Emerson VS-FL Series User manual

Type VS-FL
Instruction Manual
0017EN-VSFL-IM
January 2010 - Rev. 03
D103654X012
TM
SUMMARY
Introduction ........................................................................ 1
P.E.D. Categories and Fluid Group ................................... 2
Characteristics ................................................................... 2
Labelling ............................................................................ 2
Overpressure Protection .................................................... 3
Transport and Handling ..................................................... 3
Atex Requirements ............................................................ 3
Pilots .................................................................................. 4
Operation ........................................................................... 4
Dimensions and Weights ................................................... 5
Installation ......................................................................... 5
Startup ............................................................................... 6
Pilot Adjustment ................................................................. 6
Shutdown ........................................................................... 7
Periodical Checks .............................................................. 7
Relief Valve Maintenance .................................................. 7
Type PRX/182 Pilot Maintenance ...................................... 8
Spare Parts ........................................................................ 9
Troubleshooting ................................................................. 9
Parts Lists .......................................................................... 10
Schematic Assemblies ....................................................... 11
INTRODUCTION
Scope of Manual
This manual provides instructions for installation, startup,
maintenance and spare parts ordering for the VS-FL Series
pilot operated relief valves and for PRX/182 pilot.
Product Description
The VS-FL Series relief valves are axial ow type with a
single seat and counterbalanced shutter.
They are used in reduction, distribution and conveying
stations using suitably ltered natural gas.
They can also be used for air, propane, butane, LPG, city
gas, nitrogen, carbon dioxide and hydrogen.
The following versions are available:
VS-FL-BP: For low and mid pressure applications
Pilot PRX/182
VS-FL : For mid and high pressure applications
Pilot PRX/182 or PRX-AP/182
Also available version with type SR silencer.
All standard gas pressure devices (relief valves) used
in assemblies will comply to EN 12186 and EN 12279
standards.
Any accessories (e.g. pilots) used on the Emerson Process
Management range of relief valves, must be manufactured
by one of the Emerson Process Management companies
and bear that manual.
If this is not respected, Emerson Process Management will
not be responsible in the case of any inefciency.
Pilot-Operated Relief Valves
Figure 1. Relief Valve Type VS-FL with PRX/182 Pilot

Type VS-FL
2
P.E.D. CATEGORIES AND FLUID GROUP
The VS-FL/ Pilot-Operated Series relief valves are designed
as functional equipments and they are typically used in gas
pressure reducing stations for overpressure protection by
releasing small amounts of gas in the event of not perfect
pressure relief valve closing.
Table 1. P.E.D. Category for VS-FL Series Relief Valves
PRODUCT SIZE CATEGORY FLUID GROUP
DN 25 - 40 - 50 - 65 - 80 - 100 - 150 - 200 IV 1
If VS-FL/ series relief valve is used as full-capacity relief
device (according clause 8.3.2 EN 12186) , downstream
equipments protected by this products shall have technical
features such as not to be category higher than following
category (according Directive 97/23/EC “PED”).
Possible built-in pressure accessories (e.g. pilots PRX/
series or lters SA/2, FU/ and FD-GPL/) conform to Pressure
Equipment Directive (PED) 97/23/EC Article 3 section 3 and
were designed and manufactured in accordance with sound
engineering practice (SEP).
Per Article 3 section 3, these “SEP” products must not bear
the CE marking.
CHARACTERISTICS
Body Sizes and End Connection Styles
VS-FL-BP
DN 25 - 40 - 50 - 65 - 80 - 100 - 150
PN 16
ANSI 150 anged
VS-FL
DN 25 - 40 - 50 - 65 - 80 - 100 - 150 - 200
ANSI 300 - 600 anged
The pressure/temperature limits indicated
in this instruction manual or any applicable
standard or code limitation should not be
exceeded.
Maximum Operating Inlet Pressure
PN 16 : 16 bar
ANSI 150: 20 bar
ANSI 300: 50 bar
ANSI 600: 100 bar
At average ambient temperature.
Outlet Set Pressure Ranges
VS-FL-BP PN 16 ANSI 150 DN 25-40-50: 0.5 ÷ 8 bar
VS-FL-BP PN 16 DN 65-80-100-150 : 0.5 ÷ 16 bar
VS-FL-BP ANSI 150 DN 65-80-100-150 : 0.5 ÷ 19.3 bar
VS-FL ANSI 300 all sizes : 1 ÷ 50 bar
VS-FL ANSI 600 all sizes : 1 ÷ 80 bar
Minimum/Maximum Allowable Temperature (TS)
See label.
Temperature
Standard Version : Working -10° to 60°C
Low Temperature Version: Working -20° to 60°C
Materials
Flanges and covers: Steel
Diaphragms : Fabric Nitrile (NBR) + PVC
Nitrile (NBR) rubber
Pads : Nitrile (NBR) rubber
(FKM available on request)
LABELLING
Figure 2. Label for VS-FL Series Relief Valves
APPARECCHIOTIPO/DEVICE TYPE
Wau
DN2
DN1
MATRICOLA
bar
bar
SERIAL Nr.
°C
FLUIDO GRUPPO
FLUID GROUP
ANNO
YEAR
HARMONIZED STD.
bar
NORME ARMONIZ.
LEAKAGE CLASS
CLASSE DI PERDITA
FUNCTIONAL CLASS
CLASSE FUNZIONALE bar
Wao
Wa
TS
bar
pao
Cg
PS
body bar PT= xPS bar
PS
covers
EN
bar
pmax
xxxx
body
Notified
BOLOGNA ITALY
O.M.T.
1.5Nota4Nota3
Nota2
Nota1
1
-
!
WARNING

Type VS-FL
3
Note 1: See “Characteristics”
Note 2: Year of manufacture
Note 3: Class 1: -10°/60°C
Class 2: -20°/60°C
Note 4: PN 16 PS : 16 bar
ANSI 150 PS : 19.3 bar
ANSI 300 PS : 50 bar
ANSI 600 PS : 100 bar
OVERPRESSURE PROTECTION
The recommended safety pressure limitations are stamped
on the valve label.
Downstream overpressure protection shall be also provided
if the inlet pressure can be greater than the PS (see label).
Equipment’s operation below the maximum pressure
limitations does not preclude the possibility of damage from
external sources or debris in the line.
The relief valve should be inspected for damage after any
overpressure condition.
TRANSPORT AND HANDLING
Established transport and handling procedures shall be
followed to avoid any damage on the pressure containing
parts by shocks or anomalous stresses.
Ringbolts are designed just for handling of equipment
weight.
Built-up sensing lines and pressure accessories (e.g. pilots)
shall to be protected by shocks or anomalous stresses.
ATEX REQUIREMENTS
If the provisions of EN 12186 & EN 12279, national
regulations, if any, and specic manufacturer
recommendations are not put into practice before
installation and if purge by inert gas is not carried out before
equipment’s start-up and shut-down operations, a potential
external and internal explosive atmosphere can be present
in equipment & gas pressure regulating/measuring stations/
installations.
If a presence of foreign material in the pipelines is foreseen
and purge by inert gas is not carried out, the following
procedure is recommended to avoid any possible external
ignition source inside the equipment due to mechanical
generated sparks:
• drainage to safe area via drain lines of foreign materials, if
any, by inow of fuel gas with low velocity in the pipe-work
(5m/sec)
In any case,
• provisions of Directive 1999/92/EC and 89/655/EC shall
be enforced by gas pressure regulating/measuring station/
installation’s end user
• with a view to preventing and providing protection against
explosions, technical and/or organizational measures
appropriate to the nature of the operation shall be taken
(e.g. : lling/exhausting of fuel gas of internal volume
of the isolated part/entire installation with vent lines
to safe area - 7.5.2 of EN 12186 & 7.4 of EN 12279 ;
monitoring of settings with further exhaust of fuel gas to
safe area ; connection of isolated part/entire installation to
downstream pipeline; ….)
• provision in 9.3 of EN 12186 & 12279 shall be enforced
by pressure regulating/measuring station/installation’s end
user
• external tightness test shall be carried out after each
reassembly at installation site using testing pressure in
accordance with national rules
• periodical check/maintenance for surveillance shall be
carried out complying with national regulations, if any, and
specic manufacturer recommendations.

Type VS-FL
4
Table 2. Pilots Type PRX/182 and PRX-AP/182 Characteristics
Model Allowable Pressure
PS (bar)
Set Range
Wd (bar)
Body and Covers
Material
PRX/182
100
0.5 - 40
Steel
PRX-AP/182 30 - 80
N.B.: 1/4” NPT female threaded connections
PILOTS
VS-FL relief valves are equipped with the PRX/ series pilots.
Figure 3. Closed VS-FL Relief Valve Figure 4. Opened VS-FL Relief Valve
OPERATION
The diaphragm unit (permanently connected to the shutter) divides the relief valve actuator into two chambers.
The chamber 1 is connected to the atmospheric pressure, chamber 2 is connected to the pilot.
In normal working conditions the two chambers are not containing pressure and the relief valve spring acts on the diaphragm unit
and closes the shutter.
If the line pressure exceeds the pilot set point, the pilot allows the gas to ow from the line to chamber 2.
The shutter moves to its open position when the force produced by gas pressure acting on the diaphragm unit becomes greater
than the load of the relief valve spring.
Once the excess gas is released and line pressure returns to normal working conditions, the pilot stops the pressure ow,
Chamber 2 is no longer being fed, it is emptied through the jet.
The diaphragm unit is pushed upward by the relief valve spring and the shutter moves to its closed position.
Pilot
PRX/182
Jet
A
BL
A
BL
Chamber 1 Chamber 1
Diaphragm unit
Relief valve spring
Chamber 2
Shutter
Pilot
PRX/182
Jet
Diaphragm unit
Relief valve spring
Chamber 2
Shutter

Type VS-FL
5
Figure 5. VS-FL Series Dimensions
Table 3. VS-FL Series Dimensions
DIMENSIONS AND WEIGHTS
DN
DIMENSIONS (mm) WEIGHTS (Kg)
FACE TO FACE - I A
PN 16 - ANSI 150 ANSI 300 - ANSI 600 PN 16 - ANSI 150 ANSI 300 - ANSI 600 PN 16 - ANSI 150 ANSI 300 - ANSI 600
VS-FL-BP VS-FL VS-FL-BP VS-FL VS-FL-BP VS-FL
25 184 210 285 225 24 31
40 222 251 306 265 37 47
50 254 286 335 287 48 60
65 276 311 370 355 68 88
80 298 337 400 400 83 148
100 352 394 450 480 105 201
150 451 508 590 610 255 480
200* - 610 - 653 - 620
A
I
N.B.: (*) ANSI 300 I = 568 - 1/4” NPT female threaded connections
INSTALLATION
Figure 6. VS-FL Series Connection/Installation Schematic
NOTE: RECOMMENDED PIPING IS STAINLESS STEEL WITH 10 MM DIAMETER.
Jet
(0,75 mm)
A
B
L
PRX/182
VS/FL
Plug
To the atmosphere or in a safe area
To the atmosphere
or in a safe area

Type VS-FL
6
INSTALLATION (CONTINUED)
• Ensure that the data found on the valve label are
compatible with usage requirements.
• Ensure that the valve is mounted in accordance with the
direction of ow indicated by the arrow.
• Make the connections as indicated in gure 6.
!
WARNING
Only qualied personnel should install or
service a relief valve.
Relief valves should be installed, operated,
and maintained in accordance with interna-
tional and applicable codes and regulations.
Failure to take the relief valve out of service
immediately may create a hazardous
condition.
Personal injury, equipment damage, or
leakage due to escaping uid or bursting of
pressure-containing parts may result if this
relief valve is over-pressured or is installed
where service conditions could exceed the
limits given in the Specications section, or
where conditions exceed any ratings of the
adjacent piping or piping connections.
To avoid such injury or damage, provide
pressure-limiting devices (as required by the
appropriate code, regulation, or standard) to
prevent service conditions from exceeding
limits.
Additionally, physical damage to the relief
valve could result in personal injury and
property damage due to escaping uid.
To avoid such injury and damage, install the
relief valve in a safe location.
Before installation, check shall be done if
service conditions are consistent with use
limitations.
All means for draining must be provided in
the equipment installed before relief valves
(ENs 12186 & 12279).
If using a VS-FL/ series relief valve on
hazardous or ammable gas service,
personal injury and property damage could
occur due to re or explosion of vented gas
that may have accumulated.
To prevent such injury or damage, provide
piping or tubing to vent the gas to a safe,
well-ventilated area in accordance also
with international and applicable codes and
regulations.
In particular, when venting a hazardous gas,
the piping or tubing should be located far
enough away from any buildings or windows
so to not create a further hazard, and the
vent opening should be protected against
anything that could clog it.
If installing the relief valve at an outside loca-
tion, adequate protection, such as rain caps
or elbow piping, must be attached to the
outlet to keep the relief valve from getting
plugged or from collecting moisture, corro-
sive chemicals, or other foreign materials.
For outdoor installations, the relief valve
should be located away from vehicular trafc.
Further the ENs 12186 & 12279, where this product is used:
• provide the cathodic protection and electrical isolation to
avoid any corrosion and
• in accordance with clause 7.3/7.2 of aforesaid
standards, the gas shall be cleaned by proper lters/
separators/scrubbers to avoid any technical &
reasonable hazard of erosion or abrasion for pressure
containing parts
Pressure equipment in subject shall be installed in non-
seismic area and hasn’t to undergo re and thunderbolt action.
Clean out all pipelines before installation of the relief valve
and check to be sure it has not been damaged or has
collected foreign material during shipping.
For anged bodies, use suitable line gaskets and approved pip-
ing and bolting practices. Install the relief valve in any position
desired, unless otherwise specied, but be sure ow through
the body is in the direction indicated by the arrow on the body.
Installation must to be done avoiding anomalous stresses on
the body and using suitable joint means (bolts, anges, …)
according equipment dimensions and service conditions.
Note: It is important that the relief valve and relief valve be
installed so that the pilots vent holes are unobstructed at all
times.
For outdoor installations, the relief valve should be located
away from vehicular trafc and positioned so that water, ice,
and other foreign materials cannot enter through the valve pilot.
Avoid placing the equipment beneath eaves or downspouts,
and be sure it is above the probable snow level.
START-UP
The relief valve’s pilot is factory set at approximately the
midpoint of the spring range or at the pressure requested,
so an initial adjustment may be required to give the desired
results.
With proper installation completed and relief valves properly
adjusted, slowly open the upstream and downstream line
valves.

Type VS-FL
7
PILOT ADJUSTMENT
Mount upstream of the relief valve a unit capable of
generating the pressure at which the valve is to release gas
(a pressure regulator, a compressed air or gas cylinder or
the like) and a pressure gauge with appropriate scale.
Adjust the load of spring by means of adjusting screw
proceeding as follows:
• Fully tighten adjusting screw.
• Bring pressure upstream of relief valve up to set point.
• Slowly loosen adjusting screw until relief valve opens.
This is revealed by the escape of gas through vent.
• Decrease and subsequently increase pressure a few
times to check for proper valve operation and make any
adjustment in setting, if necessary.
SHUTDOWN
!
WARNING
To avoid personal injury resulting from
sudden release of pressure, isolate the relief
valve from all pressure before attempting
disassembly and release trapped pressure
from the equipment and pressure line.
In case of disassembly of main pressure re-
taining parts for checks and maintenance pro-
cedures, external and internal tightness tests
have to be done according applicable codes.
PERIODICAL CHECKS
CAUTION
It is recommended that relief valve and pilot
are checked periodically.
In order to check the efciency of the relief valve, line
pressure increase must be simulated using the same
procedure as described in previous “Pilot Adjustment”
paragraph.
Valve is in proper working order if gas release is noticed
upon pressure increase. Gas release must cease
immediately as pressure is brought back to its normal
working value.
It is also recommended that both pilot’s and relief valve’s
seal pads are checked periodically as described in the
following paragraphs.
RELIEF VALVE MAINTENANCE
(SEE FIGURES 7 TO 11)
!
WARNING
All maintenance procedures must be carried
out only by qualied personnel.
If necessary, contact our technical support
representatives or our authorized dealers.
VS-FL Series Relief valve and its pressure accessories are
subject to normal wear and must be inspected periodically
and replaced as necessary.
The frequency of inspection/checks and replacement
depends upon the severity of service conditions and upon
applicable National or Industry codes, standards and
regulations/recommendations.
In accordance with applicable National or Industry codes,
standards and regulations/recommendations, all hazards
covered by specic tests after nal assembling before
applying the CE marking, shall be covered also after every
subsequent reassembly at installation site, in order to ensure
that the equipment will be safe throughout its intended life.
Before proceeding with any maintenance work, shutoff the
gas upstream and downstream from the valve, also ensure
that there is no gas under pressure inside the body by
loosening the upstream and downstream connections.
Replacing Seal Pad
a. Disconnect all ttings preventing removal of outlet stub
pipe and take the latter off.
b. Loosen screws (key 5) and slide out outlet ange
(key 22), replace O-ring (key 18).
c. Remove pad holder (key 19) from the outlet cover
(key 13). Only for the DN 200 size the pad holder remain
attached to the outlet ange and it is not necessary
dismount it.
d. Loosen screw (key 25), pad retainer (key 21), remove and
replace pad unit (key 20).
e. Check that the part of sleeve (key 16) that touches
pad unit (key 20) is intact. If not, carry out general
maintenance and replace sleeve.
f. Reassemble by reversing the above sequence, being
careful not to damage O-ring (key 18). To facilitate tting
of pad holder (key 19), use an air pump that, when
connected to tting (key 17), causes sleeve (key 16) to
open fully.

Type VS-FL
8
Relief Valve General Maintenance
a. Disconnect all ttings, remove regulator from the line and
place it in upward vertical position.
b. Mark the position of inlet and outlet anges (key 1 and 22)
and cover (key 11 and 13) to keep the correct alignment
during the following reassembly phase.
c. Separate covers (key 11 and 13) by removing screws
(key 9).
!
WARNING
Spring (key 6) is compressed between
covers (key 11 and 13); its sudden release
could cause them to y apart dangerously.
To prevent this, replace the two screws
(key 9) with threaded rods and their nuts,
remove the remaining screws and use nuts
to slowly release spring tension.
d. Slide sleeve-diaphragm assembly (key 16 and 10) out of
inlet cover (key 11) and remove indicator (key 34).
e. Loosen screws (key 27), axially slide out of sleeve
(key 16) plates (key 8 and 12) and diaphragm (key 10).
Replace O-rings (key 26 and 28).
f. Loosen screws (key 5 or 64 for DN 150 and DN 200
sizes) and dismount inlet ange (key 1). Replace anti-
friction rings (key 2) and O-ring (key 3).
g. Unscrew travel indicator support (key 36) from inlet cover
(key 11), dismount parts, replace O-rings (key 35 and 37)
and O-ring (key 4) on the inlet cover (key 11).
h. Loosen screws (key 5) and axially slide out outlet ange
(key 22). Replace O-ring (key 18), anti-friction rings
(key 2) and O-ring (key 3).
i. Remove pad holder (key 19) from the outlet cover
(key 13). Only for the DN 200 size the pad holder remain
attached to the outlet ange and it is not necessary
dismount it.
j. Loosen screw (key 25), pad retainer (key 21), remove and
replace pad unit (key 20).
k. Check that the part of sleeve (key 16) that touches pad
unit (key 20) is intact. If not replace sleeve.
l. Check all moving parts, paying special attention to nickel
plated surfaces. Replace any that are worn or damaged.
m.Clean all stripped-down parts with petrol and dry with
compressed air.
Reassembly
Lubricate all seals with MOLYKOTE 55 M, being very careful
not to damage them when reassembling. Reassemble the
parts by reversing the above steps.
As you proceed, make sure that parts move freely and
without friction.
In addition:
a. Before tting sleeve-diaphragm assembly (key 16 and
10), recompose indicator group (key 34, 35, 36, 37, 38
and 40) and mount it on inlet cover (key 11).
Attach spring collet (key 33) to plate (key 8) upon
completion of reassembly. Don’t execute this assembly
for the DN 200 size.
b. Complete reassembly and make sure to tighten all screws
uniformly.
c. Remove cap (key 40) and tap with a rubber or wooden
hammer indicator (key 34) so as to couple spring collet
(key 33) and plate (key 8).
Only for DN 200 size insert indicator (key 34) and hook it
to plate (key 8), recompose indicator group (key 35, 36,
37, 38 and 40) and mount it on inlet cover (key 11).
d. Use an air pump connected to tting (key 7) to check
proper regulator working order.
e. After the reassembly completion, check the proper
functioning of all parts. Check the regulator with soapy
water, making sure there are no leaks.
f. Remount regulator on the line and reestablish all
connections.
TYPE PRX/182 PILOT MAINTENANCE
(SEE FIGURE 12)
Installation
a. Make sure that specications on the pilot plate comply
with the intended use.
b. Make sure that all connections are correctly made.
Startup
Refer to the relief valve startup instructions.
Periodical Checks
Pilot tightness should be tested regularly by referring to the
following procedure:
a. Supply tting A with normal operating pressure.
b. Make sure there is no gas outow from tting B.

Type VS-FL
9
Maintenance
CAUTION
Maintenance should be carried out by skilled
personnel to ensure good servicing results.
Contact our technical support representatives
or our authorized dealers for any information.
Let gas under pressure ow out of the
relevant part of the system before servicing.
General Maintenance
a. Disconnect and remove the pilot from the line.
b. Fully unscrew the adjusting screw (key 1).
c. Unscrew the cap (key 3), for the AP version also the
extension (key 35), remove the spring holder (key 6) and
the spring (key 7). Replace the O-rings (key 4 and 5).
d. Loosen screws (key 10), remove the upper cover (key 8)
and the lower cover (key 21). Replace the O-ring (key 18).
e. Lock the stem (key 23) by inserting a key into the notches
and unscrew nuts (key 20 and 26).
f. Disassemble the parts and replace the diaphragm
(key 14) and the pad (key 22).
g. Unscrew the seat (key 19) and replace the O-ring (key 17).
h. Use petrol to cleanse the pilot body and all metal parts. Blow
them thoroughly with compressed air and check for clear
holes along the gas conduits. Replace any worn parts.
Reassembly
Reassemble all parts by following in reverse order the
assembly as described above (see General Maintenance
section).
As parts are assembled, make sure they move freely
causing no friction.
Make sure to:
a. O-rings and diaphragms should be lubricated by applying
a thin layer of ‘Molykote 55 M’ grease.
Pay attention not to damage them during reassembly. All
other pilot parts require no lubrication.
b. The cover clamping screws (key 10) should be tightened
evenly to ensure proper tightness.
c. Pilot operation, calibration and tightness should be tested
as described in the Periodical Checks paragraph.
d. Previously disassembled ttings must be connected.
Check for leaks by using suds.
Calibration
See the paragraph Pilot Adjustment on page 6.
SPARE PARTS
Spare parts storage shall be done by proper procedures
according to national standard/rules to avoid over aging or
any damage.
TROUBLESHOOTING
Table 4. General Troubleshooting for VS-FL Series Relief Valves
SYMPTOMS CAUSE ACTIONS
The valve does not open
Lack of incoming gas Check the station feeding
Pilot is not being supplied Check pilot connections
Valve diaphragm is broken To be replaced
Pilot setting is higher than required Check pilot setting
The valve is not sealed properly
Tight shutoff gaskets are worn To be replaced
Deposits of grime on the tight shutoff pad are
obstructing proper positioning of the shutter Clean or replace it
Pilot setting is lower than required Check pilot setting

Type VS-FL
10
PARTS LISTS
VS-FL Relief Valve
(See Figures 7 to 11)
Key Description
1 Inlet ange
2* Anti-friction ring
3* O-ring
4* O-ring
5 Screw
6 Spring
7 Fitting
8 Inlet plate
9 Screw
10 Diaphragm
11 Inlet Cover
12 Outlet plate
13 Outlet cover
14 Washer
15 Nut
16 Sleeve
17 Fitting
18* O-ring
19 Pad holder
20* Pad unit
21 Pad retainer
22 Outlet ange
25 Screw
26* O-ring
27 Screw
28* O-ring
29 Label support
30 Label
31 Rivet
32 Label
33 Spring collet
34 Indicator
35* O-ring
36 Support
37* O-ring
38 Bush
39 Indicator label
40 Cap
43 SR silencer
46* O-ring
47* O-ring
48 Washer
59 Eyebolt
61 Special screw
62 Screw
63 Elastic washer
64 Screw
64 Screw
65 Elastic pin
400 Plate
401 Bush
Key Description
402* O-ring
403 Support
404* O-ring
405 Spring collet
406 Indicator
407 Nut
408 Bracket
409 Support
410 Proximity switch
411 Fitting
Type PRX/182 Pilot
(See Figure 12)
Key Description
1 Adjusting screw
2 Nut
3 Cap
4* O-ring
5* O-ring
6 Spring carrier plate
7 Spring
8 Upper cover
9 Spring carrier plate
10 Screw
11 Washer
12 Filter
13 Plate
14* Diaphragm
15 Plate
16 Body
17* O-ring
18* O-ring
19 Seat
20 Nut
21 Lower cover
22* Pad holder unit
23 Stem
24 Plate
25* O-ring
26 Nut
28* O-ring
29 Plate
31 Screw
33 Plug
34 Plug
35 Extension
Rubber parts marked with (*) are supplied in the “spare parts
kit”, recommended as stock.
To order the kit it is necessary to communicate to us the type
of the relief valve or pilot and its serial number.

Type VS-FL
11
18
16
22
13 14 15
4
10
3
2
3
2
2
2
12
1
7
22
3
178
6
11
5
9
5
26
27
28
31 30 2932313334353637383940
Figure 7. VS-FL Relief Valve DN 25 to DN 150
SCHEMATIC ASSEMBLIES
LM/1403

Type VS-FL
12
LM/1403
Figure 8. Pad Holder for VS-FL Relief Valve DN 25 to DN 150
19
19
20
21
47
20
25
PAD HOLDER
DN 25 TO DN 50
PAD HOLDER
DN 25 TO DN 50
PAD HOLDER
DN 65 TO DN 150
PAD HOLDER
DN 65 TO DN 150
19
20
21
19
20
21
C
43
46
48
25
47
46
48
25
43
21
25
SILENCED VS-FL
NOT SILENCED VS-FL

Type VS-FL
13
1
2
2
3
2468910 11 12 13 14 15
16 18 2
35
219
20
21
47
26
27
28
31 30 29
31 32
33
34
35
36
3738
3940
25
22
65
62
63
59
3
2
64
59
Figure 9. VS-FL Relief Valve DN 200

Type VS-FL
14
LM/1403
Figure 10. VS-FL Relief Valve DN 150 Various Versions
Figure 11. VS-FL Relief Valve DN 25 to DN 150 with Proximity
LM/1403
5
VS-FL/150 ANSI 300-600 DETAIL
61
64
5
64
VS-FL/150 ANSI 300-600 DETAIL
VS-FL-BP/150 DETAIL
VS-FL-BP/150 DETAIL
59
VS-FL/ AND VS-FL-BP/ WITH PROXIMITY SWITCH VERSION
411
409
407
410
400
408 407 402 403
401
404 406 405

Type VS-FL
15
B
A
A
L
B
S
33
28 31 29
28
34
34
22
19
14
17
16
18
1413
1
2
3
4
5
6
7
8
9
10
11
12
13
15
11
20
10
11
21
22
23
24
18
11
26
25
35
4
4
LM/1390
Figure 12. Type PRX/182 and PRX-AP/182 Pilots
AP VERSION
A B L
To the controlled
pressure
To Chamber 2 of the
relief valve
To the controlled
pressure
PRX/182
SECTION A-A
Table 5. Type PRX/182 and PRX-AP/182 Connections

Type VS-FL
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