Samson 3241-7 Service manual

Pneumatic Control Valves
Type 3241-1 and Type 3241-7
Mounting and
Operating Instructions
EB 8015 EN
Edition September 2009
Fig. 1 · Type 3241 Valve with Type 3271 Actuator and with Type 3277 Actuator
Type 3241-7
Type 3241-1

Contents Page
1 Design and principle of operation. . . . . . . . . . . . . . . . . . . . 4
2 Assembling valve and actuator. . . . . . . . . . . . . . . . . . . . . . 4
2.1 Assembly and adjustment . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Pretensioning springs in actuator version “Actuator stem extends”. . . . . 7
2.3 Valve and actuator with different rated travels . . . . . . . . . . . . . . 8
3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Mounting position. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Signal pressure line . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Strainer, bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 Test connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Maintenance – Replacing parts . . . . . . . . . . . . . . . . . . . . . 10
5.1 Standard valve version. . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1.1 Stuffing box packing. . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1.2 Seat and/or plug . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2 Valve with extension bonnet or metal bellows seal . . . . . . . . . . . 13
5.2.1 Stuffing box packing. . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2.2 Plug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2.3 Seat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.4 Metal bellows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.5 Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3 Replacing the collar or seal . . . . . . . . . . . . . . . . . . . . . . 16
6 Material identification . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.1 Identification marks . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.2 Seat code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7 Description of nameplates . . . . . . . . . . . . . . . . . . . . . . . 20
8 Customer inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2EB 8015 EN
Contents
Note! Non-electrical control valves which do not have a valve body lined with an insulating
material coating do not have their own potential ignition source according to the risk assess-
ment in the rare incident of an operating fault, corresponding to EN 13463-1: 2001 para-
graph 5.2, and therefore do not fall within the scope of the European Directive 94/9/EC.
Refer to paragraph 6.3 of EN 60079-14:1977 VDE 0165 Part 1 concerning connection to
equipotential bonding system.
These Mounting and Operating Instructions apply also to Type 3246 Globe Valve
(Class 150 and 300) in conjunction with Data Sheet T 8046-1 EN.

EB 8015 EN 3
Safety instructions
General safety instructions
4
The control valve may only be mounted, started up or serviced by fully
trained and qualified personnel, observing the accepted industry codes and
practices. Make sure employees or third persons are not exposed to any
danger. All safety instructions and warnings in these mounting and
operating instructions, particularly those concerning assembly, start-up and
maintenance, must be observed.
4
The control valves fulfill the requirements of the European Pressure
Equipment Directive 97/23/EC. Valves with a CE marking have a
declaration of conformity that includes information about the applied
conformity assessment procedure. The declaration of conformity is available
on request.
4
For appropriate operation, make sure that the control valve is only used in
areas where the operating pressure and temperatures do not exceed the
operating values which are based on the valve sizing data submitted in the
order. The manufacturer does not assume any responsibility for damage
caused by external forces or any other external influence! Any hazards
which could be caused in the control valve by the process medium,
operating pressure, signal pressure or by moving parts are to be prevented
by means of the appropriate measures.
4
Proper shipping and appropriate storage are assumed.
Caution!
4
For installation and maintenance work on the valve, make sure the relevant
section of the pipeline is depressurized and, depending on the process
medium, drained as well. If necessary, allow the control valve to cool down
or warm up to reach ambient temperature prior to starting any work on the
valve.
4
Prior to performing any work on the valve, make sure the supply air and
control signal are disconnected or blocked to prevent any hazards that could
be caused by moving parts.
4
Special care is needed when the actuator springs are preloaded. These
actuators are labeled correspondingly and can also be identified by three
long bolts at the bottom of the actuator. Prior to starting any work on the
valve, you must relieve the compression from the preloaded springs.

1 Design and principle of opera-
tion
The Type 3241-1 and Type 3241-7 Pneu-
matic Control Valves consist of a Type 3241
single-seated Globe Valve and either a
Type 3271 or Type 3277 Pneumatic Actua-
tor.
Thanks to the modular design, the actuators
can be exchanged, and the standard version
of the valve can be supplemented to form a
version with extension bonnet or metal bel-
lows seal.
In the micro-flow valve version, a micro-trim
element is installed in the valve body instead
of the usual seat-plug assembly.
The process medium flows through the valve
in the direction indicated by the arrow. The
position of the plug (3) determines the flow
through the valve seat (2). The position of
the plug (3) is changed by the signal pres-
sure acting on the diaphragm of the actua-
tor (bench range). Plug (3) and actuator
stem (8.1) are connected by the stem con-
nector (7) and sealed by the spring-loaded
ring packing (4.2).
Fail-safe position
The control valve provides two different
fail-safe positions depending on the ar-
rangement of the springs in the actuator:
Actuator stem extends
When the signal pressure is reduced or the
power supply or signal fails, the springs
move the actuator stem downwards and
close the valve.
When the signal pressure increases again,
the valve opens acting against the force of
the springs.
Actuator stem retracts
When the signal pressure is reduced or the
power supply or signal fails, the springs
move the actuator stem upwards and open
the valve.
When the signal pressure increases again,
the valve closes acting against the force of
the springs.
2 Assembling valve and actuator
The basic pneumatic actuator can be re-
placed by an electric actuator or a pneu-
matic actuator with additional handwheel.
A pneumatic actuator (with or without
handwheel) can be exchanged for another
pneumatic actuator in a different size.
If, in the valve-actuator assembly, the travel
range of the actuator is larger than the
travel range of the control valve, the actua-
tor springs are preloaded by the manufac-
turer so that the travels match.
2.12.1 Assembly and adjustment
If the valve and actuator have not been
pre-assembled by the manufacturer, or if the
actuator of a valve is to be replaced by an
actuator of another type or another size,
proceed as described below.
1. Unscrew the lock nut (6.2) and stem con-
nector nut (6.1).
Firmly press the plug together with the
plug stem into the seat ring. Make sure
the large V-shaped port of the V-port
plug faces towards the valve outlet.
Thread the stem connector nut and lock
nut downwards.
4EB 8015 EN
Design and principle of operation

EB 8015 EN 5
Assembling valve and actuator
Fig, 2 · Sectional drawings
1. Valve body
1.1 Nuts
1.2 Gasket
2 Seat
3 Plug
4.1 Spring
4.2 Packing
5 Valve bonnet
5.2 Threaded bushing
5.3 Travel indicator scale
6 Plug stem
6.1 Stem connector nut
6.2 Lock nut
6.3 Yoke
(DN 200 to DN 300)
7 Stem connector
8 Actuator
8.1 Actuator stem
8.2 Nut
8
5
5.3
7
6.1
6.2
6
5.2
4.2
4.1
8.2
8.1
1.1
1
2
3
1.2
Type 3271 Actuator
Type 3241 Valve
Micro-trim element
15 Plug stem
16 Valve plug
17 Seat body
18 Spring
19 Seat nut
15
16
17
18
19

6EB 8015 EN
Assembling valve and actuator
Fig. 3 · Sectional drawings of Type 3241-7 and valve body DN 200 to DN 300
8
8.1
8.2
7
6.1
1.1
4.1
1.2
5
3
2
1
4.2
6
5.2
6.2
5.3
6.3
1 Valve body
1.1 Nuts
1.2 Gasket
2 Seat
3 Plug
4.1 Spring
4.2 Packing
5 Valve bonnet
5.2 Threaded bushing
5.3 Travel indicator scale
6 Plug stem
6.1 Stem connector nut
6.2 Lock nut
6.3 Yoke (DN 200 to DN 300)
7 Stem connector
8 Actuator
8.1 Actuator stem
8.2 Nut
Type 3277 Actuator

2. Remove the stem connector clamps (7)
and the ring nut (8.2) from the actuator
(8). Slide the ring nut over the plug stem.
3. Place actuator onto the valve bonnet (5)
and secure with the ring nut (8.2).
4. Read bench range (or bench range with
pre-loaded springs) and fail-safe action
from the actuator's nameplate (e.g. 0.2
to 1 bar and "Actuator stem extends").
The lower value of the bench range
(0.2 bar) corresponds to the lower bench
range value to be adjusted; the upper bench
range value (1 bar) corresponds to the
upper bench range value. The fail-safe ac-
tion "Actuator stem extends" (FA) or "Actua-
tor stem retracts" (FE) is indicated on the
Type 3271 Actuator. The Type 3277 Actua-
tor bears the corresponding symbol.
5. For actuators with "Actuator stem ex-
tends", apply a signal pressure to the
lower diaphragm chamber which corre-
sponds to the lower bench range value
(e.g. 0.2 bar).
For actuators with "Actuator stem re-
tracts", apply a signal pressure to the
upper diaphragm chamber which corre-
sponds to the upper bench range value
(e.g. 1 bar).
6. Thread down the stem connector nut
(6.1) by hand until it makes contact with
the actuator stem (8.1). Then, turn it an-
other 1/4 turn and secure this position
with the lock nut (6.2).
7. Position the stem connector clamps (7)
and screw tight. Align the travel indica-
tor scale (5.3) with the tip of the stem
connector.
Note on disassembling an actuator!
Before disassembling an actuator with
fail-safe action "Actuator stem extends" and
particularly an actuator with preloaded
springs, apply a pressure to the lower signal
pressure connection that slightly exceeds the
lower bench range value (see nameplate of
the actuator), so that you can loosen the ring
nut (8.2).
2.2 Pretensioning springs in
actuator version “Actuator
stem extends”
To achieve a greater positioning force, the
springs in actuators with "Actuator stem ex-
tends" can be preloaded with up to 12.5 %
(actuator sizes 120 and 240 cm²) or up to
25 % (350 cm² and higher) of their travel or
bench range.
Example:
If the springs are preloaded with, for exam-
ple, 0.1 bar for a bench range of 0.2 to
1 bar, the bench range is shifted by 0.1 bar
to result in a bench range of 0.3 to 1.1 bar
(0.1 bar corresponds to a preload of
12.5 %).
When adjusting the valve, the lower bench
range is to be set to 0.3 bar. Make sure the
new bench range of 0.3 to 1.1 bar is indi-
cated on the nameplate as the bench range
with preloaded springs!
EB 8015 EN 7
Assembling valve and actuator

2.3 Valve and actuator with
different rated travels
Actuator version "Actuator stem extends"
Note!
Valves that have a travel smaller than the
rated travel of the actuator always need to
use preloaded springs.
Example:
Valve DN 100 with 30 mm rated travel and
1400 cm² actuator with 60 mm rated travel,
0.4 to 2 bar bench range.
1. Set the signal pressure required for
tensioning the springs above the signal
pressure of 1.2 bar (1.2 to 2 bar range)
which corresponds to the mid actuator
travel (30 mm) to 1.6 bar.
2. Thread stem connector nut (6.1) until it
touches the actuator stem.
3. Secure the position with lock nut and at-
tach stem connector as described in sec-
tion 2.1.
4. Enter the 1.6 to 2.4 bar bench range
valid for the mounted valve on the
nameplate of the actuator.
Actuator version "Actuator stem retracts"
Note!
The springs in the actuator version “Actuator
stem retracts” cannot be preloaded!
If a valve is to be attached to a larger actua-
tor (rated travel of actuator larger than the
rated travel of the valve), just the first half of
the bench range of the actuator can be
used.
Example:
Valve DN 100 with 30 mm rated travel and
1400 cm² actuator with 60 mm rated travel,
0.4 to 1 bar bench range:
A useable bench range of 0.2 to 0.6 bar is
available for the half valve range.
Caution!
Actuators which have been
preloaded by the manufacturer
without an attached valve are
marked with a label.
In addition, you will notice three
extended bolts on the bottom
diaphragm case. They enable you to
evenly relieve the compressed
springs when disassembling the
actuator.
8EB 8015 EN
Assembling valve and actuator

3 Installation
3.1 Mounting position
The valve can be mounted in any desired
position. However, vertical installation with
the actuator pointing upwards is preferable
for valves in nominal size DN 100 or larger
to facilitate maintenance.
For valves with extension bonnet or metal
bellows seal, or for actuators weighing more
than 50 kg, mount a suitable support or sus-
pension for the actuator.
Note!
The valve must be installed with the least
amount of vibrations possible and without
any stress.
Piping design
To allow the control valve to work properly,
the pipeline upstream and downstream of
the valve should be straight and free of ob-
structions for a length of at least 6 times the
pipe diameter (DN).
Contact SAMSON if this length cannot be
met during installation.
Clean out the pipeline thoroughly prior to in-
stalling the valve.
Note!
Valves that should meet the requirements of
NACE MR 0175 standard should not be in-
sulated.
3.2 Signal pressure line
Connect the signal pressure line to the lower
diaphragm case for valves with actuator
version "Actuator stem extends" and to the
upper diaphragm case for valves with actu-
ator version "Actuator stem retracts".
The lower signal pressure connection of the
Type 3277 Actuator is located at the side of
the yoke of the lower diaphragm case.
3.3 Strainer, bypass
We recommend you to install a SAMSON
Type 2 Strainer upstream of the valve body.
We also recommend to install a shut-off
valve both upstream of the strainer and
downstream of the valve, as well as a by-
pass, so that you do not need to shut down
the plant for maintenance.
3.4 Test connection
If there is a test connection (G 1/8) at the
upper flange of a valve version with metal
bellows seal (Fig. 6), you can check the
tightness of the bellows there.
Particularly for liquids and vapors, we rec-
ommend you to install a suitable leak indica-
tor at the test connection, such as a contact
pressure gauge, an outlet into an open ves-
sel or an inspection window.
4 Operation
(e.g. reversing the fail-safe action of the ac-
tuator etc.)
For details concerning operation, see
Mounting and Operating Instructions
EB 8310 EN for the Type 3271 Pneumatic
Actuator and
EB 8311 EN for the Type 3277 Pneumatic
Actuator.
EB 8015 EN 9
Installation

5 Maintenance – Replacing parts
The control valve is subject to natural wear,
especially at the seat, plug and packing.
Depending on the application, the valve
needs to be checked regularly to prevent
against possible failures.
If leakage occurs, this could be caused by a
damaged packing or a defective metal bel-
lows.
If the valve does not seal properly, the tight
shut-off may be impeded by dirt or other im-
purities caught between the seat and plug,
or by damaged seating surfaces.
Remove the parts, clean them thoroughly
and replace them with new ones, if neces-
sary.
Note!
When mounting the bonnet, the large
V-shaped port of the V-port plug must face
towards the valve outlet.
Caution!
Before servicing or disassembling the
control valve, depressurize the con-
cerned section of the plant and drain
it, if necessary, depending on the
medium used. Switch off the signal
pressure for the actuator and remove
the signal pressure line. As valves
are not free of cavities, there might
still be residual medium in the valve.
This applies, in particular, for valve
versions with extension bonnet and
metal bellows seal.
Caution!
On performing any work on the valve, first
shut off the signal pressure, disconnect the
signal pressure line and remove the actua-
tor.
Note!
Suitable seat and special tools as well as the
appropriate tightening torques required for
installation are listed in EB 029 EN (formerly
WA 029 EN). The instructions can be
viewed on the Internet at
www.samson.de/pdf_en/e00290en.pdf.
Removing the actuator:
1. Before disassembling an actuator with
fail-safe action "Actuator stem extends"
and particularly an actuator with
preloaded springs, apply a pressure to
the lower signal pressure connection that
slightly exceeds the lower bench range
value (see nameplate), so that you can
remove the ring nut (8.2). Remove the
stem connector clamps (7) and the ring
nut (8.2).
2. Remove the actuator from the valve bon-
net.
10 EB 8015 EN
Maintenance – Replacing parts