Samson 250 series Service manual

Mounting and
Operating Instructions
EB 8053 EN
Edition June 2014
Type 3252 High-pressure valve with Type3277 Pneumatic Actuator and Type3767 Electropneumatic
Positioner
Series 250
Type3252‑1 and Type3252‑7
Pneumatic Control Valves

Denition of signal words
DANGER!
Hazardous situations which, if not
avoided, will result in death or seri-
ous injury
WARNING!
Hazardous situations which, if not
avoided, could result in death or seri-
ous injury
NOTICE
Property damage message or mal-
function
Note:
Additional information
Tip:
Recommended action

2 EB 8053 EN

Contents
EB 8053 EN 3
1 General safety instructions.............................................................................5
2 Design and principle of operation ..................................................................6
1.1 Fail-safe position............................................................................................6
1.2 Replacing the actuator....................................................................................6
3 Assembling and adjusting the valve and actuator ...........................................8
1.1 Reversal of the operating direction ..................................................................9
4 Installation....................................................................................................9
1.2 Signal pressure line........................................................................................9
5 Troubleshooting...........................................................................................10
1.1 Removing the actuator from the valve ............................................................10
1.2 Replacing the packing in standard valves.......................................................10
1.2.1 Plug............................................................................................................11
1.2.2 Seat............................................................................................................11
1.1 Replacement in valve with insulating section or bellows seal ............................12
1.1.1 Packing.......................................................................................................12
1.1.2 Plug............................................................................................................12
1.1.3 Metal bellows ..............................................................................................12
1.1.1 Reassembly .................................................................................................14
6 Appendix....................................................................................................15
1.1 Nameplate ..................................................................................................15
1.2 Customer inquiries .......................................................................................15

4 EB 8053 EN

EB 8053 EN 5
General safety instructions
1 General safety instructions
For your own safety, follow these instructions concerning the mounting, start-up and opera-
tion of the valve:
−The valve is to be mounted, started up or operated only by trained and experienced per-
sonnel familiar with the product.
−According to these mounting and operating instructions, trained personnel refers to indi-
viduals who are able to judge the work they are assigned to and recognize possible dan-
gers due to their specialized training, their knowledge and experience as well as their
knowledge of the applicable standards.
−Any hazards that could be caused in the valve by the process medium, the signal pres-
sure or by moving parts are to be prevented by taking appropriate precautions.
−To ensure appropriate use, only use the valve in applications where the operating pres-
sure and temperatures do not exceed the specications used for sizing the valve at the or-
dering stage.
To avoid damage to any equipment, the following also applies:
−Proper shipping and storage are assumed.

6 EB 8053 EN
Design and principle of operation
2 Design and principle of oper-
ation
The Type 3252 Valve with a globe-style or
angle-style body can be combined with
either a Type3271 Pneumatic Actuator or a
Type3277 Pneumatic Actuator with integral
positioner attachment.
The standard valve bodies have threaded
ends with either G or NPT thread.
Special valve versions are designed with
either weld-on anges or welding ends for
welding into the pipeline.
The modular design allows the actuators to
be exchanged and an insulating section or
metal bellows to be tted to the standard
valve version
The medium ows through the valve in the
direction indicated by the arrow. The plug is
moved by changing the signal pressure act-
ing on the diaphragm of the actuator. The
plug stem (6) is connected to the actuator
stem (8.1) by the stem connector (7).
The plug stem is sealed by a spring-loaded
V-ring packing (4.2).
2.1 Fail-safe position
Depending on how the springs are arranged
in the actuator, the control valve assumes
one of two different fail-safe positions:
Actuator stem extends (fail-close): When the
pressure is relieved from the diaphragm or
the supply air fails, the actuator springs close
the valve.
Actuator stem retracts (fail-open): When the
pressure is relieved from the diaphragm or
the supply air fails, the actuator springs
open the valve.
2.2 Replacing the actuator
A pneumatic actuator can be replaced by
another pneumatic actuator in a different
size.
If the travel range of the actuator is larger
than the travel of the valve, the springs in the
actuator are preloaded by SAMSON so that
the travel ranges match.

EB 8053 EN 7
Design and principle of operation
1Valve body
1.1 Gasket
2 Seat
4.1 Spring
4.2 Packing
4.3 Washer
5Valve bonnet
5.1 Guide bushing
5.2 Threaded bushing
5.3 Yoke
5.4 Ring nut
5.5 Screw
5.6 Anti-rotation xture
5.7 Travel indicator
scale
6 Plug stem
6.1 Stem connector nut
6.2 Lock nut
7 Stem connector
8.1 Actuator stem
8.2 Ring nut
8.3 Springs
8.4 Rolling diaphragm
9Signal pressure con-
nection
10 Vent plug
10
9
8.4
8.3
8.2
8.1
5.3
5.7
7
6.1
6.2
5.2
5.1
2
1
5.4
4.1
1.1 5.5
5.6
5
4.2
4.3
6
9
Fig.1: Sectional drawing of Type3252 Valve with Type3271 Actuator (120cm²)

8 EB 8053 EN
Assembling and adjusting the valve and actuator
3 Assembling and adjusting the
valve and actuator
Proceed as follows if the original actuator is
to be replaced by an actuator of another
type or size:
1. Loosen the lock nut(6.2) and stem con-
nector nut(6.1) on the valve.
2. Press the plug together with the plug stem
rmly into the seat. Thread down the lock
nut and stem connector nut.
3. Remove the clamps of the stem connector
(7) and the ring nut (8.2) from the actua-
tor. Slide the ring nut over the plug stem.
4. Place the actuator onto the yoke(5.3)
and secure it with the ring nut(8.2).
5. Read the bench range or (signal pressure
range with preloaded springs) and oper-
ating direction of the actuator specied
on the actuator nameplate.
Note:
The fail-safe action "actuator stem
extends" or "actuator stem retracts"
is marked by FA or FE on the
Type3271 Actuator, and by a corre-
sponding symbol on the nameplate
of the Type3277 Actuator.
The lower value corresponds to the
lower bench range value to be ad-
justed, whereas the upper value cor-
responds the upper bench range val-
ue.
6. For fail-close actuators, apply a signal
pressure that corresponds to the lower
bench range value (e.g. 0.6bar for a
range between 0.6 and 1bar) to the sig-
nal pressure connection on the bottom
diaphragm chamber.
For fail-open actuators, apply a signal
pressure that corresponds to the upper
bench range value (e.g. 0.6bar for a
range between 0.2 and 0.6bar) to the
signal pressure connection on the top di-
aphragm chamber.
7. Screw on the stem connector nut(6.1) by
hand until it touches the actuator stem
(8.1). Then turn it a further ¼turn and
secure this position with the lock nut(6.2)
8. Position clamps of the stem connector (7)
and screw them tight. Align the travel in-
dicator(5.7) with the tip of the stem con-
nector.
The following applies to removing the actu-
ator:
ÎApply a signal pressure that is slightly
higher than the lower bench range value
(see actuator nameplate) to the signal
pressure connection.
Note:
Actuators with preloaded springs are
labeled correspondingly and can al-
so be identied by three long bolts
protruding from the bottom of the ac-
tuator.



EB 8053 EN 9
Installation
3.1 Reversal of the operating
direction
The operating direction and fail-safe action
of pneumatic actuators can be changed. Re-
fer to the mounting and operating instruc-
tions of the actuator for details on how to
proceed:
−Types 3271 and 3277 Actuator
(120cm²):
u EB 8310-1EN
−Types 3271 and 3277 Actuator (350
and 700cm²):
u EB 8310-6EN
4 Installation
The following applies concerning the instal-
lation of the valve:
ÎThe valve can be mounted in any desired
position. The ow of direction must cor-
respond with the direction indicated by
the arrow on the valve body.
ÎMake sure the valve is installed free of
stress. If necessary, support the pipelines
near the connections.
ÎFlush the pipeline thoroughly before in-
stalling the valve (valve open).
The following points additionally apply to
the version with welding ends:
ÎThe valve must be welded into the pipe-
line by trained personnel observing the
applicable standards.
ÎBefore welding the valve into the pipe-
line, move the plug out of the seat. The
entire valve does not need to be disman-
tled.
ÎBefore start-up, make sure that the valve
is free from weld spatter and other impu-
rities.
4.1 Signal pressure line
Connect the signal pressure line for a valve
with fail-close actuator to the connection on
the bottom diaphragm case, and for a valve
with fail-open actuator to the connection on
the top diaphragm case.
In the Type3277 Actuator, the bottom signal
pressure connection is located at the side of
the yoke under the bottom diaphragm case.

10 EB 8053 EN
Troubleshooting
5 Troubleshooting
External leakage can indicate that the pack-
ing is defective or the metal bellows is defec-
tive (in a version with a bellows seal).
If the valve does not close tightly, tight shut-
off may be impaired by dirt stuck between
the seat and plug or by damaged facings.
ÎIn this case, remove parts, carefully clean
them and renew them, if necessary.
ÎBefore starting any work on the valve
body, rst remove the actuator (see sec-
tion5.1).
WARNING!
Risk of injury due to process medium
escaping under pressure.
Depressurize the relevant section of
the pipeline and, if necessary, drain
it as well. When used at high tem-
peratures, allow the plant section to
cool down to ambient temperature.
Tip:
Before performing maintenance
work, we recommend removing the
valve from the pipeline or the entire
valve construction when the valve is
welded into the pipeline.
5.1 Removing the actuator
from the valve
1. Mount the stem connector clamps (7) be-
tween the actuator stem and the plug
stem.
2. For fail-close actuators, apply a signal
pressure that is higher than the lower
bench range value (see nameplate) to the
actuator so that the ring nut (8.2) can be
unscrewed.
3. Unscrew the ring nut.
4. Disconnect the signal pressure again.
5. Remove the actuator from the valve yoke.
5.2 Replacing the packing in
standard valves
Note:
Contact your nearest SAMSON sub-
sidiary or the SAMSON After-sales
Service department for information
on suitable lubricants.
ÎSee Fig.1 on page 7
If the packing leaks, replace it as follows:
1. Unscrew the ring nut (5.4) and remove
the yoke (5.3) from the valve bonnet.
2. Unscrew the lock nut(6.2) and stem con-
nector nut(6.1). Unscrew the screw (5.5)
for the anti-rotation xture. Remove the
anti-rotation xture (5.6).
3. Undo screws (5) on the valve bonnet. Re-
move the valve bonnet along with the
plug stem (6).
