GW Sprinkler M5 User manual

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
1
GW Model M5
Low Pressure Water Mist Fire Protection
Local Application Fire Protection System for
Category A machinery spaces and other spaces
with similar high-risk applications.
GW Sprinkler A/S
Kastanievej 15 DK5620 Glamsbjerg - Denmark
Tel: [phone]
Fax: [phone]
e-mail: [email protected]

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
2
Table of Content:
1 The System & The Applications
1.1 Principle requirements for the system (MSC.1 / Circ.1387).
1.2 System operation.
1.3 Arrangement of nozzles and water supply.
1.4 System Components
1.5 Protection of applications in category A machinery spaces, and applications of similar risk in
other spaces.
1.6 System Performance
1.7 Low water pressure, low water flows, wide installation heights, low electric power
requirements
1.8 Fire hazards and fuels
1.9 Water as extinguishing agent.
1.10 Key System Components.
2 Nozzle Design and Installation Requirements
2.1 Nozzle design, and installation of nozzles.
2.2 Nozzle installation in machinery spaces.
2.3 Obstructions between applications and pendent installed nozzles.
2.4 Additional nozzles.
2.5 Horizontal installed nozzles.
2.5.1 Nozzles installed horizontally to spray in parallel with the application surfaces
2.5.2 Nozzles installed horizontally to spray direct on the application surfaces
3 System Design
3.1 Overall system design
3.1.1 Guidelines and recommendations
3.1.2 Activation times
3.1.3 Hydraulic calculated systems
3.1.4 Power supplies
3.1.5 Water Supplies
3.1.6 System activation
3.1.7 Design of pipe installation
3.1.8 System support
4 System Control Valve Unit
4.1 GW Control Units in general
4.1.1 Sizes and hydraulic connections
4.1.2 Sizes and friction losses
4.1.3 Components and materials
4.1.4 Electric connection
4.1.4.1 Monitoring system
4.1.4.2 Impulse Solenoid Valve
4.2 The performance of GW Control Unit
4.2.1 Control Unit in standby model
4.2.2 Activation of the local application system
4.2.3 Closing and returning the control unit back to standby model after activation
4.2.3.1 Control Unit activated on solenoid valve, or manual released valve
4.2.3.2 Control Unit activated from sprinkler detector
4.2.4 Pre-Action Activation Trim
4.3 Installation and Tests of Control Units
4.3.1 Installation position
4.3.2 Hydraulic installation
4.3.3 Electric installation
4.3.4 Installing & designing hydraulic activation system
4.3.5 Test of monitoring circuits
4.3.6 Functional tests of control unit
4.3.7 Spares which should be available on site

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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4.4 Maintenance and tests of Control Units
4.5 Checklist for faults
5 Hydraulic Activation System
5.1 By-Pass valve to avoid water access to dry nozzle pipes when setting system in standby
5.2 Acceptable friction loss for hydraulic activation system
5.3 Hydraulic manual activation
5.4 GW Manual Release Control Boxes
5.5 Hydraulic activation system pipes
5.6 Heat activated sprinkler detectors
5.7 Electrical methods of activation
5.7.1 Solenoid valve activation
5.7.2 Electric operated sprinkler heat detectors
6 Ordering System Components from GW Sprinkler A/S
6.1 Ordering GW Model M5 Water Mist Nozzles
6.2 Ordering GW Control Units
6.2.1 Ordering spare parts for Control Units
6.3 Ordering components for Hydraulic Activation Systems
6.3.1 Sprinkler detectors
6.3.2 Pre-Action Electrically released system
6.3.3 Control Boxes
6.4 Manual Activation Switches
Appendix & Figures
Figures: A1 Nozzle System
A2 Local Application System.
B1 Maximal obstruction seen from Nozzle
B2 Obstructions seen from the application surface, which require additional
nozzles
B3 & B4 Obstructed horizontal spray
C1 & C2 Nominal design parameters for horizontal spray.
D1 Water supply system w. pressure tank.
D2 Water supply system w. jockey pump.
E2 Control Unit
E3 Water Flow in Electric Activated Control Unit (Pre-action activation)
E4 Connections for switches on control unit.
E5 Water Flow in Control Unit. (Electric & Hydraulic)
F1, F2 Ordering Table
Data-sheets: 140209 Impulse solenoid valve
140178 Pressure Switch
140187 GW M5 - water mist nozzle
140158 GW PyroStop valves
14590 GW-DD1 QR heat detectors
14457 GW-DD1 QR-El / heat sprinkler detectors
140080 GW Control Boxes
14628 Heat Collector, Sprinkler Detector Guards etc.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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1. The system & the applications.
1.1 Principal requirements for the system
(as outlined in MSC.1/Circ.1387 Annex : Revised Guidelines for the approval of fixed
water based local application fire-fighting systems for use in category A machinery
spaces):
Fixed water-based local application fire-fighting systems should provide localized fire suppression in areas,
as specified in SOLAS regulation II-2/10.5, for category A machinery spaces, without the necessity of engine
shut-down, personnel evacuation, shutting down of forced ventilation fans, sealing of the space – or activities
that could lead to loss of electrical power and/or reduction of manoeuvrability.
1.2 System operation
.1 The system should be capable of manual release.
.2 The activation of the system should not require engine shutdown, closing fuel oil tank outlet
valves, evacuation of personnel or sealing of the space, which could lead to loss of electrical power
or reduction of maneouvrability. This is not intended to place requirements on the electrical
equipment in the protected area when the system is discharging freshwater.
.3 The operation controls should be located at easily accessible positions inside and outside the
protected space. The controls inside the space should not be liable to be cut off by a fire in the
protected areas.
.4 Pressure source components of the system should be located outside the protected areas.
.5 Where automatically operated fire-fighting systems are installed:
.1 a warning notice should be displayed outside each entry point stating the type of
medium used and the possibility of automatic release;
.2 the detection system should ensure rapid operation while consideration should
also be given to preventing accidental release. The area of coverage of the detection
system sections should correspond to the area of coverage of the extinguishing
system sections. The following arrangements are acceptable:
.1 set-up of two approved flame detectors; or
.2 set-up of one approved flame detector and one approved smoke
detector. Other arrangements can be accepted by the Administration.
However, use of heat detectors should in general be avoided for
these systems;
.3 the discharge of water should be controlled by the detection system. The detection
system should provide an alarm upon activation of any single detector and discharge
if two or more detectors activate. The Administration may accept other arrangements;
and
.4 visual and audible indication of the activated section should be provided in the
engine control room and the navigation bridge or continuously manned central control
station. Audible alarms may use a single tone.
.6 Operating instructions for the system should be displayed at each operating position.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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.7 Appropriate operational measures or interlocks should be provided if the engine-room is fitted
with a fixed high-expansion foam or aerosol fire-fighting system, to prevent the local application
system from interfering with the effectiveness of these systems.
1.3 Arrangement of nozzles and water supply
.1 The system should be capable of fire suppression based on testing conducted in accordance
with the appendix to these Guidelines. Any installation of nozzles on board should reflect the
arrangement successfully tested in accordance with the appendix to these Guidelines. If a specific
arrangement of the nozzles is foreseen on board, deviating from the one tested, it can be accepted
provided such arrangement additionally passes fire tests based on the scenarios of these
Guidelines.
.2 The location, type and characteristics of the nozzles should be within the limits tested in
accordance with the appendix to these Guidelines. Nozzle positioning should take into account
obstructions to the spray of the fire-fighting system. The use of a single row of nozzles or single
nozzles may be accepted for installation where this gives adequate protection according to
paragraph 3.4.2.4 of the appendix.
.3 The piping system should be sized in accordance with a hydraulic calculation technique such as
the Hazen-Williams hydraulic calculation technique* and the Darcy-Weisbach hydraulic calculation
technique, to ensure availability of flows and pressures required for correct performance of the
system.
.4 The system may be grouped into separate sections within a protected space. The capacity and
design of the system should be based on the section demanding the greatest volume of water. In
any case the minimum capacity should be adequate for a single section protecting the largest
single engine, diesel generator or piece of machinery. In multi-engine installations, at least two
sections should be arranged.
.5 Nozzles and piping should not prevent access to engine or machinery for routine maintenance.
In ships fitted with overhead hoists or other moving equipment, nozzles and piping should not be
located to prevent operation of such equipment.
1.4 System components
.1 The system should be available for immediate use and capable of continuously supplying water-
based medium for at least 20 min in order to suppress or extinguish the fire and to prepare for the
discharge of the main fixed fire-extinguishing system within that period of time.
.2 The system and its components should be suitably designed to withstand ambient temperature
changes, vibration, humidity, shock, impact, clogging and corrosion normally encountered in
machinery spaces. Components within the protected spaces should be designed to withstand the
elevated temperatures which could occur during a fire. Components should be tested in
accordance with the listed sections of appendix A of MSC/Circ.1165, as amended by
MSC.1/Circ.1269, as modified below:
* Where the Hazen-Williams Method is used, the following values of the friction factor "C" for different pipe types
which may be considered should apply:
Pipe type C
Black or galvanized mild steel 100, Copper and copper alloys 150, Stainless steel 150
.3 The system and its components should be designed and installed based on international
standards acceptable to the Organization*, and manufactured and tested in accordance with the
appropriate elements of the appendix to these Guidelines.
.4 The electrical components of the pressure source for the system should have a minimum rating
of IPX4** if located in the protected space. Systems requiring an external power source need only
be supplied by the main power source.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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.5 The water supply for local application systems may be fed from the supply to a water-based
main fire-fighting system, providing that adequate water quantity and pressure are available to
operate both systems for the required period of time. Local application systems may form a
section(s) of a water-based main fire-extinguishing system provided that all requirements of
SOLAS regulation II-2/10.5, these Guidelines, and MSC/Circ.1165, as amended by
MSC.1/Circ.1237 and MSC.1/Circ.1269, are met, and the systems are capable of being isolated
from the other sections of the main system.
.6 A means for testing the operation of the system for assuring the required pressure and flow
should be provided.
.7 Spare parts and operating and maintenance instructions for the system should be provided as
recommended by the manufacturer.
.8 A fitting should be installed on the discharge piping of open head systems to permit blowing air
through the system during testing to check for possible obstructions.
* Pending the development of international standards acceptable to the Organization national standards as
prescribed by the Administration should be applied.
** X means the characteristic numeral used to mark the degree of protection against access to hazardous parts
and ingress of solid foreign objects, which could be 0.1 to 6.
1.5 Protection of applications in category A machinery spaces, and applications of similar
risk in other spaces.
With the GW Model M series, GW Sprinkler offers a series of Low Pressure Water Mist systems, for fixed
installation, for fire protection of Category A machinery spaces, and other spaces with applications of similar
high fire risks.
The GW Model M series contain GW Model M5 Local Application System, which is described in this manual,
(Manual no. 846) and GW Model M5/M2 Full Flooding System which are described in GW Manual No. 894.
The GW Model M5 Local Application System is tested and approved in accordance with the requirements of
IMO MSC.1/Circ. 913. The GW Model M5/M2 Full Flooding System has been tested in accordance with IMO
MSC 668/728 for protection of Category A Class 3 machinery spaces, and Factory Mutual Standard No.860
for the protection of Machinery Spaces with Volumes Exceeding 260m3
The GW Model M5/M2 Full Flooding system is water based main fire extinguishing system for engine rooms.
It may be combined with the GW Model M5 Local Application System, so that the two fire fighting systems
share the same pump and nozzle pipe system.
The GW Model M5 Local Application System is installed for protection of "hot spots" in maritime category A
machinery spaces in accordance with MSC.1/Circ. 1387, and land based spaces of similar high fire risks.
The GW Model M5/M2 MisterySpray system is installed as the main fire extinguishing system.
This manual No. 846 describes the function and design, which together with the applicable IMO Circulars
MSC.1/Circ. 1387, and SOLAS are necessary for designing local application installations for engine rooms.
1.6 System performance.
The GW Model M5 Local Application Fire Protection System is designed to accommodate the requirements
of the International Maritime Organisation for water based local application protection in category A
machinery spaces, as described in MSC.1/Circ. 1387. The local application fire protection systems are
additional systems to the main fire fighting systems installed in the engine rooms.
In accordance with MSC.1/Circ. 1387, Local Application Protection Systems shall be installed to provide the
possibility for immediate localised fire fighting directly on high-risk applications. The system should be

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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installed in such a way that the activation of a nozzle zone does not affect the performances of the
applications in the engine rooms. It should be possible to activate local application systems without having to
evacuate persons from the space.
A Local Application Fire Protection System limits the damages, it cools and it allows additional manual fire
fighting to take place, and hereby provides time to activate the main fire fighting system of the engine room if
that should become necessary.
Local application fire protection systems are only for indoor fire fighting. Strong draft in the protected area
should be avoided/prevented, when systems are activated.
1.7 Low water pressures. Low water flows. Wide installation heights. Low electric power
requirements.
The GW Model M5 Water Mist Nozzle has a hydraulic k-value of 5 (l/min \bar). The GW Model M5 Local
Application Fire Protection System controls fires with low-pressure water mist system. 90% of the water
sprayed from the GW Model M5 nozzles is distributed in water droplets, which are smaller than 250 µm in
diameter. The system has passed the IMO MSC.1/Circ.913 (acceptable to MSC.1/Circ 1387) fire test
requirements with an array of only four nozzles.
This allows, in accordance with MSC.1/Circ. 1387, applications to be locally fire protected with GW Model M5
nozzles installed only above the periphery and within the foot print of the protected area. Attention should be
made to obstructions between the nozzles and the application surfaces (chapter 2.3).
The power required for a water mist system (E) is a function the efficiency factor () times the water pressure
(P) times the water flow (Q): E =  x P x Q
From this formula it is obvious that low-pressure (P), results in low power requirements.
Nozzle installation
heights above fire risk
(metres)
Minimum water pressure
on Nozzles
(Bar)
Maximum spacing
between pendent
installed nozzles above
applications
(Metres)
Minimum water density
on applications.
(mm/m per min)
0.5m to 8m 3.5 bar 3m 1.0
>8m to 14.5m 9 bar 3m 1.7
Table 1.1 Installation parameters for GW M5 nozzles in local application systems in accordance with
MSC.1/Circ. 1387.
The wide tolerances in installation heights makes the GW Model M5 Local Application System suitable for
installation in almost all types of engine rooms, in almost all types of ships. The high installation height allows
that nozzles are installed above hoists and other moving equipment in the engine rooms. It also allows
people to work on the applications without having to dismount the local fire fighting system.
Local Application Systems may, in accordance with MSC.1/Circ. 1387, be directly connected to the main
switchboard, or to the water supply of a main fire fighting system. The requirements to power and water
supply is that the systems are cable of supplying water for minimum 20 minutes to the application zone,
which requires the highest water flow. (For applications, installed close to each other, the requirement may
be to supply water to two applications.)
The little power requirements of the system, and the little water-flow requirements of the system sets low
requirements to the power supply, and the flow supply. GW Model M5 Local Application Systems may
therefore often be installed in ships without having to install additional power supply, or pump supplies.
1.8 Fire hazards and fuels:
GW Model M5 Local Application System has been tested in accordance with the requirements of IMO
MSC.1/Circ. 913 (acceptable to MSC.1/Circ. 1387) for the protection of local applications. The test fires in
this scenario are designed by the International Maritime Organisation. The fires are chosen to represent fires
in high-risk applications, where the dominant fire load consists of heated heavy fuel, diesel fuel and
lubrication oils under pressure.
The "hot spots" to be protected are described in SOLAS. These applications are typically: engine tops, boiler
fronts, oil separators, fuel heaters etc.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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1.9 Water as extinguishing agent:
The extinguishing agent of the GW Model M5 Local Application System is water without any extinguishing
enhancing agents. This makes the GW Model M5 Local Application System an environmental friendly fire
fighting system for maritime engine rooms.
The GW Model M5 water mist nozzles distribute 90% of the total amount of water in droplet with diameters
less than 0.250mm. (Dv90 = 250m). The unique distribution of drop size makes it possible to fight fires from
0.5m to 14.5m above the fire risk, with very small water densities.
The water, which is supplied to the nozzles, must be free of impurities. Fresh water and seawater may be
used as extinguishing agents. It is important that the systems are designed for the water quality, which is
used in the system.
Seawater is corrosive, and seawater may leave impurities on internal surfaces of pipes and components. It is
therefore important that pipes and components are firmly rinsed (flushed) with fresh water after having been
exposed to seawater.
1.10 Key system components:
The GW Model M5 System contains two key system components. Both manufactured by GW Sprinkler.
1: The GW Model M5 Water Mist Nozzles: The nozzles atomise water to a water mist with a
distinct droplet size pattern, and which distributes the water mist to the place on fire.
2: The GW Control Units: The control unit satisfy the requirements in MSC.1/Circ. 1387 to
control and monitoring of systems, and provides the requested features of:
 Control of water to the nozzle application zones.
 Isolation of nozzle zones.
 Activation of nozzle zones.
 Filtration of water to nozzle zones.
 Functional tests.
 Activation alarms.
 Nozzle zone drain facilities.
 Monitoring.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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2 Nozzle system and system installation requirements.
2.1 GW M5 Water Mist Nozzle design and nozzle installation:
The GW model M5 Nozzle is a key component in the GW model M5 Local Application Systems.
Key parameters
Specific for GW Model M5 Nozzles
Nozzle connection
½"
BSPT Thread
Nozzle materials
System with fresh water priming
Systems for sea-water
SnNi plated Brass, w. SS 316 deflectors &
filter
SS 316 nozzles
Nozzle protection Transport/blow-off nozzle cap.
Caps should stay on nozzles when being
installed in pipe work. Caps should stay on
nozzles installed in spaces where objects
may risk touching nozzles. Stainless steel
Caps will blow off from water pressure in
pipe system, at system release.
Nozzle k-factor (water) 5 (kg/min bar)
Droplet size. (Dv90) 250 m
Smallest water passage Filter: 1mm, Orifices: 2mm
Water pressures 3.5 bar - 16 bar
Vertical installation heights above fire
risks / minimum water pressure on
pendent nozzles:
Installation height Water pressure
0.5m - 8m 3.5 - 10 (bar)
8m - 14.5m 9 - 10 (bar)
Nozzle spacing for vertical installed
nozzles
Maximum 3m between nozzles
Minimum Water flows and waters
densities for pendent installed Nozzles. Installation
height over
the fire risk
(m)
Minimum
water flow
from each
nozzle
(l/min.)
Minimum
water density
on
application
food-print
(mm/min)
0.5m - 8m 9.4 (l/min) 1.0 (mm/min)
8m - 14.5m 15 (l/min) 1.7 (mm/min)
Maximum obstructions between
pendent installed nozzles and fire risk
(obstructions larger than 0.5m wide.)
Before additional nozzle should be
installed.
The object seen from single nozzle must
not obstruct more then 20 of the spray
The object seen from the fire risk must not
obstruct more than 20.
(see also chapter 2, 3)
Horizontal installed nozzles Chapter 2, 3
Nozzle pipes GW Recommend the use of stainless steel
pipes for nozzle pipes. Systems shall be
hydraulic calculated.
Table 2: GW-M5 Nozzle design and nozzle characteristics.
2.2 Nozzle installation in machinery spaces:
Nozzles and pipe system should be installed by people, who have the necessary skills and understanding of
installing water mist sprinkler systems. The installers should know this manual, and they should be aware of
the risks of system mal-function, if the instructions and precautions listed in this manual are not followed.
Nozzles should be installed in such a way that installation heights, nozzle distances and water pressures, as
listed in table 2, are satisfied.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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Nozzle pipe work should be hydraulic calculated to ensure that the water pressure satisfy the recommended
water pressure on all nozzles in an activated nozzle zone.
Nozzle pipe system should be made in materials, which are corrosion proof to the extinguishing agent, and
which do not cause galvanic corrosion between pipes and components, or pipes and pipe supports. GW
Sprinkler recommends the use of stainless steel for nozzle pipes.
Nozzle pipe support must be designed to withstand vibrations and movement, which might occur on ships at
sea.
Nozzle pipes and other pipe-works should be designed and installed in such a way, that the pipe works do
not interfere with the normal use and maintenance, which take place in the space.
Nozzle pipe-systems should be designed in such a way that nozzles only are installed only so that there is
no risk of damaging the pipe system, or the nozzles.
Nozzle pipes should, when possible, be installed above hoists and other moving equipment.
Nozzle pipe-work should be installed away from door openings and hatches, and other areas where nozzle
pipes or nozzles may limit the free movement of personal in the engine room.
Nozzle pipe-work should be installed away from machinery and areas where maintenance often takes place,
or where there is a risk that the nozzle spray might be obstructed.
Nozzle pipes and nozzles should be installed in such a way that it is not necessary to dismount pipes or
nozzles to be able to maintain or repair machinery or application in the engine room.
Before installing the nozzles. it should be checked that the female nozzle fittings are positioned in such a
way that the nozzles will be correctly positioned. This is easily done with a ½" BSP threaded pipe temporarily
screwed into the fitting to indicate the nozzle direction.
Nozzles should only be installed in the pipe work, after that the full pipe-work has been installed and fully
secured, and after all internal water-ways have been rinsed for impurities, and dried with compressed air.
Nozzles should be installed using a nozzle spanner for the M-series nozzles. The transport cap should be
left on while installing the nozzles, not to risk damaging the nozzles. Nozzles should be tightened to the pipe
system ½" female BSP thread applying a torque of 4 Nm  1Nm.
If a nozzle deflector pin is bent, off centre to the orifice hole, or knocked up against the orifice hole, the
nozzle will not distribute the water correctly. Such damaged nozzles should be replaced with new.
When installing nozzles and pipes, it is important only to apply thread sealant on the male parts, and to
ensure that there are no sealant surfaces internally in the pipe system. This is important to avoid orifices
from clogging.
Threaded female parts should be firmly cleaned before assembled with male parts, to avoid any impurities in
the pipe.
2.3 Obstructions Between Applications and Pendent Installed Nozzles
Caution should be taken to avoid obstructions between nozzles and the fire risks.
Additional nozzles should be installed if obstructions are wider than 0.5m, and shields an angle wider than
20, when seen from a nozzle, or when seen from the fire risk. (Fig. B1 & B2)
If the obstruction is located between two nozzles the shielded angle from a single nozzle may be 40.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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2.4 Additional Nozzles
Additional nozzles should be installed to provide coverage on shielded surfaces (see 2.3). Additional nozzles
may be installed in vertical position below the obstructions, or the nozzles may be installed in horizontal
position away from the footprint of the application.
The number of additional nozzles needed is calculated from the maximum from the Nominal Spray Angle,
and the distance from the nozzles to the object. The whole footprint surface of the application should be
covered, and all shielded surfaces should be covered, too. The Nominal Spray Angles are shown in fig. C1
& C2.
2.5 Horizontal installed Nozzles:
GW Model M5 Nozzles may be installed in horizontal position. This position is an advantage when protection
applications surrounded with narrow space. Horizontal installation of nozzles may also be an advantage
when supplying water coverage below obstructions. (Fig C2)
Horizontal installed nozzles may be installed to spray in parallel with the application surfaces, or to spray
directly on to the surfaces.
2.5.1 Nozzles installed horizontally to spray in parallel with the application surfaces:
Water Mist sprayed in parallel with the application surfaces provides a good protection of applications
surrounded with narrow space, or where a good water mist protection in front of an application is necessary
because of risks of spray fires. The best protection is achieved when the horizontal installed nozzles are
spraying against each other. Design parameters for parallel installed horizontal nozzles are shown in
Fig. C1 (installation parameters) and Fig. B3 & B4 (obstruction of sprays).
2.5.2 Nozzles installed horizontally to spray direct on the application surfaces:
Water Mist may also be aimed to spray directly on to the application surface. For such installations the
maximum distance from GW Model M5 nozzle to the application surface is 3m. The spray angle may be
calculated to be 90, and the maximum spray diameter to be 3m. (Fig. C2).
An obstruction must not cover an angle larger than 20 when regarded from the nozzle, and the place of fire.
(Fig. B3).
3 System design
3.1 Overall system design:
Fig. A2 shows a typical design of a Local Application System. Variations from the design may be acceptable.
Examples here of are found described in fig. D1 & D2, and in the description of the designs in chapter 3.1.
3.1.1 Guidelines and recommendations:
GW Model M5 Local Application Water Mist systems should be designed in accordance with the
guidelines of the International Maritime Organisation (IMO) MSC.1/Circ. 1387, and the guidelines and
requirements of the authorities and societies in request.
This manual does not include all the requirements of all authorities and societies. Therefore GW Sprinkler
recommends system designers to consult the authorities and societies in request, and to get their
acceptance of the system designs before the systems are quoted and installed.
3.1.2 Activation times:
Local application protection systems should be designed for immediate activation in case of fires.
The systems should be designed for continuous flow for at least 20 minutes-duration time.
3.1.3 Hydraulic calculated systems:
Local application systems shall be hydraulic designed to be cable of supplying the required pressure and
flow at the most demanding nozzle zone. (See table 1). The local application system should be cable of

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
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supplying two local application zones with water, if two high risk applications are positioned closed to each
other, and if there is a risk of that fire may spread from the one application to the other.
Hazen-Williams or Darcy-Weisbach model may be used for hydraulic calculation of the systems.
Considerations should be taken to filters in the system, when calculating the systems.
3.1.4 Power supplies:
Power to the system may be taken from the main switchboard of the ship, if this is sufficient to supply the
system, as well as the ship with the necessary power. In case of fire, priorities should be taken to ensure that
the requested power supply are available for the fire fighting system.
Power supply should be outside the protected location.
3.1.5 Water Supplies:
Water supplies may be shared with a main fire fighting system, provided that this system have the sufficient
capacity to simultaneously supply the main fire fighting system, and the most demanding system of the local
application system. The local application system(s) shall be capable of being isolated from the other sections
of the main system.
If combined with a water based main fire fighting system for engine rooms, it is not required that the two
systems are simultaneously activated, however the system should have the capacity of supplying water to
the most demanding local application zone for at least 20 minutes. Hereafter the system should be able to
perform as a main fire fighting system.
Pumps etc. should be installed outside the protected area.
The water supply should be designed for the possibility of immediate activation of the system. This is most
often done by pressurising the feeding pipes from the pump to the Control Unit Valves of the local application
zones, as in traditional wet pipe systems. In traditional wet pipe sprinkler systems a pressure tank keeps the
water in the feeding pipes pressurised. Fig. D1. An other alternative is to install a small pump to the feeding
pipes (jockey pump); to keep the pipes pressurised with fresh water. Fig. D2. The benefits of the pressure
tank, is that the use of sea-water in the pipe system may be avoided, depending on the size of local
application zone systems, and the size of the tank. The benefit of the jockey pump solution is the small
installation. Both the pressure tank and the jockey pump should be installed outside the protected area.
3.1.6 System activation:
Local application systems should always have manual activation.
Automatic activation may be installed, as additional activation system to the manual activation, in non-
manned engine rooms. Automatic activation systems should be activated from double knock detection /
activation systems acceptable to the authorities and societies in request. A sign, which warns people about
automatic release of water mist fire fighting system should be placed at the entrance to the protected space
where automatic activated local application systems are installed.
There shall be at least two manual activation stations for each local application nozzle zone. The manual
activation stations should be positioned at locations, which are easy to access. One activation station should
be installed inside the protected space, and one activation station should be located outside the protected
space. The activation stations should be clearly marked with the application system they activate, and how to
operate the system. Manual system activation stations should be protected against accidental activation.
3.1.7 Design of pipe installation:
Systems should be designed and installed in ways, which make it easy to maintain components and
systems.
Pipes, components, and nozzles should be installed so that they are protected against damage. Attendance
should be taken to design the pipe system in such a way that pipes and components do not need to be
dismounted when applications are maintained or repaired. Pipes and components should not obstruct
passages, openings, doors or hatches in the room.
Pipes and nozzles should be installed above hoists and other moving equipment in the location.
Pipes and components should be chosen in materials suited for the extinguishing agent (fresh or seawater)
and the ambient temperature. Attention should be taken to avoid corrosion of the system. Where possible
pressurised pipe system should be charged with clean fresh water. Means of connection to fresh water
supply, and sufficient drainage, should be made to allow all pipes to be firmly rinsed with fresh water after
having been exposed to seawater.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
13
GW Sprinkler recommends piping to be made in stainless steel, and joints between stainless steel pipes and
system components in other materials to be flanged, and isolated from each other with the flange gaskets,
and plastic isolation bushes on the flange bolts.
Water Mist systems require extra high attention on avoiding impurities in the pipe work.
After the installation of pipes, the internal surfaces of the pipes should be firmly cleaned from shavings,
chips, and left over sealant materials, before system components are joined to the pipes. When sealing
threaded joints, the sealant should only be applied on the male thread, and care should be taken not to apply
sealant materials in the cavities. Attention should be taken to firmly clean re-used thread for old sealant
before re-using the threads.
If Local Application Systems are combined with a main fire fighting system, strainers should be installed
between the pipes of the main fire fighting system and the local application system. (Strainers are integrated
in the GW Control Units).
Pipe system should always be rinsed with lots of fresh water after being exposed to seawater.
A fitting should be installed on the discharge piping of open head systems to permit blowing air through the
system during testing to check for possible obstructions.
3.1.8 System supports:
The support system should be accepted by the authorities, and by the societies in charge. The local
application systems should be supported with pipe supports, which holds the system firmly supported. The
spacing of the supports should be sufficiently small not to allow the pipe system to move, and cause
vibrations in the pipe system. The supports should be strong, and they should allow the system to be
maintained, and sections to be changed if necessary. Supports should be attached to foundations, which are
ridged and strong enough to support the pipe system against the vibrations of the ship, and the harshest
movements of the ship at sea.
Supports should be protected against corrosion. If steel supports are used together with stainless steel or
copper pipes, the two materials should be galvanic isolated from each other to prevent galvanic corrosion
between the two metal alloys.
4. System Control Valve Units.
4.1 GW Control Units in general:
GW Model M5 Local Application Systems are controlled with the GW Control Units, which control the water
access from the wet pressurised feeding pipes to the dry nozzle zone pipes of the systems. (Fig. E2)
The GW Control Units provide the control, activation, tests, drain and monitoring features, as required by The
International Maritime Organisation in their circular MSC Circ. MSC.1/Circ. 1387.
The GW Control Units provide the following features:
- Filtration of water from feeding pipes to nozzle pipes.
- Separation valve for the individual nozzle pipe zone.
- System connection to activation/detection systems, and closing feature for the water access
to the individual nozzle zones.
- System activation alarm for the individual nozzle zones.
- Nozzle pipe drain.
- Test features for functional tests of water supply and the individual local application zones.
- Monitoring of water pressure in feeding pipes.
- Monitoring of valves in the control system.
The GW Control Units are prepared for multiple activation stations. GW control units are hydraulic or electric
controlled. Control units are prepared for activation from manual activation stations, as well as automatic
activation from electric detection/activation, or automatic activation from a hydraulic activation system with
electrically activated heat detectors (sprinklers).

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
14
4.1.1 Sizes and hydraulic connections:
Control Unit Size Connections to feeding
and nozzle pipes
Connections to drain
pipe
Connection to hydraulic
activation.
1" DN 25 1" BSP female thread 1" BSP female thread ½" BSP female thread
1 1/4" DN 32* 1 1/4" BSP female thread 1" BSP female thread ½" BSP female thread
1½" DN 40 1½" BSP female thread 1½"BSP female thread ½" BSP female thread
2" DN 50 2" PN 16 BS Flanges 2" BSP female thread ½" BSP female thread
2½" DN 60 2½" PN 16 BS Flanges 2" BSP female thread ½" BSP female thread
3" DN 80* 3" PN 16 BS Flanges 2" BSP female thread ½" BSP female thread
Table 3 Hydraulic connections for GW Control Units.
* 1 1/4" and 3" are not standard sizes. Extended delivery times may be expected.
4.1.2 Sizes and friction losses:
Control Unit Size Water flow through Control Unit (Litres/min)
With 4 bar back-pressure in down-stream nozzle
pipes.
Water pressures in feeding pipe
5 bar
7 bar
8 bar
9,5 bar
12 bar
Differential pressure between inlet and outlet: 1 bar 3 bar 4 bar 5.5 bar 8 bar
1" 67 148 185 - 265
1½" 279 463 518 604 -
2" 408 692 - - -
2½" 764 - - - -
Table 4: Friction loss in GW Control Units, with 4 bar backpressure in nozzle pipes.
4.1.3 Components and materials:
Main components are shown on fig. E2:
No.
Fig.E3
Component Basic materials Coatings and
specialities
1 & 9 Flanges on 2", 2½", 3" Control Units
Threaded connections on 1",1 1/4", 1½"
Control Units
Steel
Brass/bronze
Galvanised
Natural or chromed
2 System Isolation Valve Brass/bronze Natural or chromed
3 Filter Bronze w. stainless steel
filter basket
Natural or chromed
4 Inlet pressure gauge Brass internals, glycerine
filled
Steel housing
5 Control Valve Cast ductile iron Epoxy coated
6 Pressure switch Brass internals,
galvanised steel
connection
Galvanised
7 Drain Valve Brass/bronze Natural or chrome
8 Outlet Valve Brass/bronze Natural or chrome
10 Outlet pressure gauge Brass internals, glycerine
filled
Steel housing
13 Plug and trim pipes Brass/Steel Galvanised
14 & 15 By-pass valve & direct activation valve Brass Chrome
16 Connection Box Plastic IP 65
*11
12
Impulse solenoid valve *
Filter
Brass
Brass/Stainless steel
Natural
Natural
Table 5: Standard GW Control Unit, Components and materials. * Solenoid activation and filter is an option.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
15
4.1.4 Electric connections:
4.1.4.1 Monitoring system:
The electric connections for the monitoring system are an IP 65 connection box, which are attached to the
GW Control Unit. The electric connections are shown in fig. E4.
The Connection Box are prepared for ø4mm -ø6mm cable connection. (see Fig E4)
The monitoring current: 24V DC.
The monitoring system consists off:
Reference to
fig E4 & fig E2
Component
Positions in standby model
Component
Switch
SW1 & 8
Micro-switch on outlet valve Open On
SW2 & 14
Micro-switch on By-pass Valve Open On
SW3 & 7 Micro-switch on Drain Valve Closed On
SW 4 & 2 Micro-switch on System isolation Valve Open On
PSW & 6 Pressure Switch Pressure-less On
Table 6: Monitoring system for GW Control Units.
The Micro-switches and the pressure switch are all connected in series in the connection box. They should
be connected to a monitoring system, which provides an alarm when the electric monitoring circuit
disconnects.
4.1.4.2 Impulse Solenoid Valve:
For electric activation an impulse solenoid valve may as an option be fitted the Control Unit.
The Control Valve will open and allow water to flow into the dry nozzle pipes when the Solenoid Valves
opens. The Control Valve will automatically close for the water exit to the nozzle pipe system when the
solenoid valve is closed.
The impulse solenoid only needs a short electric 24Vdc impulse to open. It stays open until it is closed
deliberately with an electric 24 V DC signal on an other lead termination port, than that of the opening
impulse.
An open electric activated control unit, continue to stay open, also if the detection/activation/power panel
breaks down.
Impulse solenoid valves should only be installed with a filter (mesh size < 1mm) up-stream the Solenoid
valves. The filter should be cleaned regular, and the solenoid valves should also be operated, and checked
and maintained in regular intervals. At least every two years the diaphragm should be changed with new.
Referring to the terminals on the impulse solenoid fig. E3: The solenoid is activated with an electric impulse
on terminal 2 & 3. The solenoid is re-closed with an electric impulse on terminal 1& 3.
The Impulse solenoid valve is connected the GW Control Units in such a way that an additional drain from
the solenoid valves is not necessary.
Control Valves with impulse solenoid valves may be manual activated from manual controlled electric
switches. The switches have two active positions, and a neutral position. The switches should clearly be
marked with position for opening the valve, and position for closing the valve. The switch should
automatically return to neutral.
Activation switches should be protected against accidental activation.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
16
4.2 The Performance of GW Control Unit.
Fig. E5: The figure shows the performance of the GW Control Units.
4.2.1 Control Unit in standby model:
Fig. E5 - Shows the GW Control Unit in standby model.
Water from the wet feeding pipe pressurises the Control Unit upstream the control valve, including the inlet,
and the pilot chamber of the control valve, and the wet activation pipe system, which is connected to the
Control Unit.
The check-valve integrated in the valve plate of the Control Valve allows water to flow from the feeding pipes
into the pilot camber of the Control Valve, and from here into the wet pipes of the hydraulic activation
system, if such is fitted to the Control Unit.
(When pressurising the hydraulic activation system it is important that the by-pass Valve (Fig. E2-No.14) is
closed. The by-pass valve shall be fully opened when the hydraulic activation system is fully filled and
pressurised with pilot water from the Control Unit)
In standby model the pilot water pressure is the same, or higher, than the water pressure in the feeding
pipes.
Reference
s to fig.
E1,E2 & E3
& E5
Valve Position in standby Position of corresponding
monitoring switch
2 System isolation valve Fully Open On
5 Control Valve Fully Closed -
7 Drain Valve Fully Closed On
8 Outlet Valve Fully Open On
14 by-pass Valve Fully Open On
12,15, and
detectors
and
activation
valves
remote
from the
control unit
Solenoid valves, Manual
release valves, sprinkler
detectors etc.
Valve in the activation
system, with the exception
of the by-pass valve
Fully Closed -
Table 7: Positions of control unit valves with, local application system in standby model.
The electric monitoring system does not provide any alarms when the Control Unit is in standby mode.
4.2.2 Activation of the Local application System:
Referring to Fig. E5.
The GW Control Unit opens and release water into the dry nozzle pipes, when the pilot water is release from
the pilot chamber of the control unit.
The pilot water flows from the pilot chamber if a valve, or sprinkler detectors in the hydraulic activation line
are opened. (Fig. E5 -B)
The pilot water can also flow from the pilot chamber if the control valve is fitted with a solenoid valve for
electric release, and the solenoid valve is opened. (Fig. E5-C).
The Control Unit opens because the water pressure below the valve plate becomes higher than the pressure
from the spring and the pilot water pressure in the pilot chamber.
Water, which flows into the nozzle pipes, passes the Y-strainer in the Control Unit, which catches the
impurities that the water contains, so that the nozzles do not block.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
17
4.2.3 Closing and returning the Control Unit back to standby model after activation:
Referring to fig. E3 and E5.
4.2.3.1 Control Unit activated on solenoid valve, or manual released valve.
After the Control Unit has been activated. The Control Unit returns automatically to standby model when the
activation valve is re-closed.
When the activation valve is closed, the pilot chamber is sealed. Water flowing through the check-valve in
the control valve plate allows that the pilot water pressure in the pilot chamber becomes the same pressure
as that of the water supply pressure. The spring in the pilot chamber making the valve plate gasket seal
against the valve seat. The water stops flowing from the feeding pipes into the nozzle system. The control
unit is closed, and it has been returned to its standby mode.
GW Sprinkler recommends that pipes, which have been exposed to seawater, be firmly rinsed with fresh-
water. GW Sprinkler does also recommend that filters cleaned after the control unit has been activated.
To clean filters, the separation valve is closed, and filters are cleaned, and resealed. The separation valve is
slowly opened, and the control unit has been returned to standby mode.
4.2.3.2 Control Unit activated from sprinkler detectors.
If the control unit is activated from sprinkler detectors in the hydraulic activation system:
-The separation valve (Fig E2-2) is closed. Water stops flowing from the open nozzles and from the broken
sprinkler detectors.
-The sprinkler detectors are replaced with new.
- Filters are checked and cleaned, and filter baskets are re-fitted and sealed.
- If the pipe system has been exposed to seawater, the exposed pipes are firmly rinsed with fresh water.
- The by-pass valve is closed. (Fig. E1,E2 - 14)
- The separation valve is slowly opened, to let water flow into the pilot chamber and the hydraulic activation
system.
- The hydraulic activation system is bled.
- The by-pass valve is re-opened,
- And the control Unit has been returned to standby mode.
4.2.4 Pre-Action Activation Trim:
Pre-Action trim (see fig. E3)
In pre-action trim the hydraulic activation system contains a by-pass valve, an impulse solenoid valve and
electrically activated heat detectors. The solenoid valve and electrical heat detector (sprinkler) are
independently connected to the smoke detection system of the engine room.
To activate the system, the smoke/flame detection system shall independently activate the solenoid valve,
and the electrical heat detector, before the pilot water is released from the pilot chamber of the control unit
and water is allowed to flow into the open nozzle.
Failures to the hydraulic activation pipes or sprinkler detectors without electric signal to the solenoid valve
will not activate the system, and fail signal to the solenoid valve without release of electrical heat detectors
will also not activate the system. Pre-action control units are manual released from additional solenoid valve
or hydraulic activation system which is connected to the pilot chamber of the control valve in parallel with the
pre-action control pipes.
When pre-action activation systems with pilot water the by-pass valve is opened and the solenoid valve is
closed to set the system in stand-by mode.
4.3 Installation and tests of control Units:
4.3.1 Installation position:
Control Units are supplied as one whole unit, ready for installation in pipe work between feeding pipes and
nozzle pipes. Control Units should only installed in horizontal position, with the pilot chamber pointing up-
wards, and with the flow arrow pointing from the feeding pipe to the nozzle pipe system.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
18
4.3.2 Hydraulic installation:
Before the control unit is installed, it is checked for visual faults.
GW Sprinkler recommends that the installer installs control units with flange connections, also for control
units smaller than 2".
The installer should connect the drain valve on the Control Unit to a drain with the sufficient capacity to be
able to drain full flow from the Control Unit.
4.3.3 Electric installation:
The installer should only use electric wiring approved for maritime use by the authorities and societies in
charge. The wiring should be strapped, so that wires do not swing, and cause the electric system to male
function. See chapter 4.1.4 for electric connections.
The alarm circuits should be connected to relay or panel, to sound alarm when the electric monitoring circuit
is broken.
The installer should consult the authorities and societies in request for their requirements to alarms.
After installation of the Control Unit in the pipe system, and the electric connection of the monitoring system,
the activation system is connected.
The solenoid valve is connected in accordance with chapter 4.1.4. and the figures E5 & E3. The wiring
should be in accordance with the requirements of the societies and authorities in request. Electric wires
should be strapped, to avoid free hanging wires.
4.3.4 Installing & designing hydraulic activation system.
The hydraulic activation system should be installed in accordance with the requirements for support of the
Local Application System in this manual, and as requested by the authorities and the societies in request.
Pipes should be in stainless steel, and pipes should be of sizes no less than ½".
Hydraulic activation pipe systems should have an equivalent pipe length no more than that of 20m of ½"
stainless steel piping. The hydraulic activation system should be connected to the ½" by-pass valve
connected to the Control Unit trim, and marked with a black band.
4.3.5 Test of monitoring circuits..
After installation the function of the control valve is tested.
The monitoring circuits are tested. The valves on the Control Unit are opened and closed, and it controlled
that alarm sounds when the valves are not in the standby mode positions. (Table 7)
4.3.6 Functional tests of Control Unit:
Functional test is conducted to check the performance of the control unit, the activation stations, and the
alarm from the pressure switch.
To conduct functional in connection with system installation:
- Separation valves on all Control Units are closed. (Fig. E1 & E2 - No. 2)
- Outlet Valve is closed on control Unit to be tested. (Fig. E1 & E2 - No.8)
- Drain Valve is opened on Control Unit to be tested. ((Fig. E1 & E2 - No.7)
- The By-pass valve is closed. (Fig. E1 & E2 - No.14)
- The Feeding Pipe is pressurised with water.
- The Separation Valve is slowly opened.
- The Hydraulic Activation system is bled (Fig. E3 & E5).
- The By-pass valve is opened.
- Open the activation valves, which are connected to the Control Unit being tests, one at the time.
- Control on pressure alarm, and pressure gauge ((Fig. E1 & E2 - No. 6 &10), that water pressure
immediately builds up at the control valve outlet, when each of the activation valves is being opened. It
should also be checked that the Control Unit closes, and water pressure disappears from the control valve
outlet when the activation valves are being closed. A delay in closing the Control Valve might occur. The
Check Valve in the control valve plate, and the filter and the solenoid valve should be cleaned, if the delay in
closing the valve is larger than 30 sec.
- After the test the Control Unit should be left in standby mode. (See table 7)
Continue to test the other Control Units in the Local Application Installation.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
19
4.3.7 Spares which should be available on site
Component Per Control
Unit
Per 2 Control
Units
Per 4 control
Units
Per 6 Control
units
Control valve plate gasket * 1 1 2 2
Control Valve diaphragm * 1 1 2 2
Control Valve check-valve filter* 1 1 1 2
Control valve check-valve bolt * - - - 1
Large filter basket - - 1 1
Solenoid valve filter basket 1 1 1 1
Solenoid valve repair set, diaphragm, etc. 1 1 1 2
Pressure switch , pressure gauge - - 1 1
M5 Nozzles 1 2 4 6
Table 8: Recommended spares available when handling over installations. * All enclosed in Control Unit
Spare Kit.
4.4 Maintenance and tests of Control Units:
GW Sprinkler recommends that Control Units be maintained in regular intervals.
Control Units should always be repaired and maintained when faults are found.
Maintenance action
Monthly
Every ½ year
Annually
Every 2 years
Functional test of monitoring
circuits
x
Functional tests of Solenoid
valves
x
Functional tests of Control Valve x
Cleaning of strainers x
Cleaning of check valve in control
valve valve-plate
x
Cleaning of Solenoid valve, and
solenoid valve filter.
x
Change control valves diaphragm,
gasket, filter and check valve nut.
X
(spares
package)
Change of solenoid valve
diaphragm
X
(new
diaphragm)
Table 9: Tests, services and maintenance of Control Valve Units, and spares required for the maintenance.
Other system components should be tested and maintained in accordance with the requirements of SOLAS,
the authorities, and the societies in request, and the guidelines of the component manufacturers.
GW Sprinkler recommends a service log for each system installed.

GW Manual No. 846
M5 / Local Application Fire Protection of Category A Engine Rooms– IMO / MSC.1/Circ. 1387
Dated: 04-06-2014
20
4.5 Checklist for faults:
If fault is found, first check with table 7 that all valves are in standby mode.
Fault observed
Possible fault
Cure
Monitor alarm does not sound
when valve is out of standby-mode
Electric Circuit or micro-
switch damaged, or out of
position.
Check electric circuit.
Check that micro-switch on valve is off.
Monitor alarm sounds when all
valves are in standby
System may be operated.
Wire may be broken
Micro-switch may be
damaged, or pushed out
of position to be on.
Pressure switch may e
damaged.
Check if system is activated and water
flows from the system.
Check monitoring circuits.
Check that all micro-switches are on.
Change with new if necessary.
Check that Pressure switch is on. Check
pressure setting. Change with new if
necessary.
Alarm from solenoid valve
monitoring system.
System is activated.
Faults on solenoid.
Faults on electric circuit.
Check that water does not flow from the
system.
Check resistance in the solenoid. Change
with new if necessary.
Check resistance in the electric circuit. Fix
the fault.
Solenoid valve do not activate
control unit
Sufficient electric signal is
not provide to solenoid.
Solenoid valve does not
open sufficiently.
Solenoid valve or filter is
blocked.
Check power supply and wiring for
activation impulse of 24 VDC, min. 8W on
terminal 2 & 3 on solenoid.
Check electric connections on solenoid.
Check resistance on solenoid.
Check and clean solenoid valve, and clean
filter.
Control Unit does not activate
when valve in hydraulic activation
system is operated.
Pilot pressure is not
released
Check that by-pass valve is full open.
Check that the equivalent length of the
hydraulic activation system does not
exceed 20m for ½" stainless steel pipe.
Control Unit does not close when
activation valve is closed
Pilot water pressure does
not build up in the pilot
chamber when activation
valve closes.
Check for leakage in hydraulic activation
system.
If solenoid valve, check solenoid valve
circuit for 24V DC 8W closing signal on
terminal 1 & 3 on solenoid.
Clean solenoid valve and solenoid valve
filter.
Clean check valve, and check valve filter in
control valve plate.
Check control valve diaphragm for ruptures
and holes.
Control Unit leaks internally The valve plate does not
seat right on the valve
seat.
The control valve leaks
because it is slightly open.
The control valve leaks
because of a ruptured
diaphragm.
The control valve leaks
because of dirt between
gasket and valve seat.
The control valve leaks
because of a ruptured
gasket.
Seal leaks in the activation system,
including leaks in the solenoid valve.
Clean seats and gaskets in control valve
and solenoid valve, and change gaskets or
diaphragms if necessary.
Fig. 10: Faults and cures for control units.