Cawangan Kejuruteraan Mekanikal – Edition 1

SECTION 3.3 TECHNICAL SPECIFICATIONS FOR WET RISER SYSTEM

1 GENERAL

The wet riser system includes but not limited to the following:

(1) Water storage tank

(2) Wet riser pump sets and jockey pump as detailed further in this specification

(3) 150mm diameter wet riser/s supply water pipe;

(4) 65mm diameter landing valves of pressure reducing hydrant type with
instantaneous female coupling and hand-wheel operated screwed down valve;

(5) Canvas hose, hose cradle, instantaneous male coupling and nozzle;

(6) 4-way breeching inlet complete with box;

(7) Automatic air release valve;

(8) Control panel.

2 BREECHING INLET

The breeching inlet shall be 150mm diameter 4-way type complying to MS 1210 : Part 3
complete with enclosure complying to MS 1210 : Part 5 and labelled “WET RISER
INLET” to enable the Jabatan Bomba Dan Penyelamat to pump water into the
installation by the use of their own equipment.

Breeching inlets shall be provided so that the firemen can pump into the wet riser tank to
make up for water used.

3 WATER STORAGE TANK

3.1 Hot Dipped Galvanised Pressed Steel

The storage tank shall be 5 mm thick hot dipped galvanised pressed steel sectional
water tank with hydraulically pressed flanges comply to BS 1564 : 1975 and treated with
two protective coats of paint, including bolting sections together, jointing with approved
plates and stiffeners, 5 mm chamfered pressed steel covers and mosquito-proof framed
access door.

3.2 Tank Accessories

The tank shall be supplied complete with :

(1) Level indicator of the float type;

(2) External and internal access ladders shall be of stainless steel;

(3) Overflow pipe (one size larger than the inlet pipe);

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(4) Scour pipe complete with drain valve and drain pipe;

(5) Inlet pipe c/w float ball (brass) valve (BS 1968 : 1953) and gate valve

(6) Outlet pipe connections to pumps and sized according to the drawings;

(7) Galvanised vent pipe of 75 mm diameter in the form of swan neck and covered
with stainless steel insect screen;

(8) One number of 600 mm diameter manholes with hinged cover situated near the
water inlet pipes.

(9) Warning pipe

(10) Stainless steel electrodes shall be provided in the storage water tank for sensing
low level condition and shall stop the pumps when the storage tank at low level.

The storage tank shall be installed on concrete plinths. The capacity and location of the
storage tank shall be as indicated in the Tender Drawings.

All offers of storage tank shall be supported by copies of the most current test
certificates from SIRIM, or other authorities having jurisdiction.

4 PUMPSET

The total number and the duty of each Wet Riser Pump to be provided are as indicated
in the Schedule of Design Requirements and/or Tender Drawings. The Wet Riser Pump
System comprises duty, standby and jockey pumps. The 'Duty Pump and the Jockey
Pump' to operate on normal electric power supply and the other a 'Standby Pump'
arranged to operate either on emergency power supply or by a diesel engine, in case of
mains failure, as indicated in the Schedule of Design Requirements and/or Tender
Drawings.

All pumps shall comprise of standard heavy duty end suction pump, and shall have a
smoothly cast volute, machined and balanced impeller fitted to stainless steel shaft and
sleeves, turning in heavy duty ball thrust and roller bearings, with leak proof mechanical
seals. The material of the impeller shall be high grade bronze/stainless steel as
indicated in Schedule of Design Requirements. All electric driven pumps shall be direct-
coupled to its driving motor by flexible type steel couplings and the whole unit shall be
mounted on a common rugged steel baseplate.

All pump units shall be mounted on raised concrete plinth and the overall height of the
plinth shall be as indicated in Schedule of Design Requirements and/or Tender
Drawings. The Contractor shall supply and install the concrete plinth and shall be
responsible to ensure smooth running, quiet operation with noise effectively reduced.

Each pump shall be fitted with suction strainer, suction valve, anti-vibration flexible
coupling, discharge 'non-slam' check valve, discharge valve, pressure gauges,
renewable casing wearing rings, renewable bronze shaft sleeves at the mechanical seal
and a priming cock as indicated in the drawings.

All pumps shall be specifically chosen for their particular operation as regards water
quantity, operating speed and working head.

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All pumps shall be carefully selected and operate on a suitable flow characteristic curve
as denoted by the pump characteristics i.e., at operating condition for a given flow rate
and head as indicated in Schedule of Design Requirements.

All pumps and motors shall have full load speed not exceeding 2900 rpm.

4.1 Pump Controls

The Wet Riser pumps shall be energised automatically by pressure switches. Where
the fire fighting system requires jockey pump, it shall be arranged such that the jockey
pump starts automatically when a fall in pressure occurs in the rising or distribution
mains exceeding 10% of the normal static pressure. When the normal static pressure in
the riser on distribution mains has been reestablished, the jockey pump will
automatically stop. In the case where the jockey pump has automatically started and the
pressure falls by 20% of the normal static pressure, it shall be arranged such that the
duty pump will automatically start.

The standby pump shall automatically take over in the event of the failure of the duty
pump. The jockey pump will automatically stop when the normal static pressure in the
riser or the distribution mains has been re-established. The duty and standby pumps can
only be stopped manually and they shall return automatically to the starting position after
the operation.

Provision for manual operation of the pumps shall also be provided.

4.2 Diesel Engine

The diesel engine shall be for driving the standby Wet Riser Pump and shall be of cold
starting, direct injection type, naturally aspirated single cylinder, air-cooled with variable
speed governor, fuel and lubricating oil filters and exhaust silencer. The engine shall be
of the industrial type suited for continuous heavy duty performance and shall be rated at
not more than 2900 rpm under standard atmospheric conditions. The power output shall
be as specified in the Schedule of Design Requirements, with all engine accessories
driven, or not less than 120 % of power required to drive the pump at design condition.

The engine is to be started directly by an extra heavy duty 12 Volts or 24 Volts electric
starter motor, from a bank of batteries. Automatic and manual starting and stopping shall
be provided. Manual starting switch shall be placed on the engine instrument panel.

The battery shall be extra heavy duty maintenance free lead acid rechargeable type of
sufficient capacity a minimum of not less than as indicated in Schedule of Design
Requirements for Wet Riser System in 5 hour rate of discharge, to provide six (6)
successive abortive starts of the engine without recharging, and housed in metal box
located beside the engine set. The box shall be lockable c/w lock set and have louvers
for sufficient ventilation.

The engine and pump set shall be mounted on raised concrete plinth. The overall height
of the plinth shall be as indicated in Schedule of Design Requirements and/or Tender
Drawings.

4.3 Fuel Tank

The fuel tank must be of welded steel conforming to BS EN 210:2000 for mild steel

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drums. The tank must be mounted above the inlet to the Engine Fuel Pump to provide a
gravity feed. The tank must be fitted with an indicator showing the level of the fuel in the
tank. The tank capacity is indicated in Schedule of Design Requirements.

Any valve in the fuel feed pipe between the fuel tank and the engine, must be placed
adjacent to the tank and it shall be locked in the open position. Pipe joints must be
soldered and the plastic tubing must not be used.

The following auxiliary equipment must be provided :

(1) A sludge and a sediment trap;

(2) An inspection and a cleaning hole;
(3) A filter between the fuel tank and fuel pump mounted in an accessible position
for cleaning;
(4) Means to enable the entire fuel system to be bled of air;
(5) Screwed plugs for air relief.

5 PIPEWORKS AND FITTINGS

5.1 Material

All piping shall be galvanized iron to BS EN 10255:2004 Class 'C'.

Square tees and elbows shall not be used. All changes of direction of the pipe run shall
be made with standard bends or long turn fittings.

All piping shall be cut with pipe cutters, accurately to dimensions determined on site and
worked into position without springing or forcing. Pipe thread shall be cut with threaded
dies and ends reamed before assembly. All screwed and socketed pipe joints shall be
made using Teflon. Any threaded tubing exposed after jointing shall be painted to
prevent corrosion.

A suitable automatic air release valve shall be fitted to each stack of risers or as
indicated in the Tender Drawings.

The Contractor shall ensure that all joints are tight and drip-proof. Pipe sleeves shall be
provided where pipes pierce through floors, ceilings or walls.

5.2 Underground Piping

All underground pipes shall be galvanised iron to BS EN 10255:2004 Class 'C',

preinsulated factory wrapped externally with bituminous comply to BS 534 : 1990 and
shall be complete with pipe marker at 20' interval.

Pipes run underground shall be laid at least 900 mm below the surface and adequate
provision for protection against vehicle movements and corrosion shall be taken. [The
insulated pipe shall be carefully laid on a sand bed completely free of stones, back-filled
with sand around and over the pipe to a minimum depth of 80 mm. The next layer of
backfill shall then be 300 mm deep of material free of stones; etc. The trench shall then
be filled with available material.]
* For road crossing, please refer to detail drawing.

All excavation, backfill of underground pipework shall be done by the Contractor. The

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work shall be supervised for alignment, levels and protection to the piping.

Piping shall be installed in accordance with good commercial practice. Care should
be taken to avoid possible restrictions due to foreign matter, faulty fabrication or
improper installation.

5.3 Joints

All pipes shall have screwed and socketed joints except for pipes of 100mm in diameter
and above which may be jointed by welded flange to BS 10 : 1962 or mechanical joint
or welded joint as shown in the drawings. All welding work shall be carried out by
certified welders.

Prior to commencement of welding work, contractor shall submit a copy of a competent

welder certificate for approval.

5.4 Pipe Supports

All vertical runs of pipe shall be adequately supported with suitable steel clamps at not
more than 1.8 metre centre. All horizontal runs of pipe shall be hung from ceiling slab or
walls with suitable steel hangers at not more than 2.4 metre centre. At the lowest point
of a vertical riser pipe, proper additional support shall be used to support from the floor
level.

All pipes shall be adequately supported by approved type steel hangers. The spacing of
these supports shall be as follows:-

SCHEDULE 1: Pipe Spacing

Nominal pipe diameter Maximum spacing
Horizontal spacing Vertical spacing
Up to and including 50 mm 3m 3.5 m
(2" diameter) bore
65 mm (2½") bore up to and 4m 4m
including 150 mm (6") bore

SCHEDULE 2: Anchoring
Pipe sizes Anchor & Hole Anchor Hole
(Diameter) Rod Size Diameter Length depth
25 mm – 50 mm 6 mm 8 mm 25 mm 25 mm
35 mm – 150 mm 9 mm 12 mm 40 mm 40 mm

5.5 PipeWork Accessories and Fittings

(1) Flexible Couplings shall be of wire and fibre moulded high-pressure rubber type.
The flange shall be integral with the fittings and shall be clamped in place using
split steel flanges for sizes 50 mm diameter and above. For sizes below 50 mm
diameter, a similar hose shall be used except that hose clips sealed with mastic
shall be used for connection.

(2) Strainers shall be installed upstream of all pumps. For 50 mm diameter and
below, the strainers shall be bronze body type. All strainers shall be fitted with
permanent magnets and removable bronze screens.

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(3) All valves supplied and installed shall conform to relevant standards:

Gate valves up to 50 mm (2") BS 1010-2:1973

Gate valves above 50 mm (2") BS 5163-1:2004
Check valves up to 50 mm (2") BS EN 13709:2002
Check valves above 50 mm (2") BS EN 13709:2002
Ball valves BS 1212

(4) All pipe fittings shall be galvanised iron, long radius, and conform to the following
standards:

(1) BS 143 and 1256 : 2000, threaded pipe fittings in malleable cast iron and
cast copper alloy.

(2) BS EN 10241:2000 wrought pipe fittings iron and steel (screwed BSP
thread).

(5) All flange fittings shall be factory welded. All flange connections shall have their
mating faces machined to a true surface square with the centre line pipe axis ±
3° deflection from the cross-sectional axis of the pipe. Suitable gaskets shall be
provided for leak proof connections.

(6) On-site welding operations should be avoided as far as possible, but if

unavoidable they shall be carried out in accordance with BS 2640 and BS 2971
and should be carried out by qualified welders.

6 VALVES

6.1 Landing valves

Landing valve shall comply with MS 1210 : Part 1. The landing valves should be boxed
up complying to MS 1210 : Part 4.

The valve shall also be supplied with a 65mm (2½") bore renewable valve washer for
screw down and 22mm (7/8”) diameter spindle with a 165mm (6½") diameter
handwheel.

The valve should be marked with a manufacturer’s name and its maximum test pressure
of more than 14 bar.

The landing valve shall generally be installed at a height of not more than 0.75 metre
from the floor with ample clearance to facilitate the connection of canvas hose.

7 FIRE HOSE ASSEMBLY

The fire hose supplied shall be 65mm diameter and of a minimum length of 30 metre
complete with 65 mm diameter quick coupling jet and spray nozzle. It shall be able to
withstand a testing pressure of more than 14 bar.

Each fire hose shall also be neatly stacked on a swing-type hose cradle fixed adjacent to
the landing valve.

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8 ELECTRICAL

The Contractor shall supply, install and connect all motors, switchboards, switchgears
and all other necessary equipment and carry out all electrical work necessary for the
efficient, safe and satisfactory operation of the systems.

The following electrical equipment and services shall be provided by the Contractor:

(1) All electrical motors, starters, isolators, cable boxes and isolating switches for
the sprinkler system.

(2) Electrical switchboards, control panels and wiring complete with isolators, fuse
switches, remote push buttons and indicator lights.

(3) Conduits, cable trays, cabling and control wiring between the electrical
switchboard subsidiary control panels and various item of the sprinkler system
equipment.

(4) All control equipment, control wiring and associated works.

(5) Conduits and wiring, including control switches and fused spare outlets as
indicated in the accompanying specification drawings.

The Contractor shall be required on completion of the electrical installation to provide a

complete "as built" wiring diagram identifying all the control circuits and the various
colour coding.

8.1 Electric Motors & Starters

All electric motors shall be totally enclosed, fan cooled and fully tropicalised with Class
'F' insulation to BS EN 60085:2004 and and designed to operate on 50 Hz power supply.

All motors shall be furnished with isolator gears and starter gear to BS EN 60947-4-
1:2001 & BS EN 60470:2001, IEC 60470:2000. The motors shall also be provided with
thermal overload protection in all phases, over-current protection devices and under
voltage releases.

All motors from 1.5kW to 75kW shall have a power factor of at least 0.85 at full load.
Motors of above 75kW shall have a power factor of 0.90 at full load.

The recommended type of construction and methods of starting for various sizes of
motors are given below:

kW PHASE CONSTRUCTION STARTER

Below 0.75 1 - Capacitor start induction run

0.75 to 2.2 3 Squirrel Cage Direct on Line

3 to 7.5 3 Squirrel Cage Star Delta/Auto Transformer

Above 7.5 3 Wound Rotor Primary & Secondary

Resistance/Soft starter

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8.2 Switchboard

Each switchboard shall be of the self-contained cubicle type, wall or floor mounted,
metalclad, flush fronted suitable for front and rear access housing air circuit breakers,
fuseswitches, switchfuses, isolators, contactors busbars, kWh meter, ammeter,
voltmeter, protective relays, selector switches, indicating lamps, current transformers,
cable terminating boxes, and anti-condensation heaters.

The Contractor shall submit the design of the control panel for the approval of S.O.

The metal cubicle switchboards shall be fabricated from steel sheets of not less than
2.0mm and epoxy coated with zinc for anti rust protection. It shall be of rigid construction
to withstand sag deformation or warping at any loads likely to be experienced during
normal operating, maintenance at maximum fault conditions. The front, top and back of
all cubicles shall be finished semi-gloss grey whilst the interior finished matt white.

Each compartment of the cubicle shall be fitted with a hinged door, concealed hinges,
turned edges and shall be fitted with a neoprene dust seal or felt rubber gaskets.

Switch operating handles shall be interlocked with the compartment door so that the
door may not be opened until the switch is off.

8.3 Fuseswitches and Switchfuses

All T.P. & N fuseswitches and switchfuses shall be of 500V rating and steel plate casing.
They shall have a parallel motion quick make and slow break mechanism.

Positive interlock shall be incorporated on the operating handle to ensure that the cover
can only be opened when the switch is in the "OFF" position and the fuse links are
isolated. The switch cannot be "ON" with the cover open. The switches shall be
complete with H.R.C. cartridge fuses and bolted type neutral link.

8.4 Earthing

All motors and equipment shall be earthed with a minimum wire size of 2.5mm tinned
copper and shall be sized in accordance with the IEE regulations. These earth wires
shall be neatly run back to connect up to the copper earth busbar provided in the main
switchboard.

8.5 Wiring and Cables

Unless otherwise stated all wiring to the equipment and controls shall be carried out in
conduit with PVC insulated 250V/600V grade cables and conforming with the relevant
current BS specifications.

All cables shall be of size capable of carrying the maximum current without exceeding 1
volt plus 2% of nominal voltage drop from consumer's terminals to any point in the
installation under normal conditions of service in accordance with the latest edition of the
IEE Regulations for the Electrical Equipment of Buildings. Cables smaller than 2.5mm²
shall not be permitted in any power circuits.

All conduits for electrical wiring shall be painted orange for identification from other
services.

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Where runs extend to equipment subject to vibration such as at motors, the final
connection shall be made with flexible galvanised conduit, unless otherwise called for.
The brass adaptors shall be brazed to the flexible conduit. A separate earth wire shall be
provided in the flexible conduit.

8.6 Cable Conduits, Trays & Trunking

For surface or concealed wiring, PVC insulated cables in GI conduits shall be employed.
Underground conduit wiring shall be carried out in PVC insulated and sheathed cables.

Capacities of conduits shall be in accordance with Table B5 of the latest edition of IEE
Regulations for the Electrical Equipment of Building. In general, conduits for PVC
insulated cables shall not be less than 18mm diameter.

In the main plant room, wiring to the various motors and equipment may be run on cable
trays. Such cable trays employed shall be constructed from perforated hot dipped
galvanised mild steel. Trays shall be of adequate width with upturned flange on both
sides 18mm deep and shall be completed with all necessary long radius bends, tees and
fixing brackets fabricated from galvanised mild steel flats.

Cable trunking may be employed in lieu of conduit where multiple runs would otherwise
occur. Trunking shall be manufactured from good quality hot dipped galvanised mild
steel of not less than 1.20mm for sizes up to 100mm and not less than 1.60mm for sizes
up to 152mm x 152mm and not less than 2.0mm for larger sizes.

8.7 PVC Cable

PVC cables for sub-mains shall comprise of high conductivity straided copper
conductors of the sizes shown on the drawings to BS 3360, PVC insulated to BS 2004
and 2746 as applicable. Cables drawn into non-metallic pipe conduits or fixed to cable
trays shall be PVC sheathed.

Insulant colours shall be in accordance with Table B4 of the latest edition of the IEE
Regulations for the Electrical Equipment of Buildings.

PVC insulated steel wire armoured PVC sheathed cable shall be manufactured and
tested to BS 3346.

8.8 Paper Insulated Cables

Paper insulated cables shall be manufactured and tested in accordance to BS 480 Part
1 and shall be of the mass impregnated non-draining paper insulated type. Cables for
415V (MV) service shall be insulated for 1100 volts when operating on a system with an
effectively earthed neutral.

8.9 MICC Cables

Where specified, installation work shall be carried out with MICC cables. The sizes of
the cables shall be suitable to ensure adequate current carrying capacity and that the
voltage drop at the apparatus is not excessive. All work and material must be in
accordance with the relevant British Standard Specification listed and the current rating
shall be as listed by the IEE. All joints and terminations of the conductors shall be
securely attached by fittings of an approved type which provide effective insulation and

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continuity of conductors and prevent the entry of moisture into the mineral insulation of
the cable.

The bending radius of MICC cables shall be not less than eight (8) times the overall
diameter. The termination of cables shall be at the provided earth bar inside the
switchboard and at a brass junction box near the motor or equipment terminal block. The
connection between the junction box and motor or equipment shall be made with PVC
cables heavy duty flexible conduit, fitted with approved brass screwed type flexible
conduit couplings. Cables from above 2.5mm² shall be terminated with a lug type or grip
cable sockets of approved manufacture.

The Contractor shall provide a steel sleeve where MICC cable passes through a
concrete floor. This sleeve shall extend at least 230mm above the floor to afford
mechanical protection to the cable. After inserting the cable, the sleeve shall be
effectively sealed with bitumen.

8.10 Reverse Cycle & Single Phasing Devices

Anti-reversal and anti-single phasing device of electronic type shall be installed for
EACH of the three phase motors installed in the system.

8.11 Rubber Mat

Approved type of rubber mat shall be provided infront of the switch board and any other
control board. The rubber mat shall extend to the full length of the switch board and shall
be of the thickness not less than 6 mm and width 1000 mm.

8.12 Lightning and Surge Protector

The Contractor shall provide lighting and surge protector for the control panel, fire alarm
panels, etc. to protect then from any transient voltage and lightning strike.

9 PAINTING

All items to be painted shall be first cleaned and prime coated. Over this the final colour
shall be applied in two coats. The paint shall be gloss-finish type.

The Schedule of Colours shall be as follows unless otherwise decided by the

Superintending Officer.

Water Tank Red

Pipes Red
Landing Valves Red
Inlet Connections Red
All Valves Red
Items exposed to weather Two coats of aluminium paint
Directional arrows White

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10 TESTING

After each section of the piping system has been installed it shall be blown clear by
suitable means, pressure tested to 14 bar and any leaks repaired.

After the complete piping system has been installed, the whole system shall be
subjected to a hydrostatic pressure test in the presence of the Superintending Officer or
his representative to withstand not less then 14 bar (200 psi) for 2 hours & 1 ½ times
working pressure for 24 hours.

The Contractor shall be responsible to arrange, set out and pay all fees in connection
these testing.

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