Samson 2422 series Service manual

Mounting and
Operating Instructions
EB 2549 EN
Edition January 2016
Type2422/2425 Excess Pressure Valve
Self-operated Pressure Regulators
Type2422/2425 Excess Pressure Valve

Denition of signal words
DANGER!
Hazardous situations which, if not
avoided, will result in death or serious
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 2549 EN

Contents
EB 2549 EN 3
1 General safety instructions .............................................................................4
2 Process medium and scope of application .......................................................5
2.1 Transportation and storage .............................................................................5
3 Design and principle of operation ..................................................................6
4 Installation ....................................................................................................8
4.1 Assembly ......................................................................................................8
4.2 Mounting position ..........................................................................................9
4.3 Notes on installation ......................................................................................9
4.4 Control line, condensation chamber and needle valve .....................................10
4.5 Strainer .......................................................................................................11
4.6 Shut-off valve ...............................................................................................11
4.7 Pressure gauge ............................................................................................11
5 Operation ...................................................................................................12
5.1 Start-up .......................................................................................................12
5.2 Adjusting the set point ..................................................................................12
5.3 Decommissioning .........................................................................................13
6 Maintenance and troubleshooting ................................................................13
6.1 Replacing the operating diaphragm ..............................................................13
7 Nameplate ..................................................................................................14
8 Customer service .........................................................................................15
9 Dimensions .................................................................................................16
10 Technical data .............................................................................................18
Contents Page

4 EB 2549 EN
General safety instructions
1 General safety instructions
−The regulator must be mounted, started up or serviced by fully trained and
qualied personnel only; the accepted industry codes and practices are to
be observed. Make sure employees or third persons are not exposed to any
danger.
−All safety instructions and warnings given in these mounting and operating
instructions, particularly those concerning installation, start-up and mainte-
nance, must be strictly 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 dangers due to their specialized training, their
knowledge and experience as well as their knowledge of the applicable
standards.
−The regulators comply with the requirements of the European Pressure Equip-
ment Directive 97/23/EC. Devices with a CE marking have a declaration of
conformity, which includes information about the applied conformity assess-
ment procedure. This declaration of conformity can be provided on request.
−To ensure appropriate use, only use the regulator in applications where the
operating pressure and temperatures do not exceed the specications used
for sizing the regulator at the ordering stage.
−The manufacturer does not assume any responsibility for damage caused by
external forces or any other external factors.
−Any hazards that could be caused in the regulator by the process medium,
operating pressure or by moving parts are to be prevented by taking appro-
priate precautions.
−Proper transport, storage, installation, operation and maintenance are as-
sumed.
Note:
Non-electric actuators and control valve versions do not have their own
potential ignition source according to the ignition risk assessment stipulat-
ed in EN13463-1: 2009, section 5.2, even in the rare incident of an op-
erating fault. Therefore, they do not fall within the scope of Directive
94/9/EC. For connection to the equipotential bonding system, observe the
requirements specied in section 6.3 of EN60079-14 (VDE0165 Part 1).


EB 2549 EN 5
Process medium and scope of application
2 Process medium and scope of application
Pressure regulator for liquids, gases and vapors up to 350°C
For controlling the upstream pressure p1 to the adjusted set point. The valve opens when the
upstream pressure rises. The upstream pressure is transmitted to the actuator over a control line
that must be installed on site.
The pressure regulators are not shut-off devices guaranteeing tight shut-off. When closed, these
regulators can have a leakage rate of ≤0.05% of the KVS coefcient.
Overpressure protection must be installed in the plant.
WARNING!
Risk of injury and property damage due to high pressure in the plant.
A suitable overpressure protection must be installed on site in the plant section.
2.1 Transportation and storage
The regulator must be carefully handled, transported and stored. Protect the excess pressure
valve against adverse inuences, such as dirt, moisture or frost, during storage and transpor-
tation.
When regulators are too heavy to be lifted by hand, fasten the lifting sling at a suitable place
on the valve body.
WARNING!
Incorrectly attached lifting slings or supports.
Risk of injury and property damage due to valve falling.
Securely fasten slings or supports to the valve body and secure against slipping.

6 EB 2549 EN
Design and principle of operation
3 Design and principle of op-
eration
See Fig.1 and Fig.2.
The Type2422/2425 Excess Pressure Valve
consists of the Type 2422 Valve and the
Type2425 Actuator. The Type2422 Valve is
available either balanced by a bellows or a
diaphragm.
The excess pressure valve is used to maintain
the pressure upstream of the valve to an ad-
justed set point. The valve opens when the up-
stream pressure rises.
The medium ows through the valve in the di-
rection indicated by the arrow. The position of
the plug (3) determines the ow rate across
the area released between plug and valve
seat (2). The plug stem (4) with the plug is
connected to the top diaphragm stem (8) of
the actuator (10).
The upstream pressure p
1
is regulated by the
positioning springs (11) and the set point ad-
juster (13). When relieved of pressure, the
valve is closed by the force of the set point
springs.
The upstream pressure p1 to be controlled is
tapped upstream of the valve and transmitted
over the control line to the operating dia-
phragm (9) where it is converted into a posi-
tioning force. This force is used to move the
valve plug according to the force of the posi-
tioning springs. When the force resulting from
the upstream pressure p1 rises above the ad-
justed set point, the valve opens proportional-
ly to the change in pressure.
The principle of operation of the
Type2422/2425 Excess Pressure Valve bal-
anced by a bellows or diaphragm only differs
concerning the pressure balancing. The valves
balanced by a diaphragm have a balancing
diaphragm (5.1) instead of a bellows (5). In
both cases, the forces created by the upstream
and downstream pressures that act on the
valve plug are balanced out.
The valves can be supplied with ow divider
StI or StIII. The valve seat must be replaced
on retrotting the ow divider.
The control of vapors and liquids above
150 °C is only possible with a Type 2422
Valve balanced by a bellows. In this case,
condensation chamber (20) is already in-
stalled in the control line1). The needle valve
(18) in the control line is open and lead-
sealed.
Before start-up, ll the condensation chamber
with the process medium at the lling opening
(21) until it overows.
_
1) Only in combination with a control line kit.
Otherwise, the condensation chamber must be
ordered separately (see uT2595).

EB 2549 EN 7
Design and principle of operation
Fig.1: Functional diagram of Type2422/2425 balanced by a bellows
Type 2422 Valve,
balanced by a
bellows
Type2425 Actuator
1
2
3
4
5
6
7
8
9
17
16
11
13
20 21
6.1
19
6.2
18
15
14
8.1
1 Type 2422 Valve
2 Seat (exchangeable)
3 Plug
4 Plug stem
4.1 Actuator stem
5 Balancing bellows
6 Bellows housing
6.1 Vent screw (640cm², bellows
housing)
6.2 Vent screw (connection to
actuator)
7 Coupling nut
8Top diaphragm stem
8.1 Nut
9Operating diaphragm
10 Type2424 Actuator
11 Positioning springs
13 Set point adjuster
14 Bottom diaphragm stem
15 Nuts and bolts
16 Nut
17 Diaphragm plate
18 Control line connection (for
steam including screw joint with
restriction and needle valve)
19 Control line
20 Condensation chamber for tem-
peratures above 150°C and for
steam
21 Filling opening with plug
p1Upstream pressure
p2Downstream pressure
p1p2

8 EB 2549 EN
Installation
4 Installation
See Fig.1 and Fig.2.
4.1 Assembly
Valve and actuator can be assembled before
or after the valve has been installed in the
pipeline.
Î
Relieve the positioning springs of tension
by turning the set point adjuster (13).
ÎPlace the actuator on the bellows housing
and carefully screw it in as far as it will
go. Make sure the control line connection
points toward the upstream pressure side.
Î
Hold the actuator and fasten it to the bel-
lows housing using the coupling nut (7).
Fig.2: Functional diagram of Type2422/2425 balanced by a diaphragm
5.1 Balancing diaphragm
p1Upstream pressure
p2Downstream pressure
Type 2422 Valve,
balanced by a
diaphragm
Type2425 Actuator
5.1
P1P2

EB 2549 EN 9
Installation
4.2 Mounting position
Select the installation location making sure
that the regulator is installed at a distance of
at least six times the nominal size (DN) away
from pipe ttings or instruments that cause
ow turbulence (e.g. pipe bends, manifolds,
pressure measuring points or other valves).
They can change the ow conditions which
may lead to an instable control process espe-
cially in applications with gases, air or steam.
Contact SAMSON to obtain the TV-SK17041
documentation which contains more details on
installation requirements.
4.3 Notes on installation
Install the excess pressure valve in horizontal
pipelines.
−Flush the pipeline thoroughly before in-
stalling the regulator to ensure that no
impurities impair the proper functioning
of the valve, above all the tight shut-off.
−Direction of ow must match the direction
indicated by the arrow on the body.
−Install the regulator free of stress. If nec-
essary, support the pipeline near to the
connecting anges. Do not attach sup-
ports directly to the valve or actuator.
−Install a strainer upstream of the regula-
tor.
−Protect the regulator from icing up when
controlling media that can freeze. If nec-
essary, depressurize and drain the regu-
lator and remove it from the pipeline
while the plant is shut down.
Fig.3: Sample application
1
p
1
p2
3451
2
16
1 Shut-off valve
2 Upstream pressure
gauge
3 Strainer (lter)
4 Type2422/2425
Excess Pressure Valve
5 Downstream pressure
gauge
6 Bypass piping
p1Upstream pressure
p2Downstream pressure

10 EB 2549 EN
Installation
Mounting position
Valve balanced by a bellows/diaphragm
−Actuator facing downward
Pressure testing of the plant · The pressure
must not exceed the maximum permissible
pressure of the regulator and plant on testing
the pressure of the plant when the regulator is
already installed. An excessive test pressure
can damage the operating diaphragm in the
actuator.
NOTICE
Uncontrolled excess pressure in the
plant may damage the operating dia-
phragm.
The maximum permissible pressure at
the actuator must not exceed the pres-
sure specied in Table1.
Table1: Max. perm. pressure at actuator
Actuator area Max. perm. pressure
640cm² 1.5bar
320cm² 3bar
To prevent damage to the diaphragm, take
one of following precautions:
−Remove the regulator from the pipeline
or isolate the regulator in the pipeline
and install a bypass (see Fig.3) or
−Detach the control line and seal the
openings with end plugs or
−Install a shut-off valve in the control line.
4.4 Control line, condensation
chamber and needle valve
Control line · A control line must be provided
at the site of installation, e.g. a
3
/
8
“ pipe for
steam or an Ø8x1 or Ø6x1mm copper
pipe for air or water.
Connect the control line to the upstream line
(p1) at least one meter away from the valve in-
let. If a manifold is located upstream of the ex -
cess pressure valve, connect the valve to the
manifold, even if it is several meters away. If
the upstream line is extended by a conical ex-
pansion piece, connect the control line in the
expanded section of the line. Weld the control
line at the side in the middle of the pipe, in-
clining at a ratio of approximately 1:10 up to
the condensation chamber.
Weld the line coming from the pressure tap-
ping point to the
3
/
8
“ pipe socket on the cham-
ber. Install the condensation chamber at the
highest point of the pipeline. Consequently,
the control line between condensation cham-
ber and actuator must also be installed with a
downward slope. In this case, use a
3
/
8
“ pipe
with screw ttings.
If the control line connection is located below
the middle of the valve inlet ange, arrange
the condensation chamber at the same level
as the inlet ange. In this case, use a pipe
which is at least ½“ in size for the control line
from the tapping point to the condensation
chamber.
If the control line is connected above the mid-
dle of the valve inlet ange, install the conden-
sation chamber at the same level as the up-
stream pressure tapping point. The additional