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8/10/2019 Water Supply Project Specification
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TECHNICAL SPECIFICATIONS
SECTION 6
WATER SUPPLY SYSTEM
6.1 General
These Specifications shall be applied on all water supply system
works, comprising, but not limited to, the water intake structure,
conveyance pipeline, transmission pipeline to the elevated tank, water
elevated tank and distribution network pipeline which shall consist of
various works that are grouped according to their natures and
characters as set out below :
(a) Civil works including earthwork, concrete works, drainage
works, roadway works, outdoor works and others;
(b) Piping works, for the conveyance, transmission and
distribution network pipelines including valves; and
(c) Architectural and metal works including fencing and gate
setting, ladders, anchoring and others.
6.2 Civil Works
6.2.1 Earthworks
The working area shall be confined within the lots demarcated
as shown on the Drawings. The areas shall be cleared, stripped
and leveled to the lines, grades, formations and dimensions as
shown on the Drawings.
The earthworks shall be undertaken and completed for, but not
be limited to, the following :
(a) Trench excavation, bedding and backfilling along the
alignment of the treated water transmission pipeline and
the treated water distribution network pipelines ;
(b) The lot assigned to the elevated water tank;
(c) Preparation for structural foundations of the various
concrete structures;
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(d)Sub-grading for roadways including associated subsidiary
drainage works and flooring of open space in the lots to be
occupied by the elevated tank ; and
(e) Other miscellaneous and ancillary works.
Each work item shall be governed by the respective relevant
provisions of the Technical Specifications, such as :
(a) Open excavation works including pits and trenches
(b) Cobble or broken stone bedding
(c) Sand bedding
(d)Earth or sand backfill works
6.2.2 Concrete Works
Concrete works shall include the following items :
(a) Lean concrete works employing K125 bedding
materials of concrete structures ;
(b) Concrete foundations, footings, blocks, saddles, posts,
etc. to be required for pipes;
(c) Structural concrete works using K225 for water tower
to store treated water; and;
(d)Concrete K250 works for block-out and secondary
concrete to be made for anchoring the equipment,
devices and materials.
All the concrete works shall be executed and completed
conforming to the lines, grades and dimensions as shown on the
Drawings and shall be carried out under the respective relevant
provisions of the Technical Specifications, such as :
(a) Lean concrete works
(b) Structural concrete works
(c) Block-out and second stage concrete works
The Contractor shall be checked the necessity of thrust concrete
block at steel pipe bending points or tee setting points, and
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concrete block, which has required volume, shall be placed if
necessary. All cost incurred for this work shall be included in
the lump sum price for the relevant items in the Bill of
Quantities.
6.2.3 Drainage Works
Drainage works to be undertaken within the premises of the lot
for the facilities shall include side drain ditches which are to be
placed at the side of the roadways as shown on the Drawings.
The drainage works shall also include drainage system to drain
surface water out of the lot to a drainage outfall.
The drainage facilities provided within the premises of the lot of
facilities shall be executed and completed to the lines, gradesand dimensions as shown on the Drawings. Each work item
shall be carried out in accordance with the respective relevant
provisions of the Technical Specifications.
6.2.4 Roadway Works
Paved roadways shall be installed within the premises of the lot
of the facilities. The base course and the roadway pavement are
designed for lighter traffic only and are therefore narrower inwidth and thinner in sections than the normal roads. The
roadways shall be provided with crushed stone and side drain
ditch. All works shall be completed according to the lines,
grades and dimensions as shown on the Drawings and shall
comply with the respective relevant provisions of the Technical
Specifications for the following items :
(a) Sub-grade
(b) Side drain ditches(c) Shoulder
(d)Sodding
6.2.5 Outdoor Works
Outdoor works shall include all structures and facilities to be
constructed within the different lots of the water supply system
complex. The work items are as set out below :
(a) Fencing and gate setting
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(b) Sodding and tree planting on open spaces of the lot
All the above works shall be completed to the lines, grades and
dimensions as shown on the Drawings, and shall include,
except the metal works such as fabrication of fences and gates,the following :
(a) Excavation of pits, trenches for fences, gates, side
drain and ditches
(b) Wet masonry work for side drain ditches
6.3 Mechanical Works
6.3.1 General
Mechanical works for the water supply system shall consist of
erection, installation, fabrication and assembly of the equipment
and materials provided for this system. The works shall be
executed and completed to the lines, positions, places and
dimensions as shown on the Drawings.
All the works shall be carried out by the Contractor until the
system has been certified by the Engineer as fully and
satisfactorily completed and have passed all requiredperformance tests, whereupon the Contractor shall be issued
"Mechanical Completion" and "Performance Test" certificates.
The equipment and materials to be incorporated in the water
supply system include, but shall not be limited to, the
following :
(a) Pipelines for transmission and distribution of treated water
including fittings and valves
(b) Elevated water tank
6.3.2 Standards and Workmanship
All materials shall be new, the best of their respective kinds and
of such quality as are usual and suitable for work of like
character. All materials shall comply with the latest Japanese
Industrial Standards (JIS) or equivalent.
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All workmanship shall be of the highest class throughout to
ensure smooth and vibration free operation under all possible
operating conditions, and the design, dimensions and materials
of all parts shall be such that the stresses to which they may be
subjected shall not render them liable to distortion, undue wear,or damage under the most severe conditions encountered in
service.
All parts shall conform to the dimensions on and shall be built
in accordance with approved drawings. All joints, datum
surfaces, and mating components shall be machined and all
castings shall be spot faced for nuts. All machined finishes shall
be as shown on the Contractor's drawings.
In all mechanical parts, such as screws, bolts, studs, nuts and
threads for pipes etc., the unit of measurement should be in
Metric System.
Standard to be used
All materials to be furnished under the Contract shall conform
to the required standard for materials and test of Japan or
United States of America, or equivalent. The following
standards are referred to and abbreviations shown have beenused.
(a) Japanese Industrial Standard (JIS)
(b) American Society for Testing and Materials (ASTM)
Other International standards may be accepted, provided that
the requirement therein are, in opinion of the Engineer,
equivalent to the above standards. If the Contractor proposes
equivalent standard for such materials, the Contractor shall statethe exact nature of the changes, and shall submit complete
standard, and the information and data on the materials in
English language for the Engineer's approval.
If no standard is indicated, then the relevant Japanese Industrial
Standard, or American Society for Testing and Materials shall
apply.
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TECHNICAL SPECIFICATIONS
All electrical equipment and metal or electrical works shall
comply with the requirements and latest edition of the
following codes and standards, where applicable :
(a) Japanese Electro-Technical Committee's Standard (JEC)
(b) Japanese Technical Standard for Electrical Facilities
(c) Japanese Electric Machine Industry Association's Standard
(JEM)
(d)Japanese Cable-makers Association Standard (JCS)
(e) Local codes, other standard, instructed and/or approved
by the Engineer.
6.3.3 Piping Work
6.3.3.1 General
Steel pipe or PVC pipe shall be used for water lines. All
necessary studs, bolts, screws, nuts, washers, gaskets,
packing, supports, etc., required in connection with the
field assembly of the piping systems shall be supplied by
the Contractor. All gaskets and packing shall be of
approved material and of the type that has been proven
satisfactory for the service to which they will be subjected.
Where pipe is embedded in concrete, it shall be carefully
set to the required lines and grades, and securely braced
and held in place so that no movement shall occur during
concrete placement. Pipe supports to be embedded in
concrete shall be made of material which shall not
deteriorate, weaken or cause damage to the pipe. The
Contractor shall schedule and arrange his work of
installing pipes and pipe supports in coordination with the
Engineer.
The Contractor shall supply and install all pipe hangers,
brackets and supports required for the support of the
piping, including the drilling and caulking for the
expansion anchors and any work incidental to the setting
of such embedded anchors or inserts in concrete.
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Unless otherwise specified, pipe support shall be spaced at
7-feet (2.13 m) maximum. Vertical runs shall be supported
by means of pipe clamps or collars. Hangers and support
shall be painted.
6.3.3.2 Mortar Lined and Enamel Coated Steel Pipe
(a) General
Mortar lined and enamel coated steel pipe materials,
and method of manufacture of straight pipe and pipe
specials shall conform to AWWA-C200 Specifications
or equivalent, subject to the exceptions and
supplemental requirements contained herein. The
pipe, of the diameter and class as specified shall befurnished complete with rubber gaskets, if required,
and all specials and bends shall be provided as
shown.
(b) Cylinder Material
Cylinders shall be fabricated from hot-rolled carbon,
sheets or plates, conforming to ASTM A-570 Grades
C, D, and E, ASTM A-283 Grade D; steel pipeconforming with ASTM A-139, Grade B; or, if
approved by the Engineer, high strength low-alloy
steel conforming with ASTM A-572 Grade 42, or
equivalent JIS standards.
(c) Rubber Gasket
The rubber gasket furnished with the pipe shall be
continuous ring type, made of a special composition
rubber. The gasket shall be so formed and cured as tobe dense, homogenous, and have a smooth surface,
free of blisters, pits, and other imperfections. The
gasket shall be of sufficient volume to fill substantially
the recess provided, when the joint is assembled, and
shall be the sole element depended upon to make the
joint water-tight. The compound shall be of first
grade natural crude, synthetic rubber, or a suitable
combination thereto and shall conform with the
physical requirements listed below :
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Physical Requirements Value
Tensile Strength, min.
Natural RubberSynthetic and combination
Ultimate Elongation, % min.
Natural Rubber
Synthetic and combination
Shoredurometer, Type A
Compression set, percent of
original deflection, max.
Tensile strength after aging,
percent of original tensile
strength, min. (Oxygen
pressure test or air heat test)
160 kg per sq cm150 kg per sq cm
500%
425%
40-65
20%
80%
(d) Welded Joints
Where welded joints are provided, weld bell type
joints may be used, or the bell may be cut back or afiller rod added so as to permit a field weld between
the bell and spigot joint rings.
(e) Pipe Design
Design parameter shall be as follows :
For Cement-Lined Steel Pipes : (Class 150)
Nominal
Diameter (mm)
Steel Cylinders
Thickness (mm)
300 and under
350 - 500
600 - 700
750 - 900
1000 - 1200
4.70
6.00
7.90
9.50
11.10
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Outside diameters of cement-lined, coal-tar coated
and surface painted steel pipes
Nominal
Diameter (mm)
Outside
Diameter (mm)100
150
200
250
300
350
400
450
500600
700
750
800
900
1000
1100
1200
114.30
168.30
219.10
273.10
323.90
391.00
441.80
506.60
557.40661.60
763.20
817.80
868.60
970.20
1075.00
1176.60
1278.20
(f) Lining
The mortar for pipe lining shall consist of one (1) part
of cement to not more than three (3) parts of sand by
weight and shall develop a compressive strength of
not less than 175m kg per sq cm at 28 days. The
cement mortar lining shall be applied by the results.
The process used in the application of the lining shall
produce a smooth dense durable surface, free frompockets, voids, over-sanded areas, blisters, and
excessively cracked areas. Except where otherwise
specified or shown, lining thickness shall be as
follows, with a tolerance of plus or minus twenty-five
percent (25%).
Nominal
Diameter (mm)
Steel Cylinders
Thickness (mm)
under 300 mm300 - 400
6 mm13 mm
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over 400 mm 20 mm
(g) Hydrostatic Pressure Test
All steel cylinders shall be subjected to a hydrostatic
pressure test which stresses the steel to 1760 kg per sq
cm. While under pressure test, all welds shall be
thoroughly inspected, and all parts showing leakage
shall be marked. Cylinders which show any leakage
under test shall be rewelded at the point of leakage,
and subjected to another hydrostatic test.
(h) Specials
(1) Definition
Specials are defined as bends, reducers, wyes,
tees, crosses, outlets, and manifolds, wherever
located, and all piping above ground or in
structures.
(2) Design
Except as otherwise provided herein , materials,
fabrication and shop testing of straight pipe shallconform with the "AWWA Standard for Steel
Water Pipe, 6 Inches and Larger" (AWWA C-
200). Minimum plate thickness of specials shall
be computed using the following formula :
T =
where :
T = plate thickness in inches
D = outside diameter of steel cylinder
in inches
P = design pressure, psi
S = factor of safety 2.50
Y = specified yield point of steel in
psi
but in case shall the design stress (Y/S) exceed
930 kg per sq cm nor shall plate thickness be less
than the following :
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Nominal PipeDiameter (mm)
Pipe Manifolds
Piping Above
Ground Piping in
Structures Fittingsabove Ground (mm)
Fittings
UndergroundInstallation (mm)
300 and under
350 - 500
600 - 700
750 - 900
1000 - 1200
4.70 mm
6.00 mm
7.90 mm
9.50 mm
11.10 mm
4.70 mm
4.70 mm
6.00 mm
7.90 mm
9.50 mm
(3) Outlets, Tees, Wyes, and Crosses
Outlets shall be welded to the steel cylinder of
the pipe. Following this, all outlets larger than
50 mm in diameter shall be provided with steel
reinforcing saddles, wrapper plates, or crotch
plates, or they shall be fabricated in their
entirety of steel plates having a thickness equal
to the sum of the required thickness of the
saddle or wrapper plate, plus the cylinder to
which they are attached.
Such saddles or wrapper plates shall be of steel
plate, at least 1.25 times the thickness of the pipe
cylinder to which the outlet is attached. The
total cross-sectional area of the saddle or
wrapper plate shall be at least 1.25 times the
product of the cut-out length and the plate
thickness of the pipe, as determined in the
equation above. The overall width of the saddle
or wrapper plate shall not be more than 2 times,
and not less than 1.67 times, the maximum
dimensions of the cut-out. Outlets 300 mm and
smaller may be fabricated from schedule 30 or
heavier steel pipe in the standard outside
diameters, i.e., 324 mm, 273 mm, 219 mm, 169
mm, and 144 mm.
Where required, crotch plates shall be provided,
and designed according to the nomographmethod described in AWWA Manual M-11,
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Section 19.5, or AWWA Journal, Vol. 47, No. 6,
June 1955, pp. 617 to 623.
Tees, wyes, and crosses shall either be fabricated
of steel plate or provided with wrapper plates orwith crotch plates. The thickness of the plate or
plates, exclusive of crotch plates. The thickness
of the plate or plates, exclusive of crotch plates,
being such that when multiplied by the diameter
of the opening, shall not be less than 1.25 times
the cross-sectional area of the cutout. Where
tees, wyes and crosses are fabricated from steel
plate with out wrapper plates, the thickness of
the plate shall not be less than 2.5 times therequired plate thickness as shown in the
preceding table for such fittings.
(4) Dimensions
Unless otherwise shown, dimensions of specials
shall conform with "AWWA Standard for
Dimensions for Steel Water Pipe Fittings
(AWWA C-208) for Service in Transmission and
Distribution Systems."
(5) Steel Welding Fittings
Steel Welding fittings shall conform with ASTM
A234.
(6) Ends for Mechanical Type Couplings
Except as otherwise provided herein, where
mechanical-type couplings are indicated, theends of the pipe shall be banded with Type C
collared ends, using double fillet welds. Where
pipe 300 mm (12 in) and smaller is furnished in
standard schedule thickness equals or exceeds
the coupling manufacturer's minimum wall
thickness, the pipe ends may be grooved.
(7) Flanges
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Flanges shall have flat or raised faces. Flanges
shall be attached with bolt holes straddling the
vertical axis of the pipe.
(8) Shop Testing
Upon completion of welding, but before lining
and coating, each special shall be bulkheaded
and tested under a hydrostatic pressure of not
less than one and one-half (1-1/2) times the
pressure for which the pipe has been designed;
provided, however, that if straight pipe used in
fabricating the special has been previously tested
in accordance with sub-clause (h)(2) herein, the
circumferential welds may be tested by a dye
penetration process using Turco-Dy-Check or
approved equal with no further hydrostatic tests.
Any pinholes or porous welds, which may be
reveled by the test, shall be chipped out ad
rewelded, and the special retested.
(9) Lining
All requirements pertaining to thickness,application and curing of lining specified for
straight pipe shall apply to specials, with the
following provisions.. If the special cannot be
lined centrifugally, it shall be lined by hand. In
such case, the lining shall be reinforced with 50
mm x 100 mm No. 12 welded wire fabric
positioned approximately in the centers shall
extend circumferentially around the pipe with
the fabric securely fastened to the pipe. Splicesshall be lapped 100 mm, and the free ends tied
or looped to assure continuity.
(10)Coating
All requirements pertaining to coating specified
for straight pipe shall apply to specials. Unless
otherwise shown, the coating on the buried
portion of a pipe section passing through a
structure wall shall extend 50 mm inside the
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outer surface of the wall or to the wall flange, if
one is indicated. Pipe above ground or in
structure shall be field-painted, as specified in
Painting and Coatings.
(11)Marking
A mark indicating the true vertical axis of the
special shall be placed on the top and bottom of
the special.
(i) Internal Bracing
(1) General
Pipe sections 450 mm and larger shall be braced
internally as soon as practicable after the cement
mortar lining has been applied.
(2) 450 mm through 750 mm Diameter Pipe
Pipe sections shall be braced within 300 mm of
each end with two 2 x 4s wedged in the pipe at
right angles to each other.
(3) Larger than 750 mm through 1200 mm Diameter
Pipe
Pipe sections shall be braced within 300 mm of
each end, and at intervals not exceeding 3 m
along the pipe length, with two 2 x 4s wedged in
the pipe at right angles to each other.
(4) Larger than 1200 mm Diameter Pipe
Pipe sections shall be braced within 300 mm of
each and, and at intervals not exceeding 3 m
along the pipe length, with two 4 x 4s wedged in
the pipe at right angles.
(j) Cleanliness of Pipe
The interior of each pipe sections and special shall be
clean, and free of foreign materials when they aredelivered to the site of the work.
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(k) Transport and Handling
Coal tar enamel coated steel pipe shall be transported
and handled as specified herein. Any pipe section
that becomes damaged as a result of impropertransporting, handling or stockpiling shall be
repaired to the satisfaction of the Engineer. Where
damaged areas are extensive or where, in the
Engineer's opinion, field repairs are not practicable,
the Engineer may order the Contractor to remove the
damaged pipe section from the site of the work and
replace it with a new section.
Transporting and handling of enamel coated pipe
shall conform with the requirements of AWWA
Standard C-203. After enamel coated pipe has been
delivered to the trench site, any section of pipe which,
in the Engineer's opinion, indicates possible coating
damage, shall be spark tested by the Contractor, in the
presence of the Engineer, at the expense of the
Contractor. Any damaged areas in the enamel
coating shall be field-repaired using hot coal tar
enamel or the section of pipe replaced as specified
above.
(l) Installation of Piping
(1) General
Unless otherwise provided, the Contractor shall
furnish and install all pipes, specials, fittings,
closure pieces, valves, supports, bolts, nuts,
gaskets, jointing materials, and all otherappurtenances as shown and as required to
provide a complete and workable installation.
Where pipe support details are shown, supports
shall conform thereto, and shall be placed as
indicated; provided, that the support for all
exposed piping shall be complete and adequate,
regardless of whether or not supporting devices
are specifically shown. Concrete thrust blocks,
anchor blocks, or welded joints shall beprovided at all junctions, changes in direction
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exceeding 11-1/2 degrees or where otherwise
shown. At all times when the work of installing
pipe is not in progress, all openings into the pipe
and the ends of the pipe in trenches or structures
shall be kept tightly closed to prevent entrance ofanimals and foreign materials. The Contractor
shall take all necessary precautions to prevent
the pipe from floating due to water entering the
trench from any source, and shall assume full
responsibility for any damage due to this cause,
and shall, at his own expense, restore and
replace the pipe to its specified condition and
grade, if it is displaced due to floating. The
Contractor shall maintain the inside of the pipefree from foreign material, and in a clean and
sanitary condition until its acceptance by the
Engineer.
(2) Laying
Trenches shall be in a reasonably dry condition
when the pipe is laid. Necessary facilities,
including slings, shall be provided for lowering
and properly placing the pipe section in the
trench without damage. The pipe sections shall
be laid to the line and grade as shown, and they
shall be closely jointed to form a smooth flow
line. Immediately before placing each section of
pipe in final position for jointing, the bedding
for the pipe shall be checked for firmness and
uniformity of surface.
(3) Rubber and Gasket Joints
The rubber gasket joints shall be made by
properly lubricating the rubber gasket with a
suitable vegetable compound soap before it is
placed in the groove, with care taken to equalize
the stress in the gasket around the circumference
of the joint. The gasket shall not be twisted,
rolled, cut, crimped,, or otherwise injured or
forced out of position during the closure of thejoint. A "feeler" gage shall be used to check the
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position of the rubber gasket after the joint has
been telescoped.
(4) Field-Welded Joints
Field welding of pipe joints shall conform with
the requirements of the "AWWA Standards for
Field Welding of Steel Water Pipe Joints"
(AWWA C206). Prior to welding, the joint shall
be made up in accordance with Subsection (l)(3)
and(l)(5) herein. Such joints shall be inspected
and approved by the Engineer before any
protective coating is placed around the outside
of the joint.
(5) Protective Coatings
With pipe smaller than 450 mm in diameter,
before the spigot is inserted into the bell, the bell
shall be daubed with mortar containing one (1)
part of cement to three (3) parts of sand by
weight. The spigot end then shall be forced to
the bottom of the bell, and excess mortar on the
inside of joint hall be swabbed out. With pipe450 mm in diameter and larger, joints shall be
pointed on the inside with mortar, as specified
for field joints in AWWA Standard C205, after
the backfill has been placed. After coated pipe
section have been joined, the coating shall be
made continuous across the joints, forming a
coating equivalent to the factory-applied coating
of adjacent pipe sections. Coating and spark
testing of coal tar enamel field joints shall be asspecified in AWWA Standard C203, and shall be
performed at the expenses of the Contractor.
The use of coal tar tape to provide the required
protection shall not be permitted.
After the pipe sections on cement mortar coated
pipe have been joined, but before backfilling has
been completed, the outside annular space
between pipe sections shall be completely filledwith grout. The grout shall be poured in such a
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manner that all exposed portions of metal joints
shall be completely protected with cement
mortar. Grout shall consist of one (1) part of
cement to three (3) parts of sand, by weight, and
shall be sufficiently fluid to permit it to bepoured into the joint space. Exterior field joints
shall be coated with cement mortar, retained by
suitable forms so as to bridge the joint. The
mortar shall be compacted within the form to
produce dense coating without voids. The joint
coating shall be kept moist until the backfill is
placed.
(6) Butt-straps
Where a butt-strap is used, both the interior and
exterior surfaces of the but-strap shall be given a
coating equivalent to the factory-applied coating
of the adjoining pipe sections. Mortar coating
shall be reinforced with wire mesh. The mortar
lining shall be reinforced with wire mesh,
where the exposed length of the butt-strap, as
measured between the ends of the connected
pipe section, exceeds 100 mm. Butt-straps used
as closure pieces shall be provided with hand
holes for repair of the lining.
6.3.3.3 Small Steel Pipe
Unless otherwise shown, galvanized steel pipe, sizes less
than 100 mm in diameter and smaller, shall conform with
the requirements of the "Specifications for Black and Hot-
Dipped Zinc Coated (Galvanized) Welded and SeamlessSteel Pipe for Ordinary Uses" (ASTM A-120), and shall be
Schedule 40. Galvanized steel pipe shall not be cement
mortar-lined, unless otherwise specified. Fittings for
galvanized steel pipe shall be of galvanized malleable iron,
Galvanized and black steel pipe shall not be used for
buried service, except where shown on the Drawings.
Galvanized steel pipe for service connections shall be
allowed only as specifically shown on the Drawings. Thepipe shall be wrapped with a 500 micron thick PVC tape to
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a total thickness of 1000 microns, with half width
overlapping. PVC tape shall be applied in accordance with
the manufacturer 's recommendations.
6.3.3.4 PVC Pipes
Polyvinyl chloride pipes shall conform to JIS K6742 and/or
K6741, and be laid and jointed in accordance with the
manufacturer's instructions and to the Engineer's
satisfaction.
After the pipes have been laid, they shall be left exposed,
haunched or surrounded in concrete or covered with spoil
as required on the Drawings. Where covering with spoil is
done, care shall be taken to prevent damage due to largestone striking the pipe by removing large stones from the
layer of spoil immediately against the pipe or by other
means.
6.3.3.5 Pressure and Leakage Testing
(a) General
The Contractor shall furnish all equipment, labor and
material, including taps, valves, and bulkheads, as
required, exclusive of water and water meter testing.
The water and any water meter used for testing shall
be furnished by the Employer, but the Contractor
shall provide the facilities necessary to convey the
water from the designated source to the points of use.
All testing shall be done in the presence of the
Engineer.
(b) Pipeline Testing
All pipelines shall be thoroughly flushed out with
water prior to testing. The Contractor shall test the
pipeline in section prior to permanent resurfacing
after the trench is backfilled, but with joints exposed
for examination, except in heavily traveled roadways.
Maximum length of test sections shall be 500 metres
for distribution mains and 1, 000 metres for
transmission mains, unless otherwise approved by theEngineer. Where test sections are approved which
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exceed the above maximum lengths, the allowable
leakage for the lengths in excess of the maximum
allowable shall be reduced by fifty percent (50%).
The pipeline shall not be filled with water until the
following curing period have elapsed.
Description
Minimum
Allowable Time
1.
2.
3.
Cement Mortar Linings
Cement Mortar at Joints
Concrete Thrust Block
14 days
8 hours
a. Standard Cement
b. High Early Strength Cement
7 days
39 hours
The pipeline shall be prepared for testing by closing
valves, when available, or by placing temporary
bulkheads in the pipe and filling the line slowly with
water. During the filling of the pipe, and before the
application of the specified test pressure, all air shall
be expelled from the pipeline. To accomplish this,
taps shall be made, if necessary, at profits of highest
elevation, and after completion of the test; and taps
shall be tightly plugged, unless otherwise specified.After the line or section thereof has been completely
filled, it shall be allowed to stand under a slight
pressure for a minimum of forty-eight (48) hours, to
allow the escape of air from any air pockets, and to
allow the pipe or mortar to absorb as much water as
possible.
During this period, all exposed pipes, fittings, valves,
hydrants, joints, coupling shall be examined for leaks.if found to be cracked or defective, they shall be
removed and replaced by the Contractor with sound
material at his own expense. The pipeline shall then
be refilled, and all bulkheads, joints, and connections
shall be examined for leaks. If any are found, these
shall then be refilled, and all bulkheads, joints, and
connections shall be examined for leaks. If any are
found, these shall be stopped. The test shall consist of
holding the test pressure on each section of the linefor a period of two (2) hours. The test pressure at the
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lowest point shall be 690 KPa (100 psi) or 1.0 MPa (150
psi) according to the class of pipe installed, class 100
or class 150, and as approved by the Engineer.
Pressure gauges shall also be provided at all ends of
the section tested. The water necessary to maintainthe pressure shall be measured through a meter or by
other means satisfactory to the Engineer. The leakage
shall consider the amount of water entering the
pipeline during the two-hour test period. The
allowable leakage for asbestos cement pipe shall not
exceed the values listed in Table 1 of the "AWWA
Standard for Installation of Asbestos Cement Pipe"
(AWWA C-603), The allowable leakage for cast iron
pipe or ductile iron pipe shall not exceed the valueslisted in Table 3 of the AWWA Standard for
Installation of Cast Iron Water Main (AWWA C-600).
All other types of pipes shall have an allowable
leakage not exceeding 1.85 L/mm, (20 gal/in) of
diameter of pipe per kilometer per day. Should any
test of a section of pipeline disclose joint leakage
greater than that permitted, the Contractor shall, at
his own expense, locate and repair or replace the
defective pipe, fitting, joint coupling, or otherappurtenance. The test shall then be repeated until
the leakage is within the permitted allowance.
Closure pieces between newly installed and existing
mains shall be tested after the pipe has passed the
pressure and leakage test specified above. The test
shall include subjecting the joint to a pressure of 345
KPa (50 psi) for a period of five (5) minutes, and
visually checking for leakage. All visible leaks shallbe repaired by the Contractor at no expense to the
Employer.
6.3.4 Valves
6.3.4.1 General
The Contractor shall furnish and install all valves as
specified herein, and as shown on the Drawings. All
valves shall be new and of current manufacture.
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Flanged valves may be plain faced with serrated gasket
surface or raised. Flanges of valves for water working
pressure of 1.2 MPa (175 psi) or less shall be faced and
drilled of 125-lb American Standard dimensions; flanges of
valves for water working pressures greater than 1.2 MPa(175 psi) shall be faced and drilled to 250-lb American
Standard dimensions.
Each valve body shall be tested under a test pressure equal
to twice its design water working pressure.
All valves shall be provided with a exterior protective
coating in accordance with the pertinent provisions of the
Specifications.
When the operating nut of a buried valve is located more
than 1.5 metres below the ground surface, the Contractor
shall provide and install in the valve box a steam
extension. The bottom of the extension shall be securely
fastened to the operating nut of the valve, and the top of
the extension shall be centered in the valve box.
The Contractor shall furnish a minimum of six (6) tee-
handle valve keys of variable lengths, sufficient to permitoperation of all buried valves regardless of depth, by
operators of average height working in normal position.
Where the number of valves to be provided exceeds thirty
(30) units, the Contractor shall provide one (1) valve key
for every five (5) additional valves or a fraction thereof.
Operating nut shall turn counter-clockwise to open.
6.3.4.2 Gate Valves
(a) Valves
All valves shall conform with the "Standard Systems"
(AWWA C509). Gate Valves, where the pipeline
design pressure is 1.0 MPa (150 psi) or less, shall be
designed for a minimum water working pressure of
1.0 MPa (150 psi), and shall be cast iron bodied, with
resilient seats applied to the body and gate. Disksshall be cast iron with bronze disc rings, and the seat
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tested with twice the specified rated pressure
applied to one side of the gate and zero pressure
on the other side. The test shall be made in each
direct across the gate. Under this hydrostatic
test, the Contractor may make special provisionsto prevent leakage past the seats. No part of the
valve or gate shall be permanently deformed by
the test.
(5) Torque Test
A prototype of each size shall be overtorqued in
the closed and open positions, to demonstrate no
direction of the valve stem or damage to the
resilient seat as evidenced by failure to seal at
rated pressure. The applied torque shall be 250
ft-lb for 3 and 4 NRS valves, and 350 ft-lb for 6,
8, 10, and 12 NRS valves (1.0 ft-lb = 0.736
Newton-meter = 0.66 kg-m).
(6) Leakage Test
Two prototype valves of each size chosen by the
Engineer to represent the extremes of seatcompression shall be fully opened and closed to
a seal for 500 complete cycles with sufficient flow
that the valve is at 200 psi pressure differential at
the point of opening and closing. The valves
shall be drop-tight under rated pressure
differential applied alternately to each side of the
gate after completion of the tests.
(7) Pressure Test
One prototype of each valve size shall be tested
to 500 psi with the closure member in the open
position. There shall be no rupture or cracking
of the valve body, valve bonnet, or seal plate.
Leakage at pressure-containing joints shall not
be cause for failure of the test.
6.3.4.3 Butterfly Valves
(a) Valves
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Butterfly valves shall conform with the "AWWA
Standard for Rubber -Seated Butterfly Valves"
(AWWA C504) subject to the following requirements.
Valves shall be of Class 150B and, unless otherwise
specified, may either be short-bodied to long-bodied.Shaft seals shall be designed for use with standard
split V-type packing or "O" ring seals. The valve ends
shall be either flanged or of the wafer type, except
where otherwise shown on the Drawings.
(b) Operators
Operators shall conform with the above-referenced
AWWA Standard, subject to the following
requirements: Valves shall be equipped with 50 mm
square operating nuts or with handwheels 600 mm
maximum diameter, as specified, and shall be
provided with watertight gear housings.
The Contractor shall furnish a written certification
stating that the operator torque has been computed,
and the operators have been sized to meet the full
AWWA Class specified in Subsection (a) herein.
(c) Testing Requirements
(1) Performance Tests
Each valve that has the operator directly on the
valve shall be shop-operated three times from
the fully closed to the fully opened position, and
the reverse, under a no-flow condition, to
demonstrate that the complete assembly is
workable.
(2) Leakage Tests
Each valve shall be shop-tested for leaks in the
closed position. The test shall be conducted
with the body flanges in a horizontal plane.
With the disc in the closed position, air pressure
shall be supplied to the lower face of the disc for
the full test duration as follows :
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6.3.4.5 Air Vacuum and Air Release Valves
Air vacuum and air release valves shall have threaded
connections. The bodies shall be of high-strength cast iron,
and the float shall be of stainless steel. Float guidesbushings, lever pens and all other internal parts shall be
constructed of stainless steel or bronze. Seat washers and
gasket shall be of a material insuring water-tightness with
a minimum of maintenance. Valves shall be designed for a
water working pressure of not less than 1.0 MPa (150 psi).
All valves shall be designed to automatically operate so
that they will : (a) positively open under atmospheric
pressure (as water drains from the body of the valve, it will
allow air to flow into the pipe while it is being emptied);(b) positively close as water, under low head, fills the body
of the valve ; (c) not blow-shut under high velocity air
discharge; and (d) permit the escape of accumulated air
under pressure while the pipe is in operation. The valves
shall be either direct or lever operating.
6.3.4.6 Air Vacuum Valves
Air vacuum valves, of sizes up to and including 100 mm (4
in) in diameter, shall have threaded connections except
where otherwise shown on the Drawings. The bodies shall
be of high strength cast iron, and the float shall be of
stainless steel. All internal parts such as float guides,
bushings, and baffle retaining screws, etc., shall be either
stainless steel or bronze. Seat washers and gaskets shall be
of a material insuring water tightness with a minimum of
maintenance. Valves shall be designed for a water working
pressure of not less than 1.0 MPa (150 psi). All valves shall
be designed to automatically operate so that they will : (a)
positively open under atmospheric pressure (as water
drains from the body of the valve, it will allow air to flow
into the pipe while it is being emptied; and (b) positively
close as water, under low head, fills the body of the valve;
(c) not blow shut under high velocity discharge.
6.3.4.7 Air Release Valves
Air release valves, up to an including 100 mm (4 in.) indiameter, shall have threaded connections, except where
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otherwise shown on the Drawings, and shall be designed
for a water working pressure of 1.0 MPa (150 psi). The
body shall be of high strength cast iron, and the float shall
be of stainless steel. All internal parts, except the seat,
shall be of stainless steel or bronze. The seat shall be ofmaterial insuring water tightness with a minimum of
maintenance. The valves shall be designed to
automatically permit the escape of accumulated air under
pressure while the pipe is in operation. The valves shall be
either direct or lever operating.
6.3.4.8 Float Valves
Float valves shall be as shown on the Drawings.
6.3.4.9 Miscellaneous Small Valves
Valves 50 mm and smaller, unless otherwise specified shall
be all bronze or brass with threaded connections designed
for a water working pressure not less than 1.0 MPa (150
psi).
6.3.4.10 Plug Valves
Plug valves shall be lubricated 50 mm semi-steel
straightway valves with a working pressure of 175 lb. The
valves shall be wrench-operated, two-bolt cover type with
screwed ends. A complete locking device assembly shall
be provided for each valve, where indicated on the
Drawings.
6.3.4.11 Pressure Reducing Valves
The pressure reducing valve shall be of the diaphragmtype, equipped with a pilot spring to provide a range of
downstream pressure settings. the pressure reducing
valve shall be designed for a minimum water working
pressure of 1.0 MPa (150 psi), and shall be factory tested
under a hydrostatic pressure of at least 2.0 MPa (300 psi).
The valve body and cover shall be cast iron, meeting the
requirements of ASTM A48. The valve shall have flanged
ends, and the valve disc shall be non-metallic and
renewable. The main valve trim shall be of bronze, asspecified in ASTM Specification B62, and the valve seat
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shall be of brass, with type 18-8 stainless steel trim. The
diaphragm shall be of heavily reinforced synthetic rubber,
and shall be fully supported by the valve body. The valve
shall be coated in accordance with the pertinent provisions
of the Specifications.
6.3.4.12 Pressure Relief Valves
The pressure relief valve shall be of the diaphragm type.
The disc shall be non-metallic and renewable, and the
valve seat shall be replaceable. The main valve trim shall
be of bronze, conforming with ASTM Specification B62.
The pilot control shall be fully supported by the valve
body. The valve shall be coated in accordance with the
pertinent provisions of the Specifications.
6.3.4.13 Fire Protection System
(a) Fire Hydrant Heads
Fire hydrant heads shall be designed for a minimum
pressure of 1.0 MPa (150 psi) and have a 150 mm (6
in) flanged inlet, a 100 mm (4 in) streamer hose
outlets shall have hose caps and chains. Fire hydrantheads shall have a heavy duty body of bronze
conforming with ASTM Specification B-62 and shall
be cast-iron body in accordance with AWWA
Standard for Wet-Barrel Fire Hydrants (AWWA C503)
with bronze working parts. The stem shall be
provided with at least two (2) O-rings. Hydrant
valves shall open counter-clockwise. Burys for the
hydrants may be a commercial product or locally
fabricated.
(b) Wrenches
The Contractor shall provide three (3) sets of
pentagon spanner wrenches that will operate all
valves specified.
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6.3.5 Welding
All welding shall be done either manually by the shielded
metallic arc process or automatically by the shielded arc or
submerged arc method.
The Contractor shall submit a welding procedure for the
approval of the Engineer in the same manner as the drawings.
After the welding procedure has been approved, the Contractor
shall record it on a special drawing, which shall thereupon
become one of the drawings of the Contract. Weld sizes and
types shall be shown on all Contractor's drawings where
welding is required.
Plates to be joined be welding shall be accurately cut to size androlled by pressure to the proper curvature, which shall be
continuous from the edge. Flattening the curvature along the
edges with correction by blows shall not be allowed. The
dimensions and shape of the edges to be joined shall be such as
to allow thorough fusion and complete penetration, as
necessary, and the edges of plates shall be properly formed to
accommodate the various welding conditions. The surfaces of
the plates for a distance of 25 mm from the edge to be welded
shall be thoroughly cleaned of all rust, grease and scale, tobright metal.
Qualification of Welding Procedure
The technique of welding employed, the appearance and
quality of the welds made, and the methods used in correcting
defective work, shall conform to the American Welding Society
(AWS) Standard D.I.I., or other approved equivalent standard.
Qualification of Welders and Welding Operators
All welders and welding operators to be assigned to the works
shall have passed a qualification test, within the preceding six
months, for Welders and Welding Operators, in accordance
with JIS Z 3801 or equivalent. The Contractor shall furnish the
Engineer with three (3) certified copies of report of the results of
physical test of specimens welded in the qualification tests. If,
in the opinion of the Engineer, the work of any welder at any
time appears questionable he shall be required to pass the
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appropriate re-qualification test. All costs of qualification tests
shall be borne by the Contractor.
Welding Electrodes
The welding electrodes shall conform to JIS Z 3211 or 3212, low
hydrogen type covering or equivalent.
Stainless type weld metal, where used in the water passages for
protection against pitting, shall be of chromium nickel steel.
The type, chemical composition for this purpose shall be
subject to approval of the Engineer.
6.3.6 Protection, Cleaning and Painting
The following surfaces shall not be painted ;
(a) Surface which will be buried in concrete.
(b) Parts made of stainless steel, bronze or brass.
(c) Surfaces in rolling or sliding contact.
(d)Surfaces such as gear teeth.
(e) Wire ropes.
All machined parts of bearing surfaces shall be cleaned and
protected from corrosion before leaving the manufacturer's
shop, by the application of an approved rust preventive
compound or a peelable plastic film. Where the latter is
impracticable, such parts shall be heavily covered with high
melting point grease or other approved materials. Before
commencement of erection such parts shall be cleaned with
solvent and lapped or polished bright. The Contractor shall
supply the materials necessary for each cleaning.
All parts, other than machined parts, which shall be exposed
after erection shall be thoroughly cleaned and given at least
three (3) coats of best quality approved primer and at least two
(2) coats of best quality approved finish paint before leaving the
manufacturer's shop. The Contractor shall perform to the
equipment touch-up painting at the site after erection, except
such apparatus as panels and instruments, which shall be finish
painted under approved procedures before shipment. The
Contractor shall supply paint materials and necessary tools,
which are used at the Site, for the Plant.
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Primer shall be applied to surfaces in accordance with the paint
manufacturer's instructions. The surfaces shall be wiped clean
immediately prior to applying the paint. The primer and finish
coats of paint shall be applied using the methods and
equipment recommended by the manufacturer. The paintsystem selected shall have a proven life expectancy of not less
than five (5) years in the atmosphere prevailing at the Site.
The internal surface of all pipes shall be cleaned out by
approved methods before installation and again prior to
commissioning, to ensure freedom from dirt, rust, scale,
welding slag, etc. All exposed pipes shall be colour coded for
identification after erection is completed. The code system
shall be approved by the Engineer.
The final colour of all equipment shall be approved by the
Engineer but the Contractor shall propose a colour scheme for
the equipment and shall submit colour chips or paint samples.
A colour chip shall be included with the approved colour
schedule, for each type of finish to be applied at the Site.
Recommended