Nessie® High Pressure Water Mist Components
for Fire Fighting
Generally
Quick overview of the Nessie product portfolio used in Fire Fighting applications within
Marine, Mobile and Spot systems typically protecting Engines, Turbines, Cable trays, CNC
Machines, Computers, Fast Response Vehicles etc.
Brief description of the functionality of High Pressure Water Mist for Fire Fighting.
Benefits
One supplier of components for High Pressure Water Mist Systems.
Water Mist General
The overall extinguishing principle of Water Mist Systems is that when a Water Mist is
applied into the fire the Water Mist evaporates and turns into steam. This process is very
energy demanding and the temperature of the fire is reduced dramatically and in the same
process expands the Water Mist 1700 times which displaces the air from the fire and the
two of the three main sources for fires are removed and the fire is extinguished.
This process means that water consumption is typically reduced by 6-10 times compared
to conventionally sprinklers and the Water Mist does insignificant damage to engines or
hot metal as well as minimum cleaning is required when used in example Passenger
Cabins, Hotels, Restaurants etc.
The applications for Water Mist Systems is now expanding from the Marine and Offshore
segments, where it has proven to increase the safety onboard, into segments like Tunnels,
Mobile, Computer room and machine protection.
The benefits for tunnels/underground transportation are the small amount of water required
where the distribution of water is the main problem and by using high pressure the size in
pipe installation is reduced significantly.
On mobile system is it possible to build fast response vehicles carrying a small amount of
water. Experience has shown that a fast response vehicle is 2-7 minutes earlier than
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conventional fire trucks and more that 50 % of the fires is extinguished before arrival of the
conventional fire trucks.
For computer room and spot protection is the insurance companies are now in favour of
replacing conventional sprinklers for building protection combined with a High Pressure
Water Mist System for spot protection of the most hazardous areas such as computes, tool
machines, moulding machines etc.
For architectural constructions where space is critical such as large window areas a High
Pressure Water Mist is easy installed because of the small water usage, which results in
very small pipe sizes. Hereby has fire protection system very little influence on the design,
which gives the architect more freedom in the design. In addition has test shown that a
High Pressure Water Mist is having a lot higher cooling effect on large window areas so a
longer escape time can be established for large window areas.
A complete model for Water Mist Fire Fighting Systems is not yet available but it seems
that the smaller drops the better result. By using the smallest possible drops the least
amount of water is used but small drops are difficult to give momentum due to their low
weight, therefore is a High Pressure System the optimum solution today because the High
pressure typically generates drops > 50 micron and gives the drops a required momentum
for a reasonable reach.
Water as Fire
Suppression Agent
Water is properly the most used agent for fire fighting which may be because of its
availability and environmentally friendliness.
When water evaporates it starts acting like an Inert gas although it cannot be considered
as an inert gas one of the characteristics it the displacement of air, which is the fire fighting
principle of inert gases.
Comparing the technical constellation of water to other fire fighting agent’s water is one of
the highest substances with regards to specific heat capacity and heat of evaporation as
illustrated in below figure.
Fire Fighting Agents
Heat of Evap.
3000
Spec. Heat Cap.
2500
1500
1
1000
kJ/kg K
1,5
2000
kJ/kg
2
0,5
500
0
01
13
n
al
o
H
1
Ar
go
n
01
13
d
n
al
o
H
Bl
en
FC
H
C
FC
H
IG
-5
4
A
a
-2
27
e
O
2
C
ito
N
W
at
er
ge
n
0
Cooling effect
Because of the high Heat of Evaporation the absorption of heat from the fire causes a
rapid cooling of the fire. This heat absorption capacity when Water Mist is transferred into
water vapour/steam from 25 ºC is 2500 kJ or approximately 6 times higher than the heat
absorption for CO2.
Compared to conventional sprinklers where the predominately cooling effect is reached by
boiling the water, where the energy required for raising the temperature from 20 ºC to100
ºC for 1 litre of water is 27 kJ.
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Inert effect
The main difference from water to gasses is that water only starts acting like an inert gas
when heat transfers the water mist into water vapour/steam. Because the more common
used liquids have a lower boiling point at atmospheric these liquids is transferred into
gasses when released into the atmosphere and does not require a heat source, which is
illustrated below.
Agent
IG-541 (Inergen)
CO2
Halon 1301
HFC-227ea (FM 200)
Halon 1211
Water
Boiling point at atmospheric
pressure [ºC]
-196
-79
-58
-16
-4
+100
The Water Mist Paradox
The experience with using and testing Fixed Installed Water Mist Systems for fire fighting
is that large fires are extinguished easily but very small fires are difficult or almost
impossible to extinguish. The reason for this paradox is related to the boiling point of water
and the required energy for evaporation is not present at a small fire. The experience from
tests is that a small fire will be kept under control and in most cases is the small fire
extinguished.
Water Mist Flooding
With a very fine Water Mist there is the possibility that the drops will float with the airflow
and as the fire requires air the very small drops will float to the air and may result in a
similar result as a full flooding agent.
To achieve the droplets to float with the air the droplets must be <50 µm or smaller
because the evaporation of larger drops is influenced by the gravity and a float process
becomes unrealistic.
Regulations
Marine (SOLAS II-2)
International Marine Organisation regulations MSC Circ. 668, MSC/Circ. 728 & MSC/Circ.
913 ensure that machinery spaces on vessels are protected effectively against damage
caused by fast spreading class B fires.
The regulations specifies a full flooding system and the tests for Water Mist Systems is
split into three engine room sizes:
• Class 1: ≤ 500 m³.
• Class 2: ≤ 3000 m³.
• Class 3: > 3000 m³.
So far has only Class 2 engine protection been successfully tested with Water Mist
System.
MSC/Circ. 913 states that all engine rooms above 500 m³ must have a water based
system installed for spot protection of hazardous areas in addition to a gas based full
flooding system according to the following specifications:
• New passenger ships > 500 gross tonnes by June 2002.
• New cargo ships > 2,000 gross tonnes by June 2002.
• Existing passenger ships > 2,000 gross tonnes by January 2005.
One of the reasons, besides the fact that < 90 % of all fires on ships starts in the engine
room, for this regulation is that gas protected engine rooms have a very specific procedure
to release the gas system which normally takes 10-20 minutes, where Water Mist Systems
can be released immediately and automatically after detecting the fire, which typically
takes 10-30 seconds after detecting the fire.
The final result in case is saving life and ship and quick repair which reduces the amount
of lost revenue dramatically.
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Mobile Systems
The approval for mobile systems is typically approved in each country and a general
approval is therefore not an option.
Land based systems
Approvals is done from case to case by practical tests.
In certain areas have the insurance companies offer premium reduction because if
installation of High Pressure Water Mist Systems because if the reduced risk water
damages.
Standards
The only existing standard for installation of Water Mist Fire Suppression Systems today is
NFPA 750.
Links
Related links to Water Mist Homepages:
Danfoss:
IWMA:
IMO:
NFPA:
UL:
STUVA:
Sintef:
DBI:
SP:
www.danfoss.com/Nessie/FireFighting/index.asp
www.iwma.net
www.imo.org
www.nfpa.org
www.ul.org
www.stuva.de
www.sintef.no
www.brandteknisk-institut.dk
www.sp.se
Components
In the following is a short technical description made, covering the most common products
used in Fire Fighting Systems.
For additional products and further details please contact the Danfoss, Nessie sales
organisation.
Pumps
The PAH series pumps are designed to supply water flow under high
pressure and is based on the axial piston principle enabling a very light
and compact design.
The pumps are designed with a very high level of total efficiency and for
maintenance free operation with all mowing parts being lubricated by the
water.
The pumps are fixed displacement pumps where the flow is proportional to
the number of revolutions of the input shaft and the pumps displacement.
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Benefits
• Self lubricating by the water. I.e. No maintenance required in the field (Oil change),
High reliability, No risk of mixing oil and water.
• High efficiency (Total > 92 %). I.e. Energy savings, Reduced installation cost.
• Low weight and compact. I.e. Easy installation.
• High Shaft Speed (> 1800 rpm). I.e. Direct mounting to el-motor/combustion
engine, Reduced installation cost, No maintenance in the field, High reliability.
• Very low pressure ripples (< 2 %). I.e. No need for pulsation dampeners, Reduced
risk for water hammer.
• Stainless steel (AISI 304) housing.
• Shock tested to 40g in x-y-z direction.
Technical data:
PAH pumps
Geometric displacement
[cm3/min-1]
Max. Pressure Cont. ]bar] 1)
Max. Pressure Peak [bar]
Max. shaft speed [min-1] 2)
Min. shaft speed [min-1]
Flow at 1500 min-1 3) [l/min]
Weight [kg]
10
12.5
25
32
50
63
70
80
10
12.5
25
32
50
63
70
80
160
220
1800
700
13.5
7.7
160
220
1800
700
17
7.7
160
220
1800
700
34
9.7
160
220
1800
700
44
9.7
160
220
1800
700
70
32
160
220
1800
700
86
32
160
220
1800
700
97
32
160
220
1800
700
112
32
1)
For higher pressure, please contact Danfoss Sales Organisation.
For higher or lower shaft speed please contact Danfoss Sales Organisation.
3)
Flow at maximum pressure continuously.
2)
Temperature:
Water temperature: Min. +3°C to max. +50°C at max. pressure continuously.
Ambient temperature: Min. +0°C to max. +50°C.
Storage temperature: Min. -40°C to max. +70°C.
Filtration:
The applied water must be filtered through a 10 µm abs., β10-value >5000 filter.
Code numbers:
PAH pumps
Order code number
PAH 10
180B0008
PAH 12.5
180B0007
1)
PAH 25
180B0015
1)
PAH 32
180B0016
PAH 50
PAH 63
180B0040
PAH 70
180B0042
PAH 80
180B0041
1)
Housing in aluminium.
Additional technical data:
For further information such as Efficiencies, Suction pressure, Noise levels, Installation,
Mounting, Water types etc please refer to TechNote Nessie Pumps DKCFN.PD.010.A4.02.
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Valves
A complete range of relief-, solenoid & check valves are available in standard housings
and custom designed multi functional blocks. The standard valves are made in AISI 304
stainless steel with AISI 316 as optional. The solenoid valves are ON/OFF types with coils
in IP 67 enclosure and a range of EEx coils is also available.
Pressure setting valves:
Type:
Maximum flow [l/min]
Pressure range Adjustable [bar]
Connecting Ports
Weight
Order code number
VRH 30
VRH 60
VRH 60
VRH 120
VRH 120
30
25-140
G 3/8”
60
25-80
G 1/2”
60
80-140
G 1/2”
120
25-80
G 3/4“
120
80-140
G 3/4“
180G0030
180G0002
180G0003
180G0020
180G0021
For further technical information please refer to TechNote WN.30.A4.02
None return valves:
Type:
VCH 30
VCH 60
VCH 120
Maximum flow [l/min]
Max. pressure [bar]
Opening pressure [bar]
∆p at max. flow [bar]
Connecting Ports
Weight
Order code number
30
300
0.5
2.5
G 3/8”
0.3
180G0030
60
300
0.3
2.5
G 1/2”
0.4
180G0002
120
300
0.3
2.5
G 3/4”
0.6
180G0003
Solenoid valves:
The comprehensive range of solenoid operated sectional valves with features such as
Manual bypass is available and is based on the well proven valves for High Pressure
Water Systems.
The valves are made in AISI 304 as standard and are available in AISI 316 on request.
The coils are ON/OFF type and are available as AC and DC coils for almost all possible
voltages and is also available for Eex applications.
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Technical data
In line and angle valves
Type:
VDHT 3/8
EA 2/2 NC
Maximum flow
Maximum Pressure
Pressure drop at Max flow
Connecting Ports
Weight
Order code number
Order code number with
manual bypass
30 l/min
140 bar
3.5 bar
G 3/8”
1.2 kg
180L0100
Not
available
VDHT 3/8
E 2/2 NC
VDHT 1/2
EA 2/2 NC
VDHT 1/2
E 2/2 NC
VDH 120
E 2/2 NC
30 l/min
140 bar
2.4 bar
G 3/8”
1.2 kg
180L0092
Not
available
60 l/min
140 bar
5.8 bar
G 1/2”
1.2 kg
180G0102
Not
available
60 l/min
140 bar
5.3 bar
G 1/2”
1.2 kg
180L0094
Not
available
120 l/min
140 bar
6.0 bar
G 1/2”
1.8 kg
180L0001
180L0020
In line and angle valves
Type:
VDHT 1” EA 2/2 NC
Rated flow
Rated Pressure
Pressure drop at Max flow
Connecting Ports
Weight
Order code number
Order code number with
manual bypass
VDHT 1” E 2/2 NC
150 l/min
140 bar
4.0 bar
G 1”
kg
T.B.A
Not yet
available
150 l/min
140 bar
6.0 bar
G 1”
kg
T.B.A
Not available
Multi block valves with 2-5 valves
Type:
VDHT 60 EA 2/2 NC
Rated flow
Rated Pressure
Pressure drop at Max flow
Connecting Ports
Weight
Order code number
Order code number with
manual bypass
Coils for solenoid valves
Type:
10 Watt AC Coils
Available voltage
Available frequencies
Enclosure
Connection
Ambient temp.
Weight
Order code number
VDHT 150 EA 2/2 NC
60 l/min
140 bar
5.8 bar
G 3/8” 1/2”, 3/4” & 1”
Depending on no of valves
T.B.A.
Not
available
24, 48, 110, 230, 240
Volt
50 & 60 Hz
IP 67
Terminal box
80 °C
0,30 kg
T.B.A at specification
150 l/min
140 bar
5.0 bar
G 3/4”, 1” & 1”1/4
Depending of no of valves
T.B.A.
Not yet
available
18 Watt DC Coils
Eex Coils
12 & 24 Volt
24 Volt DC &
230/240 volt AC
50 & 60 Hz
IP 67
5 meter cable
40 °C
0,35 kg
T.B.A at specification
IP 67
Terminal box
50 °C
0,30 kg
T.B.A at specification
For further technical information please refer to Tech Note WN.30.A4.02.
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Nozzle inserts:
Nozzles have been a Danfoss specialty for decades. They are tailored for High Pressure
Water application, and is special designed for Fire fighting sprinkler head application and
portable hand guns.
The droplet size delivered depends exclusively on the nozzle pressure. High pressure
causes smaller droplets, and smaller droplets mean faster evaporation or steam
generation.
Technical data
Liter
Liter
US Gallon
US Gallon
Spray
per min.
per hour
per min
per hour
angle
0.42
25.2
0.11
6.6
60º
0.92
55.2
0.24
14.4
60º
1.25
75.0
0.33
19.8
60º
2.17
130
0.70
42.0
60º
2.87
172
0.76
45.6
60º
3.13
188
0.83
49.8
60º
3.36
202
0.89
53.4
60º
5.74
344
1.52
91.2
60º
2.38
130
0.70
42.0
80º
-Liters and gallons per min is measured at 100 bar.
-Ordering codes is for 10 pieces pack.
Max.
pressure
130 bar
130 bar
130 bar
130 bar
130 bar
130 bar
130 bar
130 bar
130 bar
Ordering
code
180Z1910
180Z1915
180Z1918
180z1924
180Z1926
180Z1937
180Z1927
180Z1931
180Z2024
Material
The nozzle part is made in AISI 316 stainless steel and the housing part in AISI
303 Stainless steel with an outer thread of M13x1. On request also available in
AISI 316.
Strainer
The strainer is 140 mesh based on 90 micron tread and 130*130 micron gabs.
Drop size
The measurements is based on average measurements from different nozzle
inserts:
Pressure
Drop size
< 10 µm
40 bar
0.5 %
Drop size
10 µm –
30 µm
10.5 %
Drop size
30 µm –
50 µm
38 %
Drop size
50 µm –
80 µm
31 %
Drop size
80 µm –
200 µm
20 %
Vertical
1)
reach
20-50
cm
100 bar
2%
30 %
65 %
3%
0%
200-400
cm
1) A longer reach is possible with more Nozzle inserts mounted in a Nozzle Head.
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Power packs
A large range of standard power packs and custom designed power packs are
available with 25, 50 and 200 litre water tank.
The power packs are available as base units or complete including electric control
box as a ready to use unit.
Stationary units available with single and three phase electric motors with IEC or
NEMA connection.
Mobile units are available with combustion engines or DC motors.
Custom designed tanks and units are available in larger quantities.
Benefits:
• Assembled and tested unit ready for use.
• Includes filling and filtration system.
• High reliability.
• Compact design with submerged pumps.
• Long time storage stability.
Technical data 25 litre tank:
Flow range
Adjustable pressure range
1)
Maximum dimensions [W * D * H]
Maximum power capacity
1)
Standard unit excluding control box.
Technical data 50 litre tank:
Flow range
Adjustable pressure range
1)
Maximum dimensions [W * D * H]
Maximum power capacity
1)
4 – 45 l/min
25 – 140 bar
0.85 m * 0.40 m * 0.70 m
7.5 kW / 10 hp
Standard unit excluding control box.
Technical data 200 litre tank:
Flow range [l/min]
Maximum pressure [bar]
1)
Maximum dimensions [W * D * H]
Maximum power capacity (1 el-motor)
Maximum power capacity (2 el-motors)
1)
4 – 30 l/min
25 – 140 bar
0.60 m * 0.30 m * 0.70 m
3 kW / 4 hp
4 – 220 l/min
25 – 140 bar
1.10 m * 0.51 mm * 1.20 mm
30 kW / 40 hp
2 * ( 7.5 kW / 10 hp )
Standard unit excluding control box.
DK - 6430 Nordborg
Denmark
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