Samson 2357-31 Service manual

Self-operated Pressure Regulators
Pressure Build-up Regulator Type 2357-31
with safety function and integrated pressure relief valve
Mounting and
Operating Instructions
EB 2558 EN
Edition March 2010
Type 2357-31 with non-return unit · Connections with soldering
nipples and ball-type bushings

2EB 2558 EN
Contents
CAUTION!
Indicates a hazardous situation which could
lead to personal injury
NOTICE!
Indicates a risk of property damage.
Note! Indicates supplementary explanations,
information and tips
Definitions of the signal words used in these instructions
Contents Page
1 Design and principle of operation . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Process medium, application range . . . . . . . . . . . . . . . . . . . . . 4
2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Mounting position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Shut-off valves, pressure gauges . . . . . . . . . . . . . . . . . . . . . . . 6
3 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Set point adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Decommissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Customer service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

EB 2558 EN 3
Safety instructions
General safety instructions
Observe the following instructions on installation, start-up and operation of the regulators for
your own safety:
4
The regulator is to be assembled, started up or operated only by trained and
experienced personnel familiar with the product. Make sure employees or
third persons are not exposed to any danger.
All safety instructions and warnings in these mounting and operating instruc-
tions, particularly those concerning assembly, start-up and maintenance, must
be observed.
4
According to these mounting and operating instructions, trained personnel is
referred to as individuals who are able to judge the work they are assigned to
and recognize possible dangers due to their specialized training, their knowl-
edge and experience as well as their knowledge of the applicable standards.
4
The regulator fulfils the requirements of the European Pressure Equipment Di-
rective 97/23/EC. Regulators with a CE marking have a declaration of con-
formity 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 regulator is only used in areas
where the operating pressure and temperatures do not exceed the operating
values specified in the order that the valve sizing data are based on. The man-
ufacturer does not assume any responsibility for damage caused by external
forces or any other external influence!
4
Any hazards that could be caused in the regulator by the process medium, the
operating pressure or by moving parts are to be prevented by means of the
appropriate measures.
4
Proper shipping and storage are assumed.
Note! Non-electric valve versions whose bodies are not lined with an insulating
material coating do not have their own potential ignition source according to the
risk assessment stipulated in EN 13463-1:2001, section 5.2, even in the rare inci-
dent of an operating fault. Therefore, such valve versions do not fall within the
scope of Directive 94/9/EC.

1 Design and principle of oper-
ation
Also see Fig. 1 on page 5.
Depending on the direction of flow, the regula-
tor functions as a pressure build-up regulator
with safety function (direction of flow A →B)
or as a pressure relief valve (direction of flow
B→C). The position of the pressure build-up
plug (2) determines the flow rate across the
area released between the plug and seat.
The pressure regulator is designed to keep the
pressure constant at an adjusted set point, es-
pecially in cryogenic plants.
The regulator consists of a valve with three
ports A, B and C, a spring-loaded operating
diaphragm (3) with set point adjuster (6) and
a pressure build-up plug (2).
Pressure build-up regulator
The process medium flows from port A to
port B. The valve is open when no pressure is
applied. The pressure downstream of the
valve is transmitted to the operating dia-
phragm (3). The resulting positioning force
moves the pressure build-up plug (2) depend-
ing on the spring force adjustable on the set
point adjuster (6). The valve is closed when
the pressure downstream of the valve has
reached the adjusted set point.
Pressure build-up regulator with safety func-
tion
The regulator additionally functions as a
safety valve for the pressure chamber up-
stream of port A. When the pressure exceeds
the set point by approx. 5 bar, the positioning
force overcomes the force of the closing
spring (4), causing the pressure build-up
plug (2) to open and the pressure to be re-
lieved to ports B and C.
Pressure relieve valve
The process medium flows from port B to
port C. As long as there is no pressure drop
across ports B and C, the plug seals off to-
wards the operating diaphragm (3).
The pressure at port B acts on the operating
diaphragm (3). The resulting positioning
force opposes the force of the set point
spring(s) (5) and opens the tubular plug (2.1)
when the adjusted set point is exceeded by
approx. 5 bar to equalize the pressures. The
medium escapes through the inside of the
plug through port C.
Optionally, the regulator can be equipped
with a non-return unit (10). The unit prevents
the medium from flowing back to port C and
allows maintenance work to be performed on
the pressure build-up regulator without hav-
ing to drain the tank.
To connect the regulator to the pipelines con-
taining the process medium, soldering nip-
ples with ball-type bushings (11) are avail-
able as accessories. Filters (12) for installa-
tion in ports A and B to prevent the valve from
clogging are also available as accessories.
1.1 Process medium, application
range
The pressure regulator is designed for cryo-
genic gases and liquids at temperatures from
–196 to +200 °C and pressures up to 40 bar.
Set points range from 1to 40 bar.
4EB 2558 EN
Design and principle of operation

EB 2558 EN 5
Design and principle of operation
Fig. 1 · Functional diagram of Type 2357-31
Type 2357-31
1 Valve body
2 Pressure build-up plug
2.1 Tubular plug
3 Operating diaphragm
4 Closing spring
5 Set point spring(s)
6 Set point adjuster, Allen key (width across flats SW 6)
6.1 Lock nut (width across flats SW 17)
7 Lower body section
10 Non-return unit (accessories)
11 Soldering nipple with ball-type bushing (accessories)
12 Filter (accessories)

2 Installation
Also see Fig. 1 on page 5.
The regulator is delivered free of oil and
grease for oxygen applications.
CAUTION!
Make sure the regulator is absolutely clean
and free of oil and grease for oxygen service.
Choose a place of installation that allows you
to freely access the regulator even after the
entire plant has been completed.
NOTICE!
Make sure the regulator is installed free of
stress. If necessary, support the piping near
the connecting flanges. Never attach supports
directly to the regulator.
2.1 Mounting position
Install the regulator with its main
axis in vertical position. The
lower body section (7) must point
down, port C must face up.
The direction of flow determines
the regulator's function:
–Pressure build-up regulator with safety
function: from port Ato B
–Pressure relief valve with non-return unit
from Bto C, port Cfaces up
NOTICE!
Impurities in the connecting lines can impair
the regulator's proper functioning, above all
the tight shut-off. As a result, make sure the
connecting lines are free of particles.
2.2 Shut-off valves, pressure
gauges
We recommend to install a hand-operated
shut-off valve both upstream and downstream
of the regulator to be able to shut down the
plant for cleaning and maintenance, and
when the plant is not used for longer periods
of time.
To monitor the pressures in the plant, install
pressure gauges in the appropriate locations.
6EB 2558 EN
Installation
Fig. 2 · Sample installation
C
AB
Type 2357-31
Pressure gauge

3 Operation
Also see Fig. 1 on page 5.
3.1 Start-up
CAUTION!
Do not start up the regulator before all com-
ponents have been installed in the plant.
NOTICE!
When pressure-testing the pipelines with the
regulator installed, the maximum permissible
regulator pressure must not be exceeded. This
pressure equals the maximum value of the set
point range.
3.2 Set point adjustment
By default, the pressure regula-
tor is adjusted to the set points
listed in Table 1. Nevertheless,
the set point can be changed by
turning the set point adjuster
with an Allen key with width
across flats SW 6.
–Clockwise turning P:
increases the pressure set point
–Counterclockwise turning Q:
decreases the pressure set point
If pressure gauges are installed in the con-
necting lines, the desired set point can be ad-
justed directly using the indicated pressure
gauge value. Without pressure gauges, the
set point is adjusted as shown in the adjust-
ment diagram in Fig. 3.
1. Loosen the lock nut (6.1) using the SW 17
wrench so far that the set point ad-
juster (6) can be moved freely.
2. Determine the difference between the
preset and the desired set point and turn
the set point adjuster clockwise or coun-
terclockwise for the required number of
turns (see Fig. 3). Any later change of the
default set point can also be done by de-
termining the required number of turns
according to Table 1.
3. Tighten the lock nut (6.1) to secure the
adjusted setting.
EB 2558 EN 7
Operation
Fig. 3 · Adjustment diagram
Turns of the set point adjuster
PSet point increase QSet point decrease
Set point in bar
Set point ad-
juster (6) with
lock nut (6.1)

3.3 Decommissioning
We recommend to close the shut-off valve up-
stream of the regulator, then the one down-
stream of the regulator.
4 Maintenance
The regulator is maintenance free. Neverthe-
less, it is subject to natural wear, particularly
at the seat, plug and operating diaphragm.
Depending on the operating conditions, the
regulator needs to be checked at regular in-
tervals to detect and avoid possible malfunc-
tions.
CAUTION!
Make sure the relevant plant section has been
depressurized and, depending on the pro-
cess medium, drained as well before remov-
ing the regulator from the pipeline.
Check the filters installed in ports A and B (if
applicable) and clean them if necessary.
If you do not succeed in removing faults or
malfunctions yourself, contact SAMSON for
support (see section 5).
8EB 2558 EN
Maintenance
Table 1 · Set point adjustment (default settings)
Set point range 1 to 8 bar 5 to 25 bar 8 to 40 bar
Set point adjusted to approx. 3 bar 12 bar 25 bar
Set point change
per turn of the adjuster 1 bar 2.5 bar 3.5 bar

5 Customer service
If malfunctions or defects occur, contact the SAMSON After-sales Service for support.
The addresses of SAMSON AG, its subsidiaries, representatives and service facilities world-
wide can be found on the Internet at www.samson.de, in a SAMSON product catalog or on the
back of these mounting and operating instructions.
Include the following details when making inquiries (see section 6):
4Regulator type
4Set point range, manufacturing data
4Customer-specific data (if mentioned on the spring housing or nameplate)
4Upstream and downstream pressures
4Temperature and process medium
4Min. and max. flow rate in m³/h
4Installation drawing
EB 2558 EN 9
Customer service

6 Nameplate
7 Technical data
10 EB 2558 EN
Nameplate · Technical data
Table 2 · Technical data · All pressures in bar (gauge)
Type 2357-31 Use with liquid process media
Nominal pressure PN 50
KVS coefficient 0.8 for pressure build-up · 0.2 for pressure relief
Set point range 1 to 8 bar · 5 to 25 bar · 8 to 40 bar
Permissible operating pressure 40 bar
Safety function 5 bar above the set point
Pressure relief function Approx. 1 bar above the set point
Temperature range –196 to +200 °C
Approx. weight 3.5 kg
Ports
A, B M40 x2
CM26 x1.5 male thread
Non-return unit M26 x1.5 or M40 x2
Fig. 4 · Specifications on the nameplate
1
2
3
Explanation
Specifications on the spring housing:
1 Set point range, manufacturing data
2 Type designation
3 Customer-specific data