PIETRO FIORENTINI REFLUX 819 User manual

PRESSURE REGULATOR
REFLUX 819
TECHNICAL MANUAL MT050
INSTALLATION, COMMISSIONING AND MAINTENANCE INSTRUCTIONS
E

2
TECHNICAL MANUAL MT050
REFLUX 819
INLET PRESSURE OUTLET PRESSUREPILOT FEED
R14/A
204/A
Issue january 2021

3
TECHNICAL MANUAL MT050

4
TECHNICAL MANUAL MT050

TECHNICAL MANUAL MT050
5
GENERAL PRECAUTIONS
- The apparatus described in this manual is a device subject to pressure installed in systems under pressure;
- the apparatus in question is normally installed in systems for transporting flammable gases (natural gas, for
example).
PRECAUTIONS FOR THE OPERATORS
Before proceeding with installation, commissioning or maintenance, operators must:
- examine the safety provisions applicable to the installation in which they must work;
- obtain the authorisations necessary for working when so required;
- use the necessary means of individual protection (helmet, goggles, etc.);
- ensure that the area in which they operate is fitted with the means of collective protection envisaged and with
the necessary safety indications.
HANDLING
The handling of the apparatus and of its components must only be carried out after ensuring that the lifting gear
is adequate for the loads to lift (lifting capacity and functionality). The apparatus must be handled using the lifting
points provided on the apparatus itself.
Motorised means must only be used by the persons in charge of them.
PACKING
The packing for trasportation of equipment and of relevant spare parts are designed and shaped to avoid damage to any
part during transportation, warehousing and handling activities. Therefore the equipment and spare parts shall be kept
into their packing until their installation in the final site. After packing is open, check that no damage occured to any
goods. If damage occured inform the supplier and keep packing for any verification.
INSTALLATION
If the installation of the apparatus requires the application of compression fittings in the field, these must be
installed following the instructions of the manufacturer of the fittings themselves. The choice of the fitting must
be compatible with the use specified for the apparatus and with the specifications of the system when envisaged.
PRECAUTIONS

TECHNICAL MANUAL MT050
COMMISSIONING
When commissioning, the risks associated with any discharges into the atmosphere of flammable or noxious
gases must be assessed. In installations in natural gas distribution networks, the risk of the formation of explosive
mixtures (gas/air) inside the piping must be considered.
CONFORMITY TO DIRECTIVE 2014/68/EU
Pressure regulators series Reflux 819 are classified as fail close regulator according to the standard EN 334
therefore they are categorized as safety accessories acording to directive 2014/68/EU.
The incorporated safety device monitor PM/819 (as well as the in-line monitor REFLUX 819) being classified as
fail close regulators according to the standard EN 334 is categorized as safety accessory according PED, therefore
it can be used both as pressure accessory and safety accessory to PED.
The regulator Reflux 819 when incorporating slam-shut valve SB/82 or HB/97 with pressure switches for
overpressure is categorized as safety accessory according to PED, therefore it can be used bot as pressure
accessory and safety accessory to PED.
Conformity with Directive PED of pressure regulator and relevant accessory bearing the CE marking require
installation in the system with minimum requirements according to EN 12286.
6

7
TECHNICAL MANUAL MT050
1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PAGE 9
1.1 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 SETTING SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.0 INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.0 ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 RELIEF VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1.1 DIRECT INSTALLATION ON THE LINE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.1.2 INSTALLATION WITH ON/OFF VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2 ACCELERATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.0 MODULARITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1 INCORPORATED SLAM-SHUT VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2 INCORPORATED SB/82 SLAM-SHUT VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2.1 SB/82 SLAM-SHUT OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2.2 SB/82 SLAM-SHUT SETTING SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3 INCORPORATED HB/97 SLAM-SHUT VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3.1 HB/97 SLAM-SHUT OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.3.2 HB/97 SLAM-SHUT SETTING SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.4 MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.4.1 PM/819 INCORPORATED MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.4.2 IN-LINE MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.0 START UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.2 GAS INPUT, CONTROL OF EXTERNAL TIGHTNESS AND SETTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.3 COMISSIONING THE REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.4 COMMISSIONING THE REGULATOR WITH INCORPORATED SB/82 SLAM-SHUT . . . . . . . . . . . . . . . . . . . . . . 31
5.5 COMMISSIONING THE REGULATOR WITH INCORPORATED PM/819 MONITOR AND
ACCELERATING VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.6 COMMISSIONING THE REGULATOR PLUS REFLUX 819 IN-LINE MONITOR WITH INCORPORATED SB/82
SLAM-SHUT VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.0 TROUBLE-SHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.1 REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.2 SB/82 SLAM-SHUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
7.0 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
7.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
7.2 REFLUX 819 REGULATOR MAINTENANCE PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
7.3 PM/819 MONITOR MAINTENANCE PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
7.4 DB/819 SILENCER MAINTENANCE PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7.5 SB/82 SLAM-SHUT DEVICE MAINTENANCE PROCEDURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.0 FINAL OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
8.1 CONTROL OF TIGHTNESS AND SETTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
8.2 START UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.0 WEIGHT OF THE COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
9.1 WEIGTH OF THE COMPONENTS IN KG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
10.0 LIST OF RECOMMENDED SPARE PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
INDEX

8

TECHNICAL MANUAL MT050
This manual proposes to provide the essential information for the installation, start-up, disassembly, reassembly
and maintenance of the Reflux 819 regulators.
It is also appropriate, however, to provide a brief illustration of the main features of the regulator and of its
components.
1.1 MAIN FEATURES
The Reflux 819 pressure regulator is a regulator of the piloted type for medium and high pressures.
The Reflux 819 is a fail close type regulator and therefore closes in the event of:
- rupture of the main diaphragm;
- rupture of the pilot diaphragm/s;
- pilot circuit supply failure.
The main features of this regulator are:
- design pressure: up to 100 bar;
- design temperature: -20 °C to +60 °C;
- environmental temperature: -20 °C to +60 °C;
- range of the inlet pressure bpe: 0,5 to 85 bar;
- possible regulation range Wh: 0,3 to 74 bar (on the basis of the pilot installed);
- minimum differential pressure: 0.5 bar;
- precision class AC= up to 1;
- closing pressure class SG: up to 3.
1.2 OPERATION (FIG. 1)
In the absence of pressure, the obturator 5 is maintained in the closed position by the spring 54, and rests on the
reinforced gasket 7 (fig. 1). The upstream pressure, even if variable, does not change this position as the obtura-
tor is completely balanced and is therefore subject to equal pressures, even if the sections are different.
The rod 6 is also between two equal pressures as the pressure upstream is also conveyed to the chamber C throu-
gh the hole A.
The obturator is controlled by the diaphragm 50 on which the following forces act:
•downwards: the load of the spring 54, the thrust deriving from the regulated pressure Pa in the chamber D and
the weight of the mobile assembly;
•upwards: the thrust deriving from the motorisation pressure Pm in the chamber E, supplied by the pilot.
The motorisation pressure is obtained by drawing gas from gas the regulator at the upstream pressure. The gas
is filtered through the filter 13 and is subjected to initial decompression in the pre-regulator R14/A (fig. 2)
composed essentially of an obturator 5, a spring 12 and a diaphragm 10 to a value, Pep, which depends on the
pressure set-point of the regulator. The pressure, Pep, then passes from the chamber G through the hole F in the
204/A pilot which adjusts it by means of the obturator 17 until the inlet value, Pm, in the head of the regulator.
The regulation of Pm is obtained by the comparison of the force exerted by the setting spring 22 of the pilot and
the action of the regulated pressure, Pa, acting in the chamber B on the diaphragm 16.
9
1.0 INTRODUCTION

TECHNICAL MANUAL MT050
10
The set-point can be changed by turning the adjustment screw 10; clockwise rotation increases Pm and therefore
the regulated pressure, Pa; the opposite occurs when the ring is turned anticlockwise. If, for example, the
downstream pressure, Pa, drops during operation (because of an increase in the requested flow rate or a drop in
the upstream pressure) an imbalance occurs in the mobile assembly 15 of the pilot, which is displaced to increase
the opening of the obturator 17. As a result, the motorisation pressure value, Pm, increases and, by acting in the
chamber E under the diaphragm 50 (fig. 1), causes the obturator 5 to move upwards and therefore an increase in
the opening of the regulator until the set-point of the regulated pressure is restored.
Fig. 1
Connections to be made by the customer Ref. No. for the connections
3
1
13

TECHNICAL MANUAL MT050
11
Vice versa, when the regulated pressure begins to increase, the force it exerts on the diaphragm 16 of the pilot
moves the mobile assembly 15 displacing the obturator 17, towards the closed position. The pressure, Pm,
then drops because of the transfer between the chambers E and D through the orifice 21, and the force exerted
by the spring 54 causes the downward dis-
placement of the obturator 5, to restore the regulated pressure to the set-point. In normal working conditions,
the obturator 17 of the pilot positions itself so that the motorisation pressure value, Pm, is such as to maintain
the downstream pressure value, Pa, around the set-point.
Fig. 2
vent

TECHNICAL MANUAL MT050
12
1.3 SETTING SPRINGS
The Reflux 819 regulator uses the 204/A, 205/A, and 207/A pilots. The regulation range of the different pilots is
given in the tables below.
The operating principle of the pilot has already been briefly illustrated in par. 1.2. Variation of the setting is obtained
by turning the adjustment screw 10 (fig. 2). Clockwise rotation leads to an increase in the regulated pressure while
anticlockwise rotation leads to a decrease. When the desired setting has been reached, the adjustment screw can
be blocked by means of the provided nut 9.
De = Øexternal diameter d = Øwire diameter i = active coils Lo = Lenght it = total coils
Tab. 1 Pilot 204/A, 204/A/1
Code Colour De Lo d i it Setting range in bar
2701260 WHITE 3.5 7.5 7.5 0.3 ÷1.2
2701530 YELLOW 4 7 7 0.7 ÷2.8
2702070 ORANGE 5 7 7 1.5 ÷7
2702450 RED 35 60 6 7 7 4 ÷14
2702815 GREEN 7 7 7 8 ÷20
2703220 BLACK 8 6 6 15 ÷33
2703420 BLUE 8.5 6 6 22 ÷43
Tab. 2 Pilot 205/A
Code Colour De Lo d i it Setting range in bar
2702820 BLUE 7 7 9 20 ÷35
2703045 BROWN 35 100 7.5 7.5 9.5 30 ÷43
2703224 GREY 8 7.5 9.5 40 ÷60
Tab. 3 Pilot 207/A
Code Colour De Lo d i it Setting range in bar
2703224 GREY 35 100 8 7.5 9.5 41 ÷74

TECHNICAL MANUAL MT050
13
2.1 GENERAL
Pressure regulator does not require any supplementary upstream safety accessory for protection against
overpressure compared with its design pressure PS, when upstream reducing station is sized for a max
downstream incidental pressure MIPd ≤1,1 PS.
Before installing the regulator it is necessary to ensure that:
- the regulator can be inserted in the space provided and that subsequent maintenance operations will be
sufficiently practicable;
- the upstream and downstream piping is at the same level and capable of supporting the weight of the regulator;
- the inlet/outlet flanges of the piping are parallel;
- the inlet/outlet flanges of the regulator are clean and the regulator itself has not been subject to damage during
transport;
- the piping upstream has been cleaned to expel residual impurities such as welding scale, sand, paint residues,
water, etc.
The normally raccomended set-up is:
2.0 INSTALLATION
Fig. 3 (Standard regulator)

TECHNICAL MANUAL MT050
14
Regulator
Downstream connection
Sensing line Control pressure gauge
Bleed clock
On/Off valve
Regulator
Downstream connection
Sensing line
Control pressure
gauge
Bleed clock
On/Off valve
TAB. 4 CONNECTING THE APPARATUSES
The connections between the apparatus and the main piping must be made using stainless steel pipe with
minimum internal diameter of 8 mm.
IN-LINE INSTALLATION
INSTALLATION AT RIGHT ANGELS

TECHNICAL MANUAL MT050
15
1and 2Connect to regulators heads
3and 4Connect to pilots
5and 6Connect to accelerator and slam-shut
The regulator must be installed in the line with the arrow on the body pointing in the gas flow direction.
It is indispensable for good regulation that the position of the downstream pressure take-offs and the speed of the
gas at the take-off point respect the values given in tables 4 and 5 (positioning) and 6 (speed).
The pressure regulator, when installed on a reducing station, shall be installed at least according to the
requirements of standard EN 12186.
All venting connections shall be connected as required by above mentioned standard.
The following is recommended so as to prevent the accumulation of impurities and condensate in the lines
of the pressure take-offs:
a) the lines themselves must slope down towards the downstream piping connectors with a slope of about 5-10%;
b) the connectors on the piping must always be welded on the top of the piping itself and there must be no burr
or inward protrusions in the hole in the piping.
NB.WE RECOMMEND NOT TO PUT ON/OFF VALVES ON THE IMPULSE TAKE-OFFS
TAB. 5 DETAIL OF MULTIPLE TAKE - OFF WITH OF THE IMPULSE TAKE - OFF REFERENCE NUMBERS
TAB. 6
The speed of the gas must not exceed the following values in the piping downstream from the regulator:
Vmax= 30 m/s for Pa > 5 bar
Vmax= 25 m/s for 0,5 < Pa < 5 bar
3.0 ACCESSORIES
3.1 RELIEF VALVE
The relief valve is a safety device which releases a certain quantity of gas to the exterior when the pressure at the
control point exceeds the set-point as a result of short-lasting events such as, for example, the very fast closing
of the on/off valves and/or overheating of the gas with zero flow rate demand. The release of the gas to the exterior
can, for example, delay or block intervention of the slam-shut valve for transitory reasons deriving from damage
to the regulator.

TECHNICAL MANUAL MT050
16
Fig. 4
Obviously the quantity of gas released depends on the extent of the overpressure with respect to the set-point. The
different models of relief valve available are all based on the same operating principle which is illustrated below with
reference to the valve VS/AM 56 (fig. 4).
It is based on the contrast between the thrust on the diaphragm 24 deriving from the pressure of the gas to control
and the thrust from the setting spring 20. The weight of the mobile assembly, the static thrust and the residual
dynamic thrust on the obturator 4 also contribute to this contrast.
When the thrust deriving from the pressure of the gas exceeds that of the setting spring, the obturator 4 is raised
and a certain quantity of gas is released as a result.
As soon as the pressure drops below the set-point, the obturator returns to the closed position. Proceed as
indicated below to control and adjust intervention of the relief valve.
3.1.1 DIRECT INSTALLATION ON THE LINE (FIG. 5)
When the relief valve is fitted directly in the line without, that is, the interposition of an on-off valve, we recommend
proceeding as follows:
1)Ensure that the downstream on/off valve V2 and the bleed cock 6 are closed;
2)Increase the pressure in the downstream section to the value envisaged for intervention in one of the following
ways:
- if the spring fitted on the pilot permits it (see tebles 1-2 and 3) increase the setting of the pilot itself until the
desider value is obtained;
- connect a controlled auxiliary pressure to the cock 6 and stabilize it at the desidered value;
3)Check intervention of the relief valve and adjust it if necessary by turning the adjustment plug 13 appropriately
(clockwise to increase the set-point, anticlockwise to reduce it).
Fig. 5

TECHNICAL MANUAL MT050
17
3.1.2 INSTALLATION WITH ON/OFF VALVE (FIG. 6)
1) Close the on/off valve 16;
2)Connect a controlled auxiliary pressure to the take-off 17 and increase it slowly to the envisaged intervention
value;
3)Check the intervention of the relief valve and adjust it if necessary by turning the adjustment plug 13
appropriately (clockwise to increase the set-point, anticlockwise to reduce it).
3.2 ACCELERATOR
An accelerator (fig. 7) is installed on the PM/819 icorporated monitor and on the REFLUX 819 regulator (use as
in-line monitor) to speed up their intervention in the event of failure of the active regulator (racommended when
used safety accessory according to Directive 2014/68/EU).
On the basis of a pressure signal from downstream this device discharges the gas into the monitor's motorization
chamber into the atmosphere, thereby permitting rapid intervention. The set point of the accelerator must
obviously be higher than that of the monitor.
Setting is made by turning the adjustment screw 17, clockwise to increase the value, anticlockwise to reduce it.
M/A range of intervention Who: 0,3 to 43 bar
Fig. 7
Accelerator M/A
vent
vent
Fig. 6

TECHNICAL MANUAL MT050
18
4.0 MODULARITY
The modular-type design of RELUX 819 series regulators means that it is also possible to feitner the emergency
monitor regulator PM/819 or it the slam-shut incorporated with the body itself even after the installation of the
regulator without any modifications.
4.1 INCORPORATED SLAM-SHUT VALVE
When closing the slam shut incorporated into pressure regulator to be considered as safety accessory according
to Directive PED, cuts off the feeding of gas both to pressure regulator and to its pilot.
4.2 INCORPORATED SB/82 SLAM-SHUT VALVE
This is a device (fig. 8) which immediately blocks the gas flow if, following some kind of failure, the downstream
pressure reaches the set-point for its intervention, or is operated manually.
On the REFLUX 819 regulator, it is possible to have the SB/82 slam-shut incorporated both with the service regu-
lator and on the one functioning as in-line monitor.
The main characteristics of the slam-shut device are:
•intervention with pressure increase and/or decrease;
•design pressure: 100 bar for all the components;
•intervention accuracy (AG): ± 1% of the pressure set-point for pressure increases; ± 5% for pressure drops;
•manual resetting with internal by-pass operated by the resetting lever.
Fig. 8

TECHNICAL MANUAL MT050
19
4.2.1 SB/82 SLAM-SHUT OPERATION (FIG. 9)
The SB/82 slam-shut device (see fig. 9) consists of an obturator A, a releasing lever system, a control head B and
a resetting system which is controlled manually by the lever C. The pressure in the circuit to control acts on the
diaphragm in the control head B. This diaphragm, which is integral with a control rod D, receives a counter-force
by means of the minimum pressure springs 17 and the maximum pressure springs 11, set at the preset values .
The translation movement of this rod provokes the displacement of the lever L which controls the release of the
entire mobile system and frees the obturator which is closed by the action of the spring 48.
To reset the device, operate the lever C. This opens an internal by-pass in the first part of its stroke. This leads to
filling of the downstream zone and balances the pressure on the obturator. Then, complete resetting of the entire
mobile system is obtained in the second part of the stroke of the lever C. Releasing can also be carried out
manually by means of the button 101.
Fig. 9

TECHNICAL MANUAL MT050
20
CONTROL DEVICE
SLAM-SHUT CONTROL HEADS
Fig. 10
Fig. 11
MOD. 102 -106 MOD. 103 -106
MOD. 104 -107 MOD. 105-108 - 109
Mod. 102 - 103 - 104 - 105 Mod. 106 - 107 - 108 - 109