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Abu Dhabi Water & Electricity Authority
SPECIFICATION FOR FIELD
INSTRUMENTATION
2 03-02-2009 Flow sensors and metering system revised, Kiosk,
Data logger added1 31-04-2004 Revised to incorporate changes as
marked0 0 2 -0 2 -2 0 0 2 Approved Issuerev. date
Description/issued for prepared authorised
client: ADWEAV ~ - proiect: STANDARD SPECIFICATIONS FOR WATER
WORKS\ title: SPECIFICATION FOR FIELD INSTRUMENTATIONproject phase:
|project: |document: W-l-SS-001 | rev: 2 | sheet: 1 of: 45
Ci^jUuUJ "dSjJLCODE Contracting Co. (L.L.C.)
P.O. Box: 25224-A hu Dhabi
-
1.
GENERAL..............................................................................................................
4
2. APPLICABLE STANDARDS AND
CODES........................................................ 5
2.1 Codes and
Standards................................................................................5
2.2
Units.............................................................................................................7
3. SITE
CONDITIONS................................................................................................7
4. DESIGN CONSIDERATIONS AND FABRICATION
REQUIREMENTS..........8
4.1
General.......................................................................................................8
4.2 Selection of
Equipment.............................................................................
9
5. TECHNICAL REQUIREMENTS (FLOW
INSTRUMENTS)............................. 11
5.1 Electromagnetic Flow Meter
..................................................................11
5.2 Flow Switches............................................
.............................................14
5.3 Flow
Monitors..........................................................................................
14
5.4 Rotary Vane Type Flow
Meter...............................................................
14
5.5 Consumer Water Meter
Devices...............................................................16
5.6 Glass Fibre Required (GRP)
Kiosk.........................................................21
5.7 Battery Powered Electromagnetic Water Meters
................................. 23
5.8 Data Logger
..............................................................................................
26
6. TECHNICAL REQUIREMENTS - PRESSURE
INSTRUMENTS....................29
6.1 Pressure
Gauges.....................................................................................29
6.2 Pressure
Switches...................................................................................31
6.3 Pressure
Transmitters.............................................................................
31
7. TECHNICAL REQUIREMENTS - LEVEL
INSTRUMENTS............................ 33
7.1 Level
Gauges...........................................................................................
33
7.2 Level
Switches.........................................................................................
33
7.3 Level Transmitter - Ultrasonic
Type......................................................34
7.4 Level Transmitter - Hydrostatic Pressure
Type................................... 35
Table of Contents page
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 2
|of: 4 5
[ a a d cSUPPLY DEPT. CODE Contracting Co. (L.L.C.)
Cont. Engineer
FUe No. 123632 P.O. Box: 25224 - Ahu Dhabi
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8. TEMPERATURE
INSTRUMENTS.....................................................................37
8.1 Temperature
Gauges..............................................................................
37
8.2 Temperature
Switches............................................................................
38
8.3 Temperature
Transmitter........................................................................39
9. VIBRATION MONITORING
SYSTEM................................................................42
10. INSPECTION AND
TESTING............................................................................
42
10.1 Pressure
Tests.........................................................................................
42
10.2 Instrument
Calibration.............................................................................
42
10.3 Cable Continuity & Insulation
Resistance............................................. 43
10.4 Loop-Checking and Functional
Testing.................................................43
10.5 Nameplates and
Tagging........................................................................43
10.6
Labelling...................................................................................................43
11. SPARE
PARTS....................................................................................................44
12. SPECIAL TOOLS AND TEST
INSTRUMENTS................................................44
13. PACKING AND
SHIPMENT................................................................................45
14. VENDOR
DOCUMENTATION...........................................................................
45
1Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 3 of:
4 5
AADCSUPPLY DEPT
[contB^ineerCODE Contracting Co. (L.L.C.)
P.O. Box: 25224 - Ahu Dhabi
-
1.
This specification covers a wide category of field instruments
typically used in Water Projects. The specification shall be read
in conjunction with the Instrument Data Sheet which includes the
specific requirements applicable to a project.
The CONTRACTOR shall submit the following documentations:
i) Instrument List - The CONTRACTOR shall prepare a Master
Instrument Index. This list will be used to review CONTRACTOR'S
progress in the selection of instruments and adherence to the
Specification requirements. The list shall contain all instruments,
control valves, solenoid valves and accessories, including items
furnished as part of a package, such as lube oil unit
instrumentation. The Instrument List will also serve a reference
for ADWEA's personnel. Therefore, the list shall be complete in all
respects. A new instrument list shall be issued every two months
throughout the contract period.
ii) Data Sheets - The CONTRACTOR shall complete data sheets
enclosed elsewhere in this contract for all instrument items.
CONTRACTOR shall also furnish calibration sheets and/or calculation
sheets for devices wherever applicable, for example: flow and
pressure elements, control valves, safety valves, etc.
iii) Drawings - CONTRACTOR shall submit drawings, diagrams and
descriptive information for all, the instruments, panel boards and
miscellaneous equipment furnished under this specification with the
requirements for submission of drawings set forth in the project
general technical requirements.
iv) The drawings shall include, but not be limited to the
following:
Outline drawings of all instruments showing dimensions, mounting
provisions, cut-out dimensions, materials, electrical connections,
tag numbers, mode numbers and item numbers. These drawings shall be
provided for instrument and accessory furnished as part of this
Standard.
Steel construction of all panels, control desk, etc.
Log sheets layouts.
GENERAL
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 4 of:
45
AADCSUPPLY DEPT.
Cont. Engineer
File No. 123632
((*(*-0 fl oil
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 - Ahu Dhabi
-
2.1
2. APPLICABLE STANDARDS AND CODES
CODES AND STANDARDS
The CONTRACTOR shall adhere to the Codes and Standards as
applicable from Institutions and Organizations listed below.
Equivalent International Standards are acceptable. CONTRACTOR shall
adhere to the latest editions of all other Codes and Standards of
these organizations, as they may apply.
1) International Electrotechnical Commission (IEC).
2) International Standards Organisation (ISO).
3) Instrument Society of America (ISA).
4) American National Standards Institute, Inc. (ANSI).
5) American Society for Testing and Materials (ASTM).
6) British Standard (BSI).
7) European Norme (EN).
8) Insulated Power Cable Engineering Association (IPCEA).
9) National Electrical Manufacturer's Association (NEMA).
10) National Fire Protection Association (NFPA).
11) Scientific Apparatus Manufacturer's Association (SCMA).
12) American Standard Association (ASA).
13) The Abu Dhabi Transmission and Despatch Company, metering
and data exchange code.
The following list of standards indicate the requirements as
minimum any other standard not listed below or elsewhere in this
tender documents shall be subject to review and approve by the
ADWEA/ENGINEER.
Document No.
IEC 60227
IEC 60331
IEC 60332
IEC 60770
Document Title
Polyvinyl chloride insulated cables of rated voltages
Fire resisting characteristics of electric cables
Tests on electric cables under fire conditions
Methods of evaluating the performance of transmitters for use in
industrial process control systems
5= Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 5 of:
45
j CODE Contracting Co. (L.L.C.)I RO. Box: 2 5 2 2 4 -Abu
Dhabi
-
IEC 61000-4
IEC 60654
IEC 60584
IEC 60751
IEC 60529
IEC 60994
IEC 60625
IEC 60770
IEC 60902
IEC 60534
IEC 60839
ISO 5167
ISO 5168
ISA 5.1
ISO 3511/1
ISO 44
Electromagnetic compatibility for Industrial Process measurement
& Control Equipment (Supersedes IEC 60801).
Operating conditions for Industrial Process Measurement and
Control Equipment.
Part 1: Temperature, humidity and barometric pressure
Part 3: Mechanical influences
Part 4: Corrosive and erosive influences
Thermo couples
Part 1: Reference tables (584/1)
Part 2: Tolerances (584/1)
Industrial Platinum resistance thermometer sensors
Classification of degrees of protection provided by
enclosures
(IP code)
Guide for field measurement of vibrations and pulsations in
hydraulic machines
Interface system for programmable measuring instruments
Methods of evaluating the performance of transmitters for use in
industrial process control systems
Industrial process measurement and control - Terms and
definitions
CV General considerations, sizing, dim. etc.
Alarm and warning systems
Measurement of fluid flow by means of pressure differential
devices
Measurement of fluid flow - Evaluation of uncertainties
Process Instrumentation terminology
Process measurement control functions and instrumentation
symbolic representation
Degree of protection of enclosures
1 *5 Client ADWEA
Y j f e s rProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: documpi^V-|-SS-001 rev: 2 sheet: 6 of:
45
TT eng>o*l!tie No. 123632]
. j ) o ^ L i L a i i ju i,
C O D E Contracting Co. (L.L.C.)
P.O. Box: 25224-A hu Dhabi
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2.2.
ISO 9001
ISO 9002
ISO 9003
ISO 7005/2
UNITS
ISO 4064/1 Measurement of water flow in closed conduits meters
for cold potable water
Quality Control
Quality Control
Quality Control
Instruments Flanges
3.
The instrument ranges and scale calibration shall be in metric
units according to the international system of units (SI), unless
otherwise is indicated on the Instrument Data sheet, as listed
below:
Flow - liquids and vapour m3/hr
gases Nm3/hr Nm3/hr
Volume m3
Pressure barHead mwcLow pressure, draught or low diff.
mmWCPressure Vacuum (1) bar(Low) abs. pressure (2) mm Hg abs.
Temperature C
Conductivity micro S/cmRotating speeds rpmFrequency HzCurrents
AVoltage V
SITE CONDITIONS
1. The site location of this project has a dust laden
atmosphere. The temperature at night drops considerably, resulting
in condensation. These conditions attack instrumentation electric
terminals, contacts, etc. for which the CONTRACTOR must design
protective measures. Any instrumentation not in an air conditioned
atmosphere shall be supplied with waterproof, dust tight
enclosures. In addition, local instrument cabinets shall also be
weatherproof and equipped with space heaters.
2. It is the CONTRACTOR'S responsibility to design, furnish and
install the instruments and control equipment to withstand and
operate properly under the prevailing ambient conditions described
in the project General Technical Requirements of this Contract.
This Specification serves as a guideline to the CONTRACTOR. The
CONTRACTOR shall make recommendations and include all the necessary
equipment or protecting devices based on his previous experience on
similar installations.
I f *Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: |document: W-L-SS-001 rev: 2 sheet: J
of: 45
Cont. EngineerFM No. 123632
( ? .? . j ) C t f j U U U j
CODE Contracting Co. (L.L.C.)P.O. Box: 2 5 224-A bu Dhabi
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3. All transmitters, electric/pneumatic converters, switches and
other electrical devices which provide input signals to control
systems must be housed in waterproof, insulated, dust-tight and
heated (as required) local instrument cabinets to protect against
corrosion, humidity and condensation. Sun shades shall also be
provided and designed to protect cabinets from direct rays of the
sun.
4. Special precautions shall be taken in the selection of
materials and the design of enclosures to prevent failure and
deterioration of mechanical and electrical components due to the
prevailing humidity, high temperature and very corrosive
atmosphere. As a minimum, all equipment mounted in control rooms
shall be suitable for operation at 45C. Field mounted equipment
shall be suitable for operation upto 60C and shall be provided with
sun shields.
The CONTRACTOR shall, where possible, use one instrument
manufacturer of International standing for the supply of all
similar instrumentation included in the Contract and shall obtain
the maximum uniformity of equipment.
a. The equipment shall be constructed to operate accurately and
safely under the operating conditions described or implied in this
standard and the project specifications, without undue strain,
wear, heating, vibration, corrosion or other operating
troubles.
b. All parts shall be made accessible and capable of convenient
removal. Parts subject to wear shall have adequate means of
adjustment and replacement.
c. Parts subject to substantial temperature changes shall be
designed and supported to permit free expansion and contraction
without causing fluid leakage, harmful distortion or
misalignment.
d. The CONTRACTOR shall design all the transmitters, receiving
instruments and electrical control devices to have one (1) standard
signal range. Analogue signals shall be one of
4 DESIGN CONSIDERATIONS AND FABRICATION REQUIREMENTS
4.1 GENERAL
four types:
1) Thermocouples-ISA Type E (chromel - constantan).
2) RTD's-100 ohm Platinum.
3) Electric Control Signals, 4 -2 0 mA.
4) Special volts, 1 -1 0 VDC (only inside control panels).
Digital signals are those used for alarms, indications,
interlocks and controls.
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 8 of:
4 5
(p.p. j ) oV jU L oU
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 - Ahu Dhabi
-
Digital signals shall be one of the following types.
1) Relay & transistor outputs, (OV) or (open circuit) for
zero level and (+V) or (close circuit) for one level.
2) Pulse/Frequency.
a. Conservative electronic design is required. All components
shall be suitable for use at less than 60% rating unless specified
approval for otherwise is obtained, or if the device will not
function at the low values of energy, as in the case with
lights.
3) Where more than one device utilizes the same measurement or
control signal, the transmitter or other signal source shall be
fully equipped to provide all signal requirements. The system shall
be arranged so that failure or any recorder, indicator, control
component, etc. shall not open the signal loop nor cause loss or
malfunction of signal to other devices using the same signal. The
design shall permit removal from service of any indicating or
recording device without upsetting the control systems or requiring
readjustment.
4) All instrument parts (such as Bourdon tubes, pressure
capsules, bellows, etc.) in contact with salt water, shall be
fabricated from Monel or Alloy 20.
5) Dissimilar metals, where galvanic action may occur, shall be
electrically insulated.
6) All pipe threads shall be protected by Teflon tape. (First 3
threads shall be left bare).
7) Locally mounted instruments shall be provided to indicate
pressure, temperature, liquid levels, etc., where necessary for
maintenance, local monitoring and control valve bypass
operation.
8) Embossed or engraved I.D. tags made of Stainless Steel and
clearly showing the instrument identification number shall be
permanently affixed to all instruments.
4.2 SELECTION OF EQUIPMENT
During engineering, the instruments, materials and systems,
shall be properly selected to provide suitable, reliable and fail
safe instrumentation, requiring only a minimum of maintenance;
moreover, the variety in type shall be held to a minimum. Use shall
be made of exclusively new and modern materials suitable for the
intended purpose. The selection of equipment shall be subject to
approval of the ADWEA/ENGINEER.
Sample and documents of selected equipment shall be submitted to
the ADWEA/ENGINEER.
Client ADW EA\p Project: STANDARD SPECIFICATIONS FOR W ATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W -l-SS -001 rev: 2 sheet: 9
of: 45
.O. Box: 25224 - Abu Dhabi
supply DEPT-
Cont. Iitglneer
FHo No. 123632 CODE Contracting Co. (L.L.C.)
-
All instruments shall be suitable for continuous operation at
the ambient temperatures as stated in clause (3.0).
Every precaution shall be taken in the installation of the
instruments to protect them and their electronic components against
the extremely harsh weather condition prevailing in the U.A.E.,
site location. All instruments selected shall be suitable for
tropical conditions and resistant to corrosion.
The electric signals of the electronic control system shall be
as mentioned in the design criteria clause (4.1 - f). The power
supply for the local instruments shall be 24V DC.
Transmitters shall be suitable for field installation, and when
mounted outside - shall be housed in casings to protect them
against direct sun radiation and unauthorized operation.
The process and instrument connections of pressure gauge,
transmitters and switches should be to NPT or BSS standards as
specified in the project data sheets.
Panel mounted instruments shall be suitable for flush
mounting.
Generally indicators shall have dials with white facing and bear
black figures and graduations.
The selection of materials for the wetted parts of instruments,
including equipment such as orifice plates, switch floats, etc.
shall be compatible with the operating conditions.
The selected materials shall ensure a good measurement and be
resistant to corrosion.
The material and rating of the instrument piping shall, in
general, conform to the relevant piping specification. The choice
of other materials shall be considered in special cases.
The process & instrument connections of pressure gauge,
transmitters and switch should be to DIN or BSP standards or Vz NPT
M.
Mercury-containing instruments shall not be used.
Instruments shall have suitably threaded openings to accommodate
the required cable gland.
Glass cover shall be provided on membrane transmitter to avoid
accidental touch to the membrane.
Instruments susceptible to ingress of water shall be of IP-68
grade of protection. All transmitters shall be installed above pump
hall ground level, and shall be IP-67.
Transmitters shall be of the latest technology with
setting/calibration key pad and local digital display.
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 10
of: 4 5
AADCSUPPLY DEPT.
Cont. Engineer
Fite No. 123632CODE Contracting Co. (L.L.C.)
P.O. Box: 25224 -A hu Dhabi
-
5. TECHNICAL REQUIREMENTS (FLOW INSTRUMENTS)
5.1 ELECTROMAGNETIC FLOW METER
5.1.1 GENERAL
The flow meter shall comprise of a flow sensor and a transmitter
unit. The flow sensor and the transmitter shall be supplied either
as an integral unit or shall be remotely mounted from the flow
sensor, subject to ADWEA/ENGINEER approval unless otherwise
specified on the Instrument Datasheet.
The flow meter shall be of the electromagnetic type utilizing
pulsed d.c. excitation and shall be microprocessor based.
The flow meter dimensions shall be in metric units. The flow
meter shall be calibrated at the factory to its actual flow range
in m3/hr as specified in the data sheets. A factory calibration
certificate shall be provided with the meter.
Accuracy shall be equal or better than +0.25% of reading (actual
flow rate) at flow velocity >1 m/s with repeatability within
+0.1% of flow rate. The measurement shall be insensitive to
entrained solid particles.
The flow meter shall have on-site validation capability for
sensor and transmitter. This either comes through built-in feature
within the meters advanced electronics or by a dedicated field
portable validator connected to the meter under test with or
without cable.
The flow meter, which is specified as a settlement flow meter,
shall be supplied according to Abu Dhabi Transmission and Despatch
Company metering & Data exchange code (MDEC).
5.1.2 FLOW SENSOR
The flow sensor tube shall be manufactured from AISI 304, AISI
316 stainless steel or Die cast Aluminium metering with a
non-conductive hard rubber or Neoprene liner to withstand process
temperatures upto 60 C. The liner material shall be abrasive
resistant and approved for potable water use by WRC-UK or
equivalent internationally recognized authority.
There shall be 2 nos. of measuring electrodes with built in
reference electrode. The reference electrode shall ensure potential
equalization between the sensor and the fluid and proper grounding
of the installation. Electrode material shall be SS 316L or
Hastelloy.
Flow meters shall have facility to detect the empty pipe
condition either by additional sensor, flow sensors or other
methods I technologies subject to project specific requirements.
The method shall be elaborated in material submiital for review
& approval by ADWEA / Engineer.
The end connections of the flow tube shall be flanged to ISO
7005-2 PN10/PN16/PN25 as indicated in the data sheet to suit
project piping specifications. The flange material shall be of
stainless steel or carbon steel with Zinc I Aluminium alloy coating
or other material subject to ADWEA approval.
1 = Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 11
of: 45
P AADC!~RliPPL.y DEPTy- Cont. EngineerTpile No. 123632
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 -A im Dhabi
-
The input impedance shall be 1015 ohms or greater so that
electrode fouling does not affect signal and electrode seal
integrity. The sensor data shall be stored in a built-in EPROM
module.
The flow sensor shall be provided with robust powder coated Die
cast Aluminium or Steel housing, certified to IP-68 of IEC 60529
for remote transmitter version only and IP-67 for integral
transmitter version. The manufacturer shall provide necessary type
test certificates for the enclosure. It shall be possible to
validate the instrument on site without removal of the sensor for
ease of fault diagnosis and maintenance.
The electrical connections for cable entry for sensors with
remote transmitters shall be M20 x 1.5 with appropriate cable
glands.
A minimum of ten (10) metres of interconnecting cable between
sensor and the remote transmitter unit shall be included in the
scope of supply of the Bidder. The interconnecting special cable
shall be supplied from the manufacturer of the flow meter and the
length shall be as specified in the project data sheets.
5.1.3 TRANSMITTER UNIT
The transmitter unit shall be either integral with the flow
sensor or remotely mounted to suit the application requirements as
indicated in the project data sheet.
The transmitter unit shall be microprocessor based, of modular
design and shall be easily configurable through integral keypads.
The electronics shall be of modular construction for ease of
maintenance and future expandability.
The transmitter shall be provided with Alpha-numerical
illuminated display for rate of flow and totalized flow indication.
The data storage shall be on EEPROM to preserve data on power
failure without battery backup. The unit shall have high
electromagnetic compatibility according to IEC 801A/DE 0843 and
NAMUR recommendations. The unit shall also withstand an Isolation
Test upto 1800V for 2 sec.
The transmitter shall be housed in a robust Steel or die-cast
aluminium enclosure with IP67 protection for both remote versions
and the integral type.
The unit should have good resistance to shock and vibrations and
withstand acceleration up to 2g/2h per day, 10-100 Hz (complete
system).
The unit shall be provided with extensive self-diagnostics for
operational security with resulting error messages enunciated at
the alarm output.
The transmitter shall power the flow sensor with low frequency
d.c. excitation to provide enhanced zero stability. Routine zeroing
is not acceptable.
The unit shall be able to operate on power supplies in the range
of 85V to 260V AC or 24 V DC.
All inputs and outputs shall be galvanically isolated from the
power supply, the measuring circuit and each other.
1 * 5 ^ Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 12
of: 45
P.O. Box: 25224-A hu Dhahi
AADCSUPPLY DEPT.
Cont. Engineer
Fllo No. 123632
(? (* j )
CODE Contracting Co. (L.L.C.)
-
The following outputs shall be available and configurable by the
user:
i. Analogue, 4-20 mA signal proportional to flow rate or two
independent 4-20 mA analogue signals output for settlement meters
as per TRANSCO metering & data exchange code (MDEC).
ii. Active / Passive (open collector) selectable to
Pulse/Frequency output.
iii. Status configurable for limit values, end value switching,
empty pipe detection, flow direction over ranging or instrument
fault.
The instrument should include provision for upgrading to
Foundation Field bus output standard in the near future as and when
applicable.
The transmitter unit shall be provided with two (2) no's, of
cable glands of size M20 x 1.5 for power supply and signal
cables.
The unit shall have a rangeability of 1000:1 to measure fluid
velocities from 10mm/sec. to 10m/sec. with a specified
accuracy.
The transmitter unit shall be suitable for operation in an
ambient temperature range of 0 to 60 C.
5.1.4 FLOW METER VALIDATION UNIT
A microprocessor based portable field test unit with flow meter
validation software shall be supplied on project request by the
Vendor which will enable to perform Condition monitoring,
calibration and verification of the status of all components of the
flow meter i.e. Sensor, Transmitter and interconnecting cable
including coil, electrodes, insulation, continuity, all outputs,
etc. and storing this data for analysis on a PC/laptop.
The portable field test unit shall be supplied complete with
leather carrying case and all leads, clips and probes necessary to
perform the full range of tests. The unit shall be provided with
its own power supply with re-chargeable batteries and integral
charger unit.
The Electromagnetic flow meter with built-in advanced validation
capability is also acceptable subject to providing the same
extensive diagnostic features found with the dedicated validation
unit.
5.1.5 SPOOL PIECES
For maintenance purposes spool pieces shall be provided of the
same pipeline material coating/lining, each suitable for inserting
into the water main in place of magnetic flow meter. The spool
pieces shall match exactly the face-to-face dimensions of the flow
meter. The number of the spool and requirements is project
specified.
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: |document: W-l-SS-001 rev: 2 sheet: 13
of: 45
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 -A bu Dhabi
-
5.2 FLOW SWITCHES
Flow switches shall be of paddle or vane type with high quality
snap acting hermitically sealed double pole double throw (DPDT)
switch with gold plated contacts rated for 5 Amps at 240V AC.
Flow switches shall be generally used for ON-OFF signal
transmission.
Housing shall be dust and weather tight protected to IP-66 (min)
and materials of wetted parts shall be aluminium bronze alloy,
Monel, 316L SS or similar as specified in the project data
sheets.
Electrical connection shall be M20 x 1.5 with weather proof
cable glands to suit the connecting cable.
Alternative types of flow switches with electronic technology
may also be proposed by Contractor and shall be subject to
ADWEA/ENGINEER approval.
5.3 FLOW MONITORS
Flow monitors shall be of suitable insertion type sensor,
mounted in steel piping using the weld stub supplied with the flow
monitor, the weld stub has a graduated scale to ensure that the
stub can be correctly positioned for mounting. The installation
shall be according to the manufacturer recommendation.
The weld stub shall be stainless steel 316L, for steel piping
shall be A570, the housing shall be aluminium, epoxy power coated,
the sensor sleeve shall be 1.4435/316L with 1.4571/316T; clamp
ring.
The electrodes shall be of stainless steel 1.4435/316L.
Accuracy shall be not less than 2% at flow velocities >1m/s.
Housing shall be dust and weather tight protected to IP-65
(min.)
The flow monitor shall be generally used for ON-OFF signals
transmission through the internal relays; the analogue (4-20 mA)
signal shall indicate the flow rate in the piping. The flow monitor
shall be of electromagnetic type.
5.4 ROTARY VANE TYPE FLOW METER
5.4.1. GENERAL
The meters are to operate with potable water of maximum
temperature of 50 Degrees Centigrade and working pressure up to 16
bar, however, due to occasional surges the maximum pressure may
rise to 20 bar.
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 14 o
cn
_ AADC _ SUPPLY DEPT.
Cont. Engineer
' >j[e No. 123632
(j*.)*. j ) j .Ai
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 - Ahu Dhabi
-
The measuring mechanism of the meter shall be of helical vane
(Woltmann Type) with the axis of vane parallel to the axis of pipe.
The measuring mechanism shall be removable from the meter body with
the body remaining mounted in the pipeline.
The counter (register) shall be dry, and sealed against ingress
of water and dust, with dehumidifying capsule to prevent
condensation. The counter shall be provided with a flap (cover) to
protect against mechanical damage. It should be possible to rotate
the counter against the meter body into at least two different
positions to facilitate read-out.
The measuring mechanism shall drive the counter by a magnetic
coupling. Construction of this magnetic drive should allow for
ancillary equipment (e.g. pulser) to be sandwiched between body and
counter without stopping the flow or depressurizing the pipeline.
The meter shall be preequipped for installation of a pulse
transmitter or encoder at a later date.
The read-out unit shall comprise of one centre sweep pointer and
at least seven (7) digits counter with four (4) black figures (left
hand set) and three (3) red figures (right hand set). Meters shall
be calibrated to read in cubic metres.
All wetted body parts shall be made of materials resistant to
corrosion caused by water from flash distillation desalination
plant. The body shall be made of cast or ductile iron (spheroid
graphite iron, nodular iron) and the measuring mechanism of
stainless steel and high-grade plastics.
The body of the meter shall be of robust construction with the
ability to withstand rough handling, and shall allow for free
standing in horizontal position. The meter shall be adequately
protected against hostile environment i.e. relative humidity upto
100% with condensation, ambient temperature upto 50 Degrees
Centigrade, dust and sand, salt in air and with occasional flooding
by saline water. The body of the meter shall be externally coated
with epoxy paint to 300 microns.
It shall be possible to install the meter in any position
without detrimental effect upon the meter performance.
Each flow meter shall be subject to pressure and leakage test of
1.5 times the nominal pressure before leaving the manufacturers
works.
Each meter shall be accompanied by a manufacturers test
certificate.
The meter shall be provided with flanged end connections. The
flanged connection shall be drilled according to ISO 7005-2, PN 16
unless specified otherwise in the data sheets.
The flow meter shall have an accuracy better than (+2%), in
compliance with the latest ISO standards.
5.4.2 TYPE OF CONSTRUCTION
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER WORKS
r 5 5
Title: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 15
of: 45
[ a a d c[ supply d e p tt Cont. Eoflinoer
-Ite No. 1236321
((*(*-0 < \S jmCODE Contracting Co. (L.L.C.)
P.O. Box: 25224 - Ahu Dhabi
-
All definitions for flow shall apply as per ISO 4064/1 Clause
3.
Nominal flow rates should at least meet the requirements of ISO
4064/1 Table 2.
The accuracy of the meter and its meteorological characteristics
should at least meet the requirements of Class B, ISO 4064/1 Table
5. Preference will be given to the meters that present better
accuracy and better meteorological characteristics than those
required by the standard. Typical Type Test Certificates from
internationally recognised meteorological institute shall be
provided by the Vendor.
Each meter shall have a manufacturers guarantee certificate
giving date of manufacture, specification, quality control approval
(in accordance with ISO 9000) and a three (3) years warranty from
the date of supply.
5.5 CONSUMER WATER METER DEVICES
5.5.1. GENERAL
The following is the general specification for advanced
non-moving parts, static class C, state of the art microprocessor
controlled consumer potable water meter for the distribution
companies exclusively.
This shall cover meters of the following sizes:
1) 15 mm - 1.5 m3/hr.2) 20 mm - 2.5 m3/hr.3) 25 mm - 3.5
m3/hr.4) 40 mm - 10 m3/hr.
The meters shall be designed and constructed for use with
potable water and shall have capability of allowing particles up to
2.5 mm in diameter to pass through. The meter ingress protection
degree shall be according to IP-68.
The flow measuring shall be based on ultrasonic, electromagnetic
or fluidic oscillation technology. The meters shall be powered by a
built-in battery with minimum operating life of 10 years at the
rated environmental temperature.
The meter shall allow 100% overflow and designed for a PN16. The
pressure loss shall be less than 1 Bar (including the non return
valve and the strainer).
The meter shall be tamperproof and not to read any measurements
of air.
5.4.3 PERFORMANCE
1Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 16
of: 4 5
AADCSUPPLY DEPT.
Cont. Engineer
Fite No. 123632
( . f . f . i ) a S j j Zj
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 - Ahu Dhabi
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5.5.3.
5.5.4.
5.5.4.1
BODY CONSTRUCTION
The meter body shall be compact, made from brass or other
approved modern engineering material. The material shall be
approved by WRC-UK or equivalent internationally recognized
authority, a certificate of which shall be submitted for
approval.
The water meter shall be supplied with high quality brass union
type (cap and lining) tailpieces all threaded on major pipe
connections and are to be BSP.
The water meter shall be suitable for fixing in any orientation
(vertical, horizontal or inclined) without loss of accuracy.
A Non-return valve shall be fitted at the outlet end of the
meter. Also a Strainer shall be fitted at the inlet end of the
meter for stopping particulars greater than 2.5 mm in diameter.
Active part of the meter shall be factory sealed. It shall not
be possible to open the meter or replace the battery without
irreparable damage of the tamperproof seals.
SERVICE CONDITIONS
All materials and electronic parts shall be designed in
accordance with relative international standards for use under the
service conditions prevailing at the site. The service conditions
shall be considered as minimum design values.
Ambient Temperatures : 60 CMean in the year : 35 CMinimum
Temperature : 0 CAtmospheric conditions: humid, saline,
corrosive.
GENERAL DESIGN
MAIN FEATURES
Following are the minimum requirements for the meters.
Manufacturer shall propose possible advantages, additional features
and better performance capability for any.
Microprocessor controlled, nonmoving parts measurement of
potable water.
Metrology shall be based on either ultrasonic, Electromagnetic
or Fluidic oscillation technology.
Accuracy - Class 2 to OIML R49 (Class C to ISO 4064)
Working pressure 16 bar.
Digital data output for Remote reading applications.
Provided with Alphanumerical LCD for different readouts.
Volume measure shall be in cubic meter (m3) and flow rate in
(m3/h).
Time stamped events logging.
Meter body shall be Brass to BS EN 12165 or BS EN 12263 or other
advanced engineering material subject to approval.
ADWEASTANDARD SPECIFICATIONS FOR WATER WORKSSPECIFICATION FOR
FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001_____rev: 2 |sheet:
17 of: 4 5
C O D E Contracting Co. (L.L.C.)
P.O. Box: 25224 - Abu Dhabi
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Battery powered with operating life not less than 10 years.
Ingress Protection IP-68 and tamperproof.
5.5.4.2. ALPHA NUMERICAL DISPLAY REQUIREMENTS
The meter shall have an alphanumerical liquid crystal display
(LCD) for multi display purpose.
Digits of display shall be 7 mm minimum height, and be legible
in normal daylight conditions from a distance of two meters by an
observer.
The meter display shall show but not limited to the
following:
Flow rate in m3/h.Accumulated volume m3.Serial number of the
meter Reverse flow Customer number Battery condition Tamper
detection Reverse flowMeter condition (status check).
5.5.4.3. LOCAL COMMUNICATION PORT/TERMINAL
The Meter shall have a port/terminal for local communication
through optical head or induction coupler or any other non contact
means. This communication port/terminal shall be compliant to IEC
61107 requirements.
Optical head/terminal will ensure connection with HHU (Hand Held
Unit) or Laptop/PC. In this regards, for optical head meters shall
have a magnetic ring on the port so that optical head can stands on
it without affecting the proper operation of the meter.
5.5.4.4. REMOTE COMMUNICATION
The Meter shall have Remote Communication facility through the
provision of a cable and socket and plug to connect to data
retrieval device to monitor readings through an Automated Meter
Reading (AMR) system. Other methods of data transfer are also
accepted subject to approval. An open Protocol Architecture is to
be provided for the AMR.
The meter shall be able to communicate at any time (with or
without the need to add any other component) on a remote basis all
stored data through any of communication technologies (PLC, RF,
GSM, GPRS ...). End user shall specify the type of communication
required per batch of meters.
The meter shall be provided with a built-in event recorder for
recording important events and occurrences of not less than 99 time
stamped events. These logs shall include such happenings as
leakage, law battery, malfunctioning, tampering, etc.
Client ADWEAL Project: STANDARD SPECIFICATIONS FOR WATER
WORKS
Title: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 |rev: 2 |sheet: 18
|of: 4 5
(?(* j ) a S j j l , !
CODE Contracting Co. (L.L.C.) jP.O. Box: 25224 -A bu Dhabi i
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5.5.5 NAMEPLATE
The nameplate shall be written on the meter in such a manner as
to prevent removal.Meter number shall also be stored in the
non-volatile memory and shall be part of the data available to AMR
system. Each meter shall bear the following information on the
nameplate:
The End User official LOGO (to be provided).
Manufacturer's name, year & country of manufacture.
Designation of type.
Property of Abu Dhabi Distribution Company o r Al Ain
Distribution Company label.
Serial number (also in barcode format) the serial number shall
be in the following
format XXOODOOOOOO
XX for the shorthand of meter brand name.
00 for the year of manufacture.
D for ADDC or AADC
000000 for a sequential serial number
Unit of measure ( m3 )
Direction of flow
Q3 value.
Maximum admissible pressure (map)
Maximum admissible temperature (mat)
Pressure loss (AP).
The Manufacturer shall submit the nameplate drawing for
approval.
5.5.6 CALIBRATION CERTIFICATE
Each meter shall be accompanied by manufacturer's certificate,
which has traceability to an international laboratory that would be
proposed by the manufacturer and approved by End user. Each meter
shall be attached with a calibration date stamp including the
validity period. Meters shall preferably have prescribed
recertification (Validity) period not less than 10 years approved
by authorized body.
5.5.7 SOFTWARE AND MANUALS
Software for meter parameterisation and remote reading shall
support all standard protocols and inter connectable with other
equipment. This shall be supplied by the meter manufacturer, along
with operation manual of the meter and the software. The
manufacturer shall also provide training on the use of software.The
meter reading software shall provide the data at the receiving end
(PC) compatible with the current major database software.A detailed
manual of the software and its functions shall be provided as a
part of the tender.
1 ^ . Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKS
r "
Title: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: |document: W-l-SS-001 rev: 2 sheet: 19
of: 4 5
j ) J 4 - S jjuj
CODE Contracting Co. (L.L.C.)P.O. Box: 25224-A bu Dhabi
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5.5.8 TEST
5.5.8.1. METER TEST
Each meter shall be subject to routine tests in accordance with
OLML R49 and shall be sealed. A test certificate shall be submitted
in hard and soft copies. The manufacturers seal shall be taken as
proof that the meter has been tested and conforms to the
specification.
5.5.8.2. TYPE TEST
Test certificates, duly approved by an independent authority of
international repute as evidence of successful completion of type
tests described in OLML R49, shall be submitted as part of the
Tender.
5.5.8.3. FACTORY ACCEPTANCE TEST
Within one month from the date of award of contract, the
Supplier shall submit for approval a test and inspection plan to be
conducted at the factory. The costs of factory tests shall be borne
by the Contractor.
No approval of tests or inspection shall relieve the Contractor
of his responsibility to complete the supply according to the
specifications.
A test reports, from fully computerised meter test bench system
for carrying out acceptance tests with error values and curves for
each and every meter of the test sample, shall be provided.
5.5.9 TRAINING
The training is for metering technical staff. Manufacturer shall
provide all training materials required. The venue shall be
selected by the end user Training module shall comprise:
description of the meter parameterisationmeter management /
reading software AMR communications set up Accuracy check fault
diagnosis
5.5.10 DOCUMENTATION AND TECHNICAL MANUALS
The supplier shall submit the Operation and Maintenance
instructions describing in English Language the correct manner of
operation and maintenance of the meters provided under this
Contract with special references to any recently developed
features.
Documentation and technical manuals shall be submitted to end
user two weeks before the Completion of supply.
Documentation and user technical manual shall contain the
following documentation:
Description of the operation of the meter Instructions for meter
configuration and maintenance Complete circuit diagram Component
lay-out drawings
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 2 0
of: 4 5
CODE Contracting Co. (L.L.C.)P.O. Box: 25224 - Abu Dhabi
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The meters shall be packed properly so that no damage is
sustained due to transportation and rough handling during
shipment.All cases shall bear at least the identification mark
relating to the appropriate shipping documents, the contents and
total weight.
Each case or package shall contain a packing list in a
waterproof envelope. All items shall be clearly marked for easy
identification against the packing list.Packing list shall include
meter serial numbers, and should be provided as both soft and hard
copies.The identification mark shall consist of the following
information in sequence and in frame commensurate with the size of
package:
(a) Consignee: ADDC/AADC
(b) Contract nam e: Supply o f
.........................................
5.5.11 PACKING
(c) Contract N o .:
(d) Destination:
(e) Item No., if applicable, package number in sequence and
quantity per package :
(f) Description of contents :
(g) Net and gross weight, cubic measurement:
5.5.12. WARRANTY
5.5.12.1. METER WARRANTY
The meters warranty period shall be 66 months (5 years in
operation plus 6 month in storage)
5.5.12.2. BATTERY WARRANTY
The supplier shall guarantee the battery of the proposed meter
for 10 years under specified environment conditions and
operation.
5.6 G.R.P. KIOSK
The GRP kiosk shall be fixed to a reinforced concrete base and
be divided into two separate water proof compartments. Each
compartment shall have its own door, door handle and lock. It shall
be possible to gain access to either compartment without disturbing
the other compartment. One compartment shall house all cabling and
instrumentation equipment, while the other compartment shall house
a sampling tap and sink mounted on an integral backboard.
1Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 21
of: 45
(?.?. j )
CODE Contracting Co. (L.L.C.)P.O. Box:2 5 224-A bu DJiabi
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The inbuilt pressure transducer of the data logger shall be
connected with the hose/impulse tube that is tapped from the
sampling line that feeds the sample tap, the line shall also have
an isolation valve. The signal cable from the dry side shall be
connected to the data logger, the cable entry shall be through the
separation wall between the dry and wet side. The cable entry shall
be sealed using water resistant sealant.
The drain from the sink shall comprise a 20 mm OD HDPE pipe that
shall pass through the concrete base of the kiosk and terminate in
a 0.05 m3 soakaway situated at least 1 m from the kiosk. The
soakaway shall comprise gravel wrapped in geotextile and be buried
with a minimum cover of 0.3 m.
The GRP material shall be from high quality grade of polyester
resin reinforced with chopped matt glass fibre with approved UV
stabilized gel coat suitable for UAE climate conditions. The kiosk
walls shall be of GRP/12 mm ply board/GRP encapsulated
construction. The doors shall be GRP/12 mm ply board/GRP
encapsulated construction. The ply board used shall be weather and
boil proof to BS 1203. The door shall be fitted with flat gasket to
ensure insulation and prevent water ingress into the kiosk. The GRP
material shall have impact strength of 40 - 50 KJ/m2 to ISO 179-82
and mechanical strength of 80 MPA to ISO/R 527-E6.
The GRP kiosk construction shall be to a minimum of IP 65 with
fire retardant to BS 476 - Part 7 Class 2. The Kiosk construction
shall be such that a thermal insulation of 2.0 to 3.0 W/m2 oC is
achieved. The colour of the GRP kiosk shall be RAL (7032)
All the hardware such as hinges, hooks, nuts and bolts, door
handle and lock shall be of stainless steel grade 304, as shall be
of the sampling tap, sink and integral backboard. Each lock shall
have two (2) keys.
The kiosk shall have small-toughened glass windows for meter
readings and its orientation shall be to the north to minimize
direct sunlight.
The kiosk shall have 2 openings in each compartment, one high
level and one low level to allow for ventilation and drainage. Each
shall be internally covered with a fine stainless steel grade 304
mesh. The openings shall be designed to prevent dust from entering
inside the kiosk. The kiosk shall have full rain canopy.
The kiosk shall be fitted out to house battery powered flow
transmitter with external battery. The kiosk shall be with set of
MCBs rack as required with 20% spares and terminal block rack as
required with 20% spare. The kiosk shall also house space for the
future equipment as shown in the Tender Drawing.
All cables entering the kiosk shall be armoured and installed
using suitable glands. Earthing shall be provided for all
equipments to be installed in the GRP kiosk. Aluminium back plates
for mounting the instruments shall be provided.
1 5 = = ^ Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 22
of: 4 5
CODE Contracting Co. (L.L.C.)P.O. Box: 25224-A hu Dhabi
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The Contractor, while planning for the equipment layout, shall
guarantee the following: -
1. Provide adequate space for ease of maintenance and proper
heat dissipation/ ventilation.
2. Wire trunking shall be neatly laid in a way not to cross over
the equipment and shall be as far as possible to the edge side of
the kiosk. All trunking shall be totally covered.
3. Kiosks shall have earth bar.
5.7 BATTERY POWERED ELECTROMAGNETIC FLOW METER
5.7.1. GENERAL
The meters shall be used for the sector/Bulk consumer measuring
requirement for distribution companies exclusively.
The water meter shall comprise a flow sensor and a transmitter
unit. The flow sensor and the transmitter shall be supplied either
as an integral unit or shall be remotely mounted from the flow
sensor, subject to ADWEA/ENGINEER approval unless otherwise
specified in the Instrument Datasheet.
The water meter shall be of the electromagnetic type utilizing
pulsed d.c. excitation and shall be microprocessor based.
The water meter dimensions shall be in metric units. Each water
meter shall be calibrated at the factory at a minimum of 3 points
between the minimum and permanent flow rates as defined by OIML
R-49. A factory calibration certificate shall be provided with each
meter.
5.7.2. FLOW SENSOR
The flow sensor tube shall be manufactured from AISI 304, AISI
316 stainless steel or Die cast Aluminium metering with a
non-conductive liner. The liner material shall be abrasive
resistant and approved for potable water use by WRC-UK or
equivalent internationally recognized authority.
There shall be 2 nos. measuring electrodes. Unless the
manufacturer can demonstrate that they are not required, there
shall be electrodes or rings which shall ensure potential
equalization between the sensor and the fluid and proper grounding
of the installation. The electrode or ring material shall be SS
316L or Hastelloy.
Water meters shall have an Empty Pipe Detection (EPD)
facility.
The end connections of the flow tube shall be flanged to ISO
7005-2 PN10/PN16/PN25 as indicated in the data sheet to suit
project piping specifications. The flange material shall be of
stainless steel or carbon steel with either a epoxy or zinc /
aluminium coating.
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 23
of: 45
( M . j )
CODE Contracting Co. (L.L.C.) P.O. Box: 25224 -A b o Dhabi
__
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The input impedance shall be 1014 ohms or greater so that
electrode fouling does not affect signal and electrode seal
integrity. The sensor data shall be stored in a built-in EPROM
module.
The flow sensor shall be provided with robust powder coated
housing, certified to IP-68 of IEC 60529. The manufacturer shall
provide necessary type test certificates for the enclosure.
It shall be possible to validate the instrument parameters on
site without removal of the sensor for ease of fault diagnosis and
maintenance.
The electrical connections for cable entry for sensors with
remote transmitters shall be M20 x 1.5 with appropriate cable
glands.
A minimum of ten (10) metres of interconnecting cable between
sensor and the remote transmitter unit shall be included in the
scope of supply of the Bidder. The interconnecting special cable
shall be supplied from the manufacturer of the water meter and the
length shall be as specified in the project data sheets.
5.7.3. TRANSMITTER UNIT
The transmitter unit shall be either integral with the flow
sensor or remotely mounted to suit the application requirements as
indicated in the project data sheet.
The transmitter unit shall be microprocessor based, of modular
design and shall be easily configurable through integral keypads or
through suitable handheld terminal with modern interface method.
The transmitter shall be provided with Alpha-numerical illuminated
display for rate of flow and totalized flow indication. Should only
one value be able to be displayed at a time the unit shall have a
key for scrolling through the information. The data storage shall
be on EEPROM to preserve data on power failure without battery
backup. The unit shall have high electromagnetic compatibility
according to IEC 801A/DE.
The transmitter shall be housed in a robust steel or die-cast
aluminium enclosure with IP68 protection, though IP67 protection
shall be acceptable for the remote type of units housed in a
cubicle above ground. The unit shall be shock and vibration
resistant.
The transmitter shall power the flow sensor with low frequency
D.C. excitation to provide enhanced zero stability.
The unit shall be powered by an external field replaceable
battery with a minimum of 5 years battery life based on 50 ms
sampling period and 15 second sampling frequency at ambient
temperatures of up to 50C. The sample period and frequency shall be
fully programmable such that they can be easily configured by the
operator. The shelf life of the battery must be at least 10 years
at a ambient temperatures of up to 30C.
The water meter shall incorporate a battery management system
that shall provide to information on the current status of the
battery. The system shall provide a battery replacement window of
at least 12 months to ensure that there is no interruption to flow
measurement.
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 24
of: 4 5
( . f . f . j ) ^ j
CODE Contracting Co. (L.L.C.) *P.O. Box: 25224-A bu Dhabi
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If specifically called for in the project data sheet an external
powered meter with battery back up can also be supplied. The water
meter shall be able to operate on D.C. power supply in the range of
12V to 48 V DC with a back up battery that can power the meter for
a period of at least 12 months in the event of power outages.
All inputs and outputs shall be galvanically isolated from the
power supply, the measuring circuit and each other.
The outputs shall be available and configurable by the user.
They shall comprise 2 pulse outputs, one of which shall be
configurable as an alarm output, together with a communication port
for meter configuration and data download.
The transmitter unit shall be provided with sockets or cable
glands of size M20 x 1.5 for power supply and signal cables.
The accuracy of the meter shall comply with the requirements of
OIML R49, accuracy class 1, with a low flow rate (Q1) which shall
equate to a flow velocity in the meter of not higher than 0.1 m/s.
The completed data sheet and supporting documentation shall clearly
list the accuracy class and minimum flow rate (Q1) for each size of
meter. The performance shall be certified by an independent
international certification agency and the measurement shall be
insensitive to entrained solid particles.
The transmitter shall be suitable for operation in an ambient
temperature range of 0 to 60 C.
5.7.4 WATER METER DIAGNOSTICS AND VALIDATION
The unit shall be provided with extensive diagnostics for
operational security with resulting error messages enunciated at
the alarm output.
The operator shall be able to monitor and validate the meter
parameters using either an external field test unit or through
integral software and hardware. The process shall verify the
condition and status of the major system components.
It shall be possible to connect an external unit to the
transmitter through an integrated infrared communication interface
ports and download all the relevant data.
If a portable field test unit is required it shall be supplied
complete with carrying case and all ancillaries necessary to
perform the full range of tests. The unit shall be provided with
its own power supply with re-chargeable batteries and a charger
unit.
5.7.5 SPOOL PIECES
For maintenance purposes spool pieces shall be provided of the
same pipeline material with a suitable coating and lining, each
suitable for inserting into the water main in place of magnetic
water meter. The spool pieces shall match exactly the face-to-face
dimensions of the water meter. The number of the spool pieces of
different sizes shall be project specific.
Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 25
of: 4 5
a a d SL s y p p J ^
CODE Contracting Co. (L.L.C.)I.(). Box: 25224 -A bu Dhabi
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5.8.1 GENERAL
The data logger shall be of compact, rugged, outdoor, battery
operated and GSM enabled capable of operating continuously in harsh
environmental conditions.
The Data logger will be able to log and record the flow signals,
pressure and Alarms and to transmit such data using GSM
communication.
The data logger shall have the capability to operate with long
life battery for at least 5 years
5.8.2 CODES AND STANDARDS
The vendor shall adhere to the codes and standards as applicable
from Institutions and organisations listed below. Equivalent
International Standards are applicable. Vendor shall adhere to the
latest editions of all other codes and standards of this
organisation, as they may apply.
IEC 60654 Operating conditions for Industrial Process
measurement and Control Equipment.
Part 1: Temperature, humidity and barometric pressure
Part 2: Mechanical Influence
Part 3: Corrosive and Erosive Influences
IEC 60529 Classification of degrees of protection provided by
enclosures (IP code)
IEC 60625 Interface systems for programmable measuring
Instruments
CE European Directives on Electromagnetic Compatibility
BS 5515, Section 2 Code of Practice for Documentation of
computer based systems
5.8.3 INPUTS
The data logger shall be supplied as a standard with at least
three inputs, including minimum one channel for the flow
consumption and one for alarm and the inbuilt pressure sensor.
The data logger input circuitry shall be capable of accepting
flow signals, open collector signals from electronic meters. The
data logger shall also be able to accept switch closures or logic
pulses.
5.8.4. SAMPLING RATE
The data logger shall have fast sampling rate. Sampling rate
settings shall be configured different for different channels. The
sampling rate of the data logger shall be at least 1 second.
The logging interval of the data logger shall be configurable
from 1 second to 15 minutes
5.8 DATA LOGGER
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: |document: W-l-SS-001 rev: 2 sheet: 26
of: 4 5
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5.8.5. MEMORY
The memory of the data logger shall be non-volatile or battery
backed so that data is not lost as a result of main battery
replacement. The memory capacity shall be expandable.
The memory of the data logger shall be sufficient for storing
approximately two months of data recorded at a 15-minute interval
from one channel also considering the Alarm and event that could
occur.
5.8.6. ALARMS
The data logger shall include real time features such as
monitors and alarms. In addition to sending data at a selected
frequency and time, the data logger shall be able to transmit
information if alarm condition occurs.
The data logger will transmit the alarm which are configurable,
the following but not limited, alarm shall available
Low Battery Alarm for Battery powered Flow meter
Low Battery Alarm for Data logger
Low and High Flow
Low and High Pressure
Forward/Reverse Flow status
5.8.7. INTERNAL CLOCK
The data logger shall contain 24-hour real time clock with date
facility. The accuracy of the data logger internal clock shall be
better than one minute at all times. This can be achieved by the
electronics of the data logger or by synchronising its clock using
the GSM network
5.8.8. FUNCTIONAL SPECIFICATION
The data logger shall feature the facility for a number of
specific information and project requirement to be programmed. The
data logger shall be able to record flow/consumption profile using
pulse count recording.
Project specific information to be programmed into the logger
shall include but not limited to:
Project and Data centre detail.
Scale factors and offsets for each input
Units and formats for measurements
Channels and memory to be allocated for each channel
Alarm and event configuration
Frequency of data transmission
Frequency of data logging
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 27
of: 4 5
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5.8.9. BATTERY
The data logger shall have internal battery and the battery
shall be field replaceable in a workshop without having to be
returned to the manufacturer.
The unit shall be powered by field replaceable internal battery
with a minimum of 5 years battery life at a 15 minute logging
interval and transmission of data once daily at ambient
temperatures of up to 50C. The shelf life of the battery must be at
least 10 years at an ambient temperature of up to 30C.
If specifically called in the project specification, mains
powered data logger can also be supplied. The shelf life of the
back up battery must be at least 10 years at an ambient temperature
of up to30C.
5.8.10. GSM
The data logger shall have the GSM communication facility. The
GSM modem shall be internal and the GSM antenna shall be integral
to the data logger. If required, the unit shall also have the
option to connect to an external antenna.
The data logger shall incorporate a GSM modem for the purpose of
transmitting and receiving data to and from the network. The GSM
modem shall be capable of transmitting and receiving instructions
from a central data server using the short message services (SMS)
or general packet radio service (GPRS)
The GSM modem shall be capable of operating at frequencies of
900 MHZ and 1800 MHZ and compatible with the GSM service providers
in United Arab Emirate (ETISALAT and DU)
The data logger shall permit the replacement of the SIM card by
the user. It shall support all current forms of SIM cards in common
use by GSM operators in United Arab Emirate (ETISALAT and DU)
The data logger can be programmed to initiate data transmission
hourly, daily, or weekly at a user-selected time. In the event that
the networks reject the SMS or GPRS connection, the data logger
will proceed through a retry algorithm.
5.8.11. COMMUNICATION PORT
The data from the data logger shall be retrieved by download
data via an RS 232 or with a Universal Serial Bus or with an
Ethernet link to a Laptop PC, PDA or any other link.
5.8.12. HAND HELD DEVICE
Portable Hand held data collection unit shall be provided for
downloading the data from the data logger and download it to the
PC/Laptop available in the data centre.
The data collection unit shall be supplied with power supply
with recharchable batteries and integral charger. The unit shall
also have the required communication port and cable with connector
(USB / Infrared / serial port) compatible with the data logger and
the central data centre system.
i s Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 28
of: 4 5
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5.8.13. CONFIGURATION DEVICE
Portable Hand held programming unit shall be provided for
configuration and settings of input output channels, configuring
alarm and event. The data collection unit shall be supplied with
power supply with researchable batteries and integral charger.
5.8.14. SOFTWARE
The data loggers shall be able to communicate with PC to store
and analysis data.
The data logger analysis software shall be provided free of cost
and should provide trending facility and report generating
facility. Retrieved data from the data loggers shall be translated
to Microsoft Excel schedule and graph showing recorded data time
and date.
5.8.15. PHYSICAL PROPERTIES
The data loggers shall be of compact, rugged, outdoor and
battery operated instrument capable of operating continuously in
harsh environmental conditions.
The data logger shall be completely waterproof, sealed and
pressure tested (IP 68) and battery powered and requires no
maintenance for at least five years.
The SIM card should be field replaceable.
The data logger shall be able to attach to a panel or bolt onto
a chasis or rack mounted and fit inside enclosures. All the fitting
and mounting accessories shall be provided with the set.
The data logger shall be able to withstand an ambient
temperature of 0C to 60C.
6. TECHNICAL REQUIREMENTS - PRESSURE INSTRUMENTS
6.1 PRESSURE GAUGES
6.1.1. GENERAL
The gauges shall be circular dial industrial type and of the
safety pattern design.
The pressure gauges shall be of 'BOURDON TUBE type with
concentric scale in accordance with BS 1780 and additional
requirements specified below.
6.1.2. CASE
The gauges shall be suitable for direct mounting.
The nominal size shall be 150 mm.
The range shall be as per data sheet. While selecting the
maximum range it should be ensured that the normal operating
pressure is at approximately 60% of the range.
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 29
of: 4 5
( f . j v j ) < \S \ j j j j .
CODE Contracting Co. (L.L.C.) ). ,U ) ' Huv: 25224 - Ahu D habi
I
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The case material including blow-out plate shall be stainless
steel. A full blow-out device shall be fitted to the back of the
pressure gauge case, to prevent the pressure in the gauge from
exceeding 0.3 bar g (30KPa) in case of tube rupture.
The blow-out back plate shall be provided with a flexible
compensation facility and sealing ring, both made of a hydrocarbon
resistant synthetic rubber.
The window shall be of shatterproof glass.
The case shall be suitable for liquid filling according to
IEC-60529, IP-65 protection.
The case shall be glycerine (glycerol) filled if the pressure
gauge installation is susceptible to vibration.
6.1.3 PRESSURE SENSING ELEMENT
The pressure sensing element shall be of minimum AISI 316 SS
Bourdon tube welded to AISI 316 shank and tube end piece. Both
welds shall be full argon-arc welds (TIG wildings) and shall be
made with the use of AISI consumables. The Bourdon tube shall be
placed at least 7 mm inside the shank.
6.1.4 CONNECTION
The gauges shall have a bottom connection as specified.
Connection size shall preferably be 1/ 2
inch NPT (M).
6.1.5. POINTER MOVEMENT
The movement shall be of corrosion and wear-resisting material
e.g. stainless steel.
6.1.6. POINTER AND DIAL
A stainless steel flexible pointer stop on the dial shall be
provided.
6.1.7. SAFETY FACTOR
Pressure containing parts shall be designed with a safety factor
of 4 to 1.
6.1.8. ACCURACY
Accuracy of the gauge shall be better than +1 % of f.s.d.
1 % Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: |document: W-l-SS-001 rev: 2 sheet: 30
of: 45
CODE C o n tra c t in g Co. (L.L.C.)P.O. Box: 2 5 2 2 4 - A b u
Dhabi
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Each gauge shall be supplied with a gauge cock and a sample cock
which shall be fitted between the gauge and the discharge pipe
according to the approved primary connection diagram. Also a
pulsation damper / snubbers shall be supplied with each gauge if
mounted in highly pulsating process.
6.2 PRESSURE SWITCHES
The pressure-sensing element may be of the Bourbon tube, spiral,
helical, bellows or diaphragm type, depending upon the application
requirements. The pressure sensing element shall be of AISI 316 SS.
Pressure switches shall withstand the maximum pressure of the
system to which it is connected. In addition, over range
protection, (at least 1.3 times the maximum scale reading), shall
be included for all instruments. Gauge protectors shall be included
wherever required to withstand maximum surge pressure. The Vendor
shall indicate the proof pressure for the quoted model in his
offer.
Set point for pressure switches shall be adjustable throughout
the operating range.
Pressure switches shall have V2" NPT (F) process connection.
Pressure switches generally be used for "ON-OFF" applications
with an adjustable set point and a differential gap with a
reference or calibrated scale. The switch type shall be snap action
DPDT, rated for 5 amps at 240V AC or 1 amp at 30V d.c. The switch
shall also be hermetically sealed with gold plated contacts. Degree
of protection shall be NEMA type 4X, IP-65 or better.
6.3 PRESSURE TRANSMITTERS
Pressure transmitters shall be of the direct sensing type with
the sensing element as per manufacturer's standard. The diaphragm
shall be hermetically welded to the measuring element assembly,
which shall be suitable for the operating temperature limits of 0
to 60 C unless
otherwise specified.
The transmitter shall be of a smart type with modular design and
capacitive sensor. The measuring element shall be able to withstand
a temporary/permanent overpressure to at least 33% of the specified
range limits without calibration shift.
All wetted parts and the diaphragm shall be compatible with the
process fluid and shall be of minimum AISI 316 or ceramic. The
measuring assembly fill fluid shall be silicon oil, unless
otherwise specified and non-toxic certificate shall be provided for
filling fluid. Alternatively dry capacitance sensor shall also be
acceptable.
PTTE gaskets shall be applied as a standard, unless otherwise
specified. The bolts and nuts shall be high tensile stainless steel
ASTM A564 - T630 - H1150 unless otherwise specified.
The transmitter enclosure class shall be according to IP-67 of
IEC 60529, as a minimum.
6.1.9. ACCESSORIES
| 5S>... Client ADWEAProject: STANDARD SPECIFICATIONS FOR
WATER WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 31
of: 45
(?(* j ) Js $ S ~ c\ S j JL
I Contracting Co. (L.L.C.)LO. Box: 25224 - Abu Dhabi
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The process connection shall be V2" NPT (M) and the electrical
signal cable entry connection
shall be M20 x 1.5 metric, unless otherwise specified in the
data sheet. Unused electrical connections shall be plugged off with
a recessed head screw in compliance with the specified electrical
safety requirements. The screw material shall be of stainless steel
for stainless steel enclosures. The signal cable termination points
shall of the screw type.
The transmitter output signal shall be 4-20 mA with hart
protocol as specified in the data sheets.
The transmitter power supply voltage shall be 24 VDC, for
two-wire transmission system with a minimum power supply voltage of
12.5 VDC.
The transmitter electronics shall be microprocessor based.
Printed circuit board(s) should be of replaceable modular
construction, shall be hermetically sealed or protected by a
corrosion- resistant coating (tropicalized) and vibration-free
supported in case of plug-in type circuit boards.
Signal wiring terminals and electronics shall be housed in
separate compartments, so that the electronics remained sealed
during electrical connection of the transmitter to the signal
cable.
The electronics system shall be provided with a reverse polarity
protection circuit.
Zero and span shall be non-interacting, easily and continuously
accessible. The external adjustment(s) should be provided with an
environmental protection cover. It shall be possible to calibrate
the transmitter locally through dedicated push buttons for zero and
span with digital accuracy.
The transmitter shall be provided with integral digital
indicator with scale identical to the calibrated range as indicated
in the instrument data sheet.
The performance of the transmitter shall be as follows:
The transmitter accuracy including combined effect of linearity,
hysteresis and repeatability shall be equal to or better than 0.1%
of calibrated span.
The dead band shall be equal to or better than 0.05% of
span.
Stability (not including temperature or pressure effect) shall
be better than 0.1% of the minimum span per 30 days or 0.2% of URL
for one year.
The total dynamic effect of the temperature including span and
zero error:
At maximum span - equal or less than 1.5% of the span
At minimum span - equal or less than 4.5% of the span, unless
otherwise specified.
The total effect of the radio frequency interference's shall be
equal or less than 0.1% of the output span, with the transmitter
enclosure cover in place. The transmitter shall be provided with
EMI/RFI integral transient protection also when the cover has been
removed. The protection level shall be as per NAMUR recommendations
and EMC directive compliance.
| 5^.. Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 32
of: 4 5
CODE Contracting Co. (L.L.C.) j25224 - A!)U Uhabi j
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6.3.1 ACCESSORIES
One no. of hand held portable configurator shall be included in
the scope of supply of the vendor as an optional item if
specified.
7. TECHNICAL REQUIREMENTS - LEVEL INSTRUMENTS
7.1 LEVEL GAUGES
Local level gauges for the surge vessels and reservoirs shall be
of the direct reading magnetic type where a permanent magnet
mounted in a float drives a series of flaps. A small permanent
magnet shall be attached to each flap to ensure that the flaps
remain in a given position even when severe vibration occurs. The
float shall be concentric magnetic design with unsupported sections
to provide a strong and uniform magnetic field. The external
mounted float guiding tube / chamber shall be of 304 SS and the
float shall be AISI 316 SS. The housing of the flaps shall be dust
and watertight. A graduated scale made of stainless steel with 1 cm
division shall be fixed adjacent to the float guiding
tube/chamber.
Only one (1) level gauge shall preferably be used on a vessel.
If, however, two (2) or more level gauges are required, they shall
be installed in such a way that the visible lengths overlap by at
least 100 mm.
The level gauges can be fitted with field adjustable snap acting
micro switches for high and low level alarms. The alarm contacts
shall be gold plated and rated for 5 amps at 240 V AC. The switch
enclosure shall be weather proof to NEMA-4 or IP-65. Electrical
connections shall be M20 x 1.5 with cable glands.
7.2 LEVEL SWITCHES
Level switches shall be Ultrasonic type, float or displacer
operated and shall have high quality snap-acting double pole double
throw micro switch type.
Level switches shall be of packless construction; there shall be
minimum moving parts in the liquid. The float and sleeve shall be
made of 316 SS and mounted inside a flanged external cage / float
chamber. The float chamber shall be provided with side / side
flanged connection of size 2 inch ANSI 150 lbs RF.
Alternatively horizontal float type magnetic switches will be
considered according to the service conditions.
Housings shall be weatherproof to IP-67. Body materials shall be
aluminium bronze alloy. Wetted parts shall be 316 SS / Monel or
similar approved.
The switching element shall be hermetically sealed snap acting
micro switch rated for 5 amps at 240 V AC with gold plated
contacts. Each switch shall be provided with DPDT contact
arrangements. The switch enclosure shall be weather proof to IP-67
of IEC 60529. Cable entry shall be M20 x 1.5.
i : Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 3 3
of: 45
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7.3 LEVEL TRANSMITTER - ULTRASONIC TYPE
The level sensor shall operate on the Ultrasonic principle. The
unit shall comprise of a sensor and a field mounted Transmitter
unit, interconnecting cable and accessories such as sensor flanges,
mounting frame, alignment unit and protective cover as required for
a complete installation.
7.3.1 SENSOR
The sensor shall be suitable for a measuring range as per the
process data sheet.
The probe shall be provided with a built-in temperature sensor
for the compensation of sound velocity.
The sensor shall be flange mounted on top of the storage tank
and supplied with a mounting flange or threaded. For easy mounting
and accurate positioning of the sensor an alignment unit shall also
be supplied, if required by the application (i.e. when process
connection is threaded).
The sensor housing shall be of polypropylene (PP) and shall be
certified to IP-68 enclosure class.
The sensor shall operate satisfactorily under ambient and
operating temperature limits of 0 C to 60 C, a relative humidity of
0 to 100% RH. and maximum operating pressure of 2 Bars
(absolute).
The following accessories shall be supplied with the sensor
unit:-
i. All weather Protective Cover
ii. Interconnecting cable between the censor and transmitter,
(as required by the application). The cable shall be supplied from
the manufacturer of the instrument.
7.3.2 TRANSMITTER
The transmitter unit shall be of single channel version suitable
for field mounting compatible with the Ultrasonic Level Sensor on
the storage tanks.
The unit shall be microprocessor based and of modular
construction. The operation shall be based on intelligent software
using fuzzy logic for echo analysis and rejection of sporadic
reflections, interference echoes and multiple reflections.
The transmitter enclosure shall be certified to IP-67 of
IEC-60529.
The unit shall be provided with a keypad on the front panel to
be used for configuration purposes together with an illuminated LCD
display and bar graph segment display for level in steps of 10% or
better.
Configurations shall be carried out by the use of standard
operating matrix and the time required for starting minimized by
the use of pre-set operating parameter values. Data storage shall
be in EEPROM non-volatile memory to avoid requirement of battery
back up. A keypad locking facility to prevent unauthorised access
to program changes shall be provided.
1 *3Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 34
of: 45
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7.4
7.4.1
7.4.2
7.4.3
The unit shall be suitable for operation in a temperature range
of 0 to 60 C with 95% average RH.
The transmitter shall provide a 4-20 mA analogue signal output,
linearly proportional to the level in the tank, and three (3)
independent SPDT relay outputs, each with one potential free
changeover contact. The output shall be programmable through the
keypad and the input, outputs and power supply shall be
electrically isolated from one another. One fault alarm contact
shall also be provided with LED indication.
The unit shall operate on a power supply of 24 V DC or 240 V
AC.
The measuring uncertainty shall be within 0.2% for maximum
measuring span.
A 2 inch mounting post of galvanized steel along with mounting
screws and nuts and an aluminium all-weather cover for the
protective housing shall be supplied with each transmitter.
LEVEL TRANSMITTER - HYDROSTATIC PRESSURE TYPE
GENERAL
The transmitter shall comprise a hydrostatic pressure sensor
suitable either for mounting on a flanged connection located in the
water reservoir or for insertion through a borehole into water well
by means of a connecting cable. This specification is based on the
latter application, which requires the most stringent features. The
flanged type shall generally follow the same specification except
for the enclosure class that may be relaxed to IP-67.
DESIGN FEATURES
The hydrostatic pressure sensor shall comprise a measuring cell
mounted in a stainless steel probe tube fitted with a stainless
steel diaphragm. The diaphragm shall be protected by a fine mesh
metal grid and a protective cover. The probe tube shall be filled
with silicon oil which shall transmit the hydrostatic pressure of
the liquid column to deflect a silicon diaphragm with a thin film
strain gauge. CONTRACTOR shall provide non-toxic certificate for
the filling fluid. Variations in pressure on the surface of the
liquid shall be compensated by an air tube passing through the
connecting cable to the other side of the silicon diaphragm. The
transducer should have an over pressure rating of at least 4 times
nominal pressure. A durable conical cable sealing shall be fitted
on the probe tube with a moisture barrier on the pressure
compensation line for long term stability. In case of failure the
sensing module shall be replaceable.
MATERIALS
(i)
(ii)(iii)
(iv)
Sensor Tube
Diaphragm
Gasket
Cable
AISI 316L Stainless Steel
AISI 304 Stainless Steel
Viton
Polyethylene insulated and bound with steel webbing
1 1Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: document: W-l-SS-001 rev: 2 sheet: 35
of: 4 5
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CODE Contracting Co. (L.L.C )J W - B o x : 2 5 2 2 4 - a bu
Dhabi
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7.4.4
7.4.5
7.4.6
7.4.7
7.4.8
7.4.9
MOUNTING
The probe and cable shall be mounted by galvanised steel pressed
clamps cable holder including connection box or a housing with a
1.5 inch (nominal) threaded connection. The diameter of the sensor
shall be less than 30 mm to facilitate easy insertion and
withdrawal from the guide tube.
ENCLOSURE CLASS
The cable probe shall be certified for IP-68 and
housing/connection box to a mini, of IP-65.
The probe shall be suitable for operation up to a process
temperature of 60 C.
ELECTRONIC MODULE
The electronics shall be microprocessor based and completely
potted with compound to protect them from moisture damage. The unit
shall provide a 4-20mA two wire signal output linearly proportional
to level change. The 24V DC power supply shall be provided by the
connected RTU of the system SCADA. The change in output shall be
insignificant for terminal voltage variations from 12 to 30 V DC
and for a load resistance of 0 to 800 ohms. The sensor shall be
provided with integral over-voltage protection of at least 10 kV to
prevent short transient voltage peaks from damaging the electronics
unit. The unit shall have an electromagnetic compatibility of 10
V/m. Zero and span adjustment shall be possible digitally through
push buttons on the enclosure.
MEASURING RANGE
The unit shall have a measuring range as specified in the data
sheet.
PERFORMANCE REQUIREMENTS
Accuracy :
Repeatability :
Hysteresis :
Minimum Overpressure resistance :
0.25% of full scale (sum total of linearity,
(hysteresis and repeatability).
0.1% of full scale
0.1% of full scale
10 times
INSTALLATION ACCESSORIES
Two (2) inch diameter (nominal) stilling well or guide pipe.
1 Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER
WORKSTitle: SPECIFICATION FOR FIELD INSTRUMENTATION
Project phase: project: documeQt=.v