced or the
air supply fails, the springs move the actua-
tor stem upwards and open the valve. The
valve closes when the signal pressure is in-
creased enough to overcome the force exert-
ed 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
3.2 Versions
Insulating section
The modular design allows an insulating sec-
tion to be tted to the standard valve version.
Installed valves may have a bellows seal t-
ted on them.
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 a pneumatic actuator with addi-
tional handwheel or by an electric actuator
(see Information Sheet uT8300).
3.3 Additionalttings
Steam trap
Automatic steam traps must be installed at
the lowest point in the upstream and down-
stream lines to ensure proper functioning of
the plant.
Check valve
We recommend installing check valves be-
tween the steam conditioning valve and the
cooling water valve to protect the condensate
system.
Strainers
We recommend installing a SAMSON
strainer upstream of the valve body and in
the inlet pipe for the water supply. It prevents
solid particles in the process medium from
damaging the valve.
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
Tip
Note

3-4 EB 8251 EN
Design and principle of operation
1) Only in installed valves tted with a bellows seal
not need to be shut down for service and re-
pair work on the valve.
Insulation
Control valves can be insulated to reduce
heat energy transfer. Refer to the instructions
in the 'Installation' section.
Test connection1)
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).
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
A further noise reduction can only be
achieved by using additional insulation as
the steam conditioning valve is already
equipped with ow divider3.
3.4 Valve accessories
Information Sheet uT8350
Depending on the excessive heat that radi-
ates from the steam conditioning valve, only
mount valve accessories (e.g. positioners) on
the inlet side of the cooling water valve.
3.5 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8251.
Note

EB 8251 EN 3-5
Design and principle of operation
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.
Table3-1: Technical data for Type3281
Material Cast steel · 1.0619 Cast steel · 1.7357
Valve size DN 50…300
Pressure rating PN 16…160
Type of connection Flanges All DIN EN versions
Welding ends DINEN12627
Seat-plug seal Metal seal or high-performance metal seal
Characteristic Equal percentage or linear
Rangeability 50 : 1
Compliance ·
Temperature ranges · Permissible operating pressures acc. to pressure-temperature diagrams (see
Information Sheet uT8000-2)
Body without insulating section –10 to +220°C · Up to 350°C with high-
temperature packing
Body with insulating section –10 to +400°C –10 to +500°C
Valve plug
Standard Metal seal –10 to +500°C
Balanced with PTFE –10 to +220°C
Balanced with graphite ring –10 to +500°C
Leakage class according to IEC60534-4
Valve plug
Standard
Metal seal IV
High-performance
metal seal V
Balanced with PTFE Standard: IV · High-performance metal seal: V
Balanced with graphite ring IV

3-6 EB 8251 EN
Design and principle of operation
Dimensionsandweights
Table 3-2 and Table 3-3 provide an overview of the dimensions and weights of the standard
version of Type3281 Valve. The lengths and heights in the dimensional drawings are shown
on p.3-7.
Dimensions in mm · Weights in kg
Table3-2: Dimensions of Type3281 · Face-to-face dimensions according to DINEN558
Valve DN 50 80 100 150 200 250 300
Length L
(anges and
welding ends)
PN10 to 40 230 310 350 480 600 730 850
PN63 to 160 300 380 430 550 650 775 900
Height H4 PN16 to 40 217 222 242 314 387 442 655
PN63 to 160 519
H8 for actuator
350cm² 240 240 240 –
355v2cm² 240 240 240 418 –
700cm² 240 240 240 418 418 418 –
750v2cm² 240 240 240 418 418 418 –
1000cm² 295 295 295 418 418 On request
1400-60cm² 295 295 295 418 418 On request
1400-120cm² 480 480 480 503 503 503 1) 650
2800cm² 480 480 480 503 503 503 1) 650
2x2800cm² 480 480 480 503 503 503 1) 650
H2 (DN 100 and
larger with foot)
PN16 to 40 90 100 160 220 250 310 370
PN63 to 160 100 120 180 235 270 300 390
1) H8 = 650 mm with 250 mm seat bore
Table3-3: Weights for Type3281
Valve DN 50 80 100 150 200 250 300
Valve without actua-
tor
PN16 to 40 40 68 85 215 450 On request
PN63 to 160 66 105 140 395 660