Transcript leak detection equipments

Water leak detection at LHCb
Detection of cooling water leaks below electronic racks
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Counting House
Three levels
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Slight slope towards one side
JMB-29-09-2004
UX85-SALLE DE COMPTAGE
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Lowest point
of the barrack
Sensor cable
Sensor cable
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Leak Detection
The sensing cable has two insulated wires and two conductive polymer coated
electrodes. A small DC voltage (5-9 volts) is applied to the sensing cable, and
internal resistors limit the current flow through the sensor cable loops to
approximately 75 microamps. The actual amount of current flowing is
monitored by measuring the voltage drop (V1) across an internal reference
resistor. If a spill occurs, additional current will seek the path of least
resistance and flow across the leak. This results in increased current flow
through the reference resistor. The resultant increased voltage drop across
the reference resistor signals the module to turn on the alarm.
Continuity Monitoring
If the cable is broken, no current will flow in the loop. The voltage across the
reference resistor decreases to zero and the internal circuitry recognizes this
as a continuity fault.
Leak Location
After a leak has been detected, the circuitry in the module is automatically
reconfigured into the locating mode. The digital readout of the location is
generated by measuring the voltage drop along the sensing cable between the
leak and the module. The voltage drop is linear and proportional to the leak
location. A different scaling factor is applied for feet, meters, or zones.
Leak detection is accomplished by monitoring the
voltage across an internal reference resistor.
Leak location is determined by measuring voltage
drop along the cable from the module to the leak.
07 October ‘04
JCOV
R. Lindner
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Basic System
With its internal alarm relay and front panel LED status
indicators, the TTSIM-1A can be used as a stand-alone
leak detection alarm or it can be connected to TraceTek
SIM network, Distributed Control System or Building
Management System
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Locating system
The leak detection event is logged to an event history file
and all status and event information is made available via
RS232/RS485 MODBUS to any host PLC or plant or
building automation sys-tem.
R. Lindner
TT-NRM Network Relay Module
Description
The TraceTek® TT-NRM Network Relay Module provides the
capability to add up to 320 individual alarm relays to a TraceTek
TTDM-128 / TTSIM leak detection network. The TT-NRM
communicates with the TTDM-PLUS/128 via the same RS-485
network used for TTSIMs. The TT-NRM can be installed in a wide
variety of configurations, allowing many leak detection system
layout possibilities.
Expandable
The TT-NRM is supplied as a base unit (with power supply,
communications interface, DIN rail and end blocks) and separate
relay modules. Each relay module contains 2 independently
addressable relays. Up to 16 relay modules can be installed on
each base unit, and up to 10 base units can be connected to a
single TTDM-PLUS. The leak detection network can be expanded
at any time with minimal effort.
07 October ‘04
JCOV
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Electronic Racks
Counting house
1 2 3 4 5
Calorimeter
TTDM-128
20
18
21
19
TTSIM-1A-230
TTSIM-1A-230
TTSIM-1A-230
6 7 8 9 10
11 12 1314 15
16
Muon
Detector
17
Muon
TT-NRM-BASE
11xTT-NRM-2RO
DSS
shielding wall
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Product characteristics
Cable diameter 0.24 in. (6.0 mm) nominal
Cable diameter with connecter 0.52 in. (13 mm) nominal
Continuity and signal wires 2 x 26 AWG with insulation of fluoropolymer
Sensing wires 2 x 30 AWG with jacket of conductive fluoropolymer
Carrier Fluoropolymer
Cable weight (50-ft length) 2.3 lb
Technical Information
Breaking strength 160 lb
Cut-through force >50 lb with 0.005 in. blade;
crosshead speed 0.2 inch/minute
Abrasion resistance >65 cycles per UL 719
Maximum continuous
operating temperature Sensing cable: 194°F (90°C)
Cable connectors: 185°F (85°C)
Chemical resistance
Cable functions normally after Trichloroethylene (100%)
exposure in accordance with Sulphuric acid (98%)
ASTM D 543 at 77°F (25°C) Hydrochloric acid (37%)
for seven days: Hexane (100%)
Methanol (100%)
Sodium hydroxide (10%)
Xylene (100%)
Aqua regia
Note: Prolonged exposure to concentrated ketones may cause temporary reduction of sensitivity; consult factory.
Radiation resistance
Cumulative radiation exposure of 10 megarad gamma radiation over design life of 30 years.
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TT3000
TraceTek Sensing Cable for Conductive Liquids TraceTek TT3000 sensing cable detects the presence of conductive
liquids at any point along its length. Most acids and bases and even deionized water can be sensed and located. Installed
with a TraceTek alarm and locating module, the cable senses the presence of fluid, triggers an alarm, and pinpoints the
location.
Distributed sensing
TT3000 sensing cable provides distributed leak detection and location over a wide range of areas. The cable is availablein
a variety of lengths to provide as much coverage as needed.
Design flexibility
TT3000 sensing cable is available with factory-installed metal connectors that plug together. The measurement circuit is
not dependent upon the conductivity of the leaking fluid. Therefore, the same cable will detect a wide range of fluids
without special design considerations or calibration.
The cable is designed for a variety of applications, including floor surfaces, subfloors,equipment locations, pipes, storage
tanks, and trenches. The cable is small, lightweight, and flexible, allowing easy installation. The smooth design allows
quick drying.
Advanced technology
Raychem’s conductive-polymer technology and fluoropolymer construction make TT3000 sensing cable mechanically
strong and chemically resistant. The cable is constructed of two sensing wires, an alarm signal wire, and a continuity wire
embedded in a fluoropolymer carrier rod. This rugged construction exposes no metal, and enables the cable to be
reusable even in corrosive environments.
07 October ‘04
JCOV
R. Lindner