A Basic Design Guideline for Mechanical Engineering Systems Could Be Categorised Into Five (5)...

1. SANITARY AND SEWERAGE PIPE MANHOLE SERVICES

1.1.All design guideline for Sanitary and Sewerage Pipe Manhole Services are based on

Guide to Sewerage Systems - Malaysian Water Association (MWA)/(BS5572:1994)

1.2.Make sure all proposed design calculations and drawings documentation to be prepared

earlier and need to be endorsed & sign by the Clients before doing any final Building

Submissions to the authorities. (e.g. Majlis Perbandaran Selayang, Majlis Perbandaran

Kelang, Majlis Perbandaran Shah Alam, Dewan Bandaraya Kuala Lumpur and etc. Those

approval processes would take around three (3) to four (4) months from the date of

submission.

Adopted from http://leonim.blogspot.com/2011/02/basic-design-guideline-for-mechanical.html

http://leonim.blogspot.com/2011/02/basic-design-guideline-for-mechanical.html

2. HOT & COLD WATER PLUMBING SERVICES AND SUCTION &

ELEVATED ROOF WATER TANK & PUMPING SYSTEM

2.1. All proposed design guidelines are based on Guide to Water Supply System – JKR/MWA

2.2. Make sure all proposed design calculations and drawings for Hot & Water Plumbing

and Suction/Elevated Roof Water Tank and Pumping System need to be prepared for

Tender for Construction purposes and JBA/Syabas and District Council Authorities

submission and approval.

2.3. The Size of Elevated Storage/Domestic Water Tank is based on the number of

population per sq.ft. (100 sq.ft/ 1 person) or Specified Required Gallons of Water

Demand per sq.m(2.2 Ig/ 1 sq.m) – this case would be direct tapping from the Main

Bulk Water Meter to the Elevated Storage/Domestic Water Tank. Hence, under Penang

Water Authorities (PBA) the total Water Demand would be around 5.5 Igals/ 1 sq.m.

2.4. In any special case if there is a very low pressure from the Main Bulk Water Meter to

the Elevated Water Tank, it is required to have One Suction Tank that would be *1/3 of

Storage/day from the total water demand and balance 2/3 of Storage/day is for the

Elevated Roof/Storage Tank. It is noted that all final selection of Water Tank Size is

depends upon on the incoming size of the pipe from the Water Reticulation (e.g. Size

of Ductile Iron Pipe = 65 mm, need to consider the free board of 10” from the surface

of sitting ball valve to the inner surface of the tank height and the balance bottom

height of 3” where from the height of the water outlets to the inner surface of the

bottom water tank.

2.5. A Suction Pump (Booster – Multistage Vertical Type) need to be analysed and designed

for 6 to 8 hours Operation/day in a proper way by considering all water supply from

the Suction Tank to be controlled by On/Off Procedures (Pressure Regulating Control

Valves) where could be read off by the Motorised Valve at Roof Storage Tanks. The

effective capacity (KW) of the Suction Pump would be considered by the following

criteria’s:

2.6. Design flow rates (Q – Igpm) = Total Water Demand / 8 X 60 min.

Total Pump Head (ft.) = Highest Static Head + Pipe Friction Head Loss

2.7. (Pipe friction head loss = s.factor, 20% X Pipe friction factor [Equivalent Pipe Length +

Straight Pipe Length]

2.8. Min. Pump Cap. = 1.2 X Pump B.H.P X 0.746; i.e. Pump B.H.P = TPH X Q / 3300 X

Pump effieciency (60% to 65%)



2.9. The location of the Suction Tank would be at the Ground or Lower Ground Floor

depends upon S.O Architect’s requirements.

2.10. Material of Suction Tank shall be FRP – Fibre Reinforced Plastics or R.C –

Reinforced Concrete.

2.11. A Booster Pump for Roof Tanks calculations could be determined by considering

the number and type of fittings to be used and its individual loading unit’s factor. So,

by totaling up the number of loading unit’s factor then only the required Design Flow

Rates (Igmin. – Imperial Gallon/min.) could be determined by referring to CP310:1965

Graph – Fig.1 (Water Supply Rules – JKR)

2.12. Total Pump Head need to be considered by estimating the Total Pump Head

(TPH) would be considered same like determining the Suction Pump.

2.13. A Break Tank for Cold Water Plumbing Services only needed as per SYABAS

requirement if the High Rise Apartment/Condominium level height above 75 m.

2.14. Below table is a sample plant room & risers that for High Rise

Apartment/Condominium that need to be clarified with S.O’s Architects;



Sample Plant Room for Cold water:

Roof tank room 10m x 10m x 4.6m (H) Centre roof area

Roof pump room 4m x 2m x 3m (H) Shall be attached to roof tank

room

Suction tank room 10m x 5m x 3.5m (H) Within apartment footprint

Suction pump room 4m x 3m x 3.5m (H) Shall be attached to suction tank

room

Cold water riser 1.2m x 0.75m Required near staircase 1, 2 & 3

Cold Water Break Tank (if Building height > 75m)

(TANK TYPE : FRP)

a) Tank Sizing 4m(W) x 4m(L) x 2m(H) For the building height above

75m. Within 1 no. of

apartment unit for Block A &

B. At Level 17th. Sharing

with the apartment unit of

Wet Riser break tank.

b) Tank & Pump Room 4m(W) x 7m(L) x 2m(H)

Swimming Pool Requirement

a) Swimming Pool

Balancing Tank

Room

6(W) x 5(L) x 5(H) Within apartment footprint

(TANK TYPE : RC)

Swimming Pool Balancing

Tank Pump Room

5(W) x 5(L) x 5(H) Shall be attached to swimming

pool balancing tank room



3. AIR – CONDITIONING & MECHANICAL VENTILATION SERVICES

3.1. All proposed design guidelines are based on HVAC and Air – Conditioning System –

ASHRAE/MASHRAE or SMACNA

3.2. Make sure all proposed design calculations and drawings for Air - Conditioning and

Mechanical Ventilation System need to be prepared for Tender for Construction

purposes.

3.3. The selection of Chiller Unit is firstly to Determine the tentative heat loads for Chiller

Condensing unit by doing the estimation on the Average between maximum and

minimum of Grand Total Cooling Load/effective area, Sq.Ft. as can be referred to Table

1 – Design and Cooling Load Checks

3.4. (e.g. GTC – Hospital = 80 Btuh/Sq.Ft. Factories = 80 Btuh/Sq.Ft., Offices = 75

Btuh/Sq.Ft., Shopping Complexes = 60 Btuh/Sq.Ft. Houses, Condominiums &

Apartments = 65 Btuh/Sq.ft. and etc.).

3.5. Then only the Chiller Cooling Load in ‘Btuh’ Unit need to convert into Ton of

Refrigerant - T.R (1 T.R = 12,000 Btuh) and not to forget by adding up the Safety

factor of 10 to 15 percent.

3.6. Smoke Control System for the Air Handling Unit for all types of buildings should

consider the Suction Air and Return Air. A basic rule of thumbs as referred from below

formula;

CFM (Suction Air) = RSH (Room Sensible Heat)/1.08 X 15 and

CFM (Return Air) = 0.8 GTC

3.7. Cooling Tower Unit need to be determined by adding up 25% (i.e. multiply by factor of

1.25) from the total Chiller Cooling Unit. (T.R unit)

3.8. The Size of Make Up Water Tank need to be determined by considering below formula;

Total Size of Cooling Tower (CT-T.R) X 3.0 U.S Gallons X 8 hours of pump

operations.

(convert to Ig – Imperial Gallons, multiply by factor of 0.833)

3.9. Sub total capacity of Chilled Water Flow Rates - for individual AHU Units (m³/h) = (GTC,

KW)/1.16 X (7ºC - different of temp. on the refrigerating effects)

3.10. Total Capacity of Chilled Water Flow Rates (m³/h) = 7% of Sub – total capacity of

Chilled Water Flow Rates



3.11. Total Condenser Water Flow Rates (m³/h), as at 30ºC-32ºC = 25% of Total Chilled

Water Flow Rates(m³/h), as at 24ºC-26ºC

3.12. Chilled/Condensing Water Pump Capacity = Total Flow Rates,igpm

(Condenser/Chiller) X total pump head (ft)/3300 X Pump effieciency; considering 1 unit

each on standby and 2 units each on duty (total overall = 6 units of Condenser/Chilled

Water Pumps)

3.13. Chilled/Condenser Water Pipes could be determined same like the Cold Water

Pipe Calculations but the only difference is to take care any heat/cold losses from

those piping works by considering the fire rated pipe insulations.

3.14. Condenser Water flow rates for Water Cool Package Unit (l/min) = (GTC + Input)

KW / (7ºC - different of temp. on the refrigerating effects) X 0.07

3.15. Fan Coil Unit Power Consumption; for Air Cooled Package = 1.5KW/ton and Water

Cooled Package = 0.9KW/ton

3.16. Exhaust/Fresh Air Fan for Gen-set and Electrical Switch room; the Air – Change/hr

(ACH) = 15, Toilet = 10, Kitchen= 20, Basement = 6, Restaurant = 15 to 20 (depends

on the heat loads of the restaurant), Car-park = 12, Lift Motor Room = 12, Auditorium

= 0.14 cmm/seat, Canteen = 0.28 cmm/seat and the Air Flow Rates can be calculated,

CFM = Room Volume (m³) X ACH / 60

3.17. Total Pressure Losses for AHU Ducting Lines; Pressure Duct Losses = ( ? ft. X

0.1”wg/100ft) + fan losses = 0.2”wg + Grille Losses = 0.1” wg

3.18. AHU Fan Power Rated; Air Flow Rates (m³/s) X Total Pressure Losses (mm

wg)/102 X motor efficiency (65%)

3.19. The Air – Cooled Supply Velocity from the AHU – Air Handling Unit could be

determined by using the Ductulator (e.g. TRANE, YORK DUNHAM BUSH)

3.20. Air Fan Capacity for Kitchen Area (m³/hr) = Kitchen Room Size (m³) X 25 ACH / 1

hr.

3.21. Kitchen Hood Size = W (m) X L (m) X 1.02 (h)

3.22. Suction Air Fan at the Kitchen Hood (CFM) = (1.4 X 0.4m/s X 2(W+L) X 1.02, by

converting to CFM) X Grille losses, 0.5”wg



4. FIRE PROTECTION SERVICES & FIRE ALARM SYSTEM

All proposed design calculations and drawings for Fire Protection Services & Fire Alarm

System need to follow a design guidelines that based on the book title; Guide To Fire

Protection in Malaysia – 2nd.edition, March 2006 (Active Submission, by refer to Chapter

5 to 13 – Portable Fire Extinguisher, External Fire Hydrant System, Hose Reel System,

Dry Riser System, Wet Riser System, Downcomer System, Automatic Sprinkler System,

Automatic CO2 Extinguishing System, and Automatic Fire Detection & alarm System)

Pressurisation System in Building, Smoke Control System Using Natural Displacement

or Powered Extracted Ventilation, Fire Lift, and Emergency Power System would be put

under separate submission due to the building requirements (by refer to Chapter 14 to

17)

All Passive Submission and Performance Base would be under Architectural and C&S

Scope of Works Only. (Chapter 4 and 18 only)

Make sure all proposed design calculations and drawings for Active Fire Protection

Services need to be prepared for Tender for Construction purposes and BOMBA

submission and approval.



4.1. Portable Fire Extinguisher –

It could be categorised into different types of Media and Application/Classes by following its

Colour Coding;

Water – Suit for *Class A fires (in red colour code)

Foam – Suit for Class A & B fires (in cream colour code)

Dry Chemical Powder – Suit for Class A, B, C and E fires (in blue colour code)

Carbon Dioxide – Suit for Class B & E fires (in black colour code)

Halon – Suit for Military, Aviation or Special Application (in golden yellow colour

code)

Wet Chemical System – new requirement by BOMBA that need to be installed at all

Kitchen Areas. – suit under Class F

Selection of the P.F.E – Potable Fire Extinguisher; e.g., at the floor area of 1600m²:

0.065 X 1600 = 104A

104A = 13A X 8 Units of PFE Cylinders X 4 Kg; or

108A = 27A X 4 Units of PFE Cylinders X 6 Kg



4.2. External Fire Hydrant System –

4.2.1. Design Standard

– MS1489 Part 1 (Hydrant System, Hose Reels and Foam Inlets)

– MS1395 Part 1 (Pillar Hydrant)

4.2.2. Design Method of Fire Hydrant System:

4.2.2.1. Design Method could be categorized into two types of external fire

hydrant systems;

– Direct from main intake to all the pillars

– Pressurized by Fire Pumps

4.2.2.2. Pillar Hydrant Location is < 30m from the breeching inlet at the

building

4.2.2.3. Hydrant Pillar System location ≥ 6m from the building if it is

a High Rise Building.

4.2.2.4. Hydrant Pillar Spacing ≤ 90m in between and each location has a

min. 6m (width) that could withstand 26 tons.

4.2.2.5. Each Hydrant Pillar should be provided with 30m of 65mm dia.

Canvas Hose, Coupling and Nozzles that to be placed in the special

cabinets nearby.

4.2.2.6. In any special case for Pressurized Installation (used Pumps) each

Hydrant Pillars (twin outlets) need to have a Water Supply at the

minimum flow rates of 1000 lit./min (1m³/h) and at Working Pressure

of 4 Bar (58 Psi/9m head/30ft. head).

4.2.2.7. Each outlets from the Hydrant Pillars – 500 lit/min (0.5 m³/h) and at

min. Working Pressure of 2 Bar (29 Psi/4.5m head/15ft. head)

4.2.2.8. Pressure Regulating type of outlet valve need to be introduced if

ever the outlet pressure from the fire mains boost to 7 Bar (101.5

Psi/16m head/53ft. head)



4.2.2.9. Pipe Material of the Hydrant Systems could be categorized into two

(2) types that approved by BOMBA;

– Cement Lined Steel Pipe

– ABS (anti-corrosion pipe)

4.2.2.10.Hydrant Pump Specifications;

– One (1) Unit Standby – 3 m³/min (3000 lit./min) – Electrical/Diesel

Engine driven,

– One (1) Unit On Duty - 3 m³/min (3000 lit./min) – Electrical driven

and

– One (1) unit of Jockey Pump – To maintain system pressure and

as a Start–Up for On Duty/Standby Pumps and usually an

electrical motor driven with a capacity of around 120 lit./min

(0.12 m³/min)

4.2.2.11.The Flow rates for both Standby/On Duty Hydrant Pumps could be

increased depends upon the number of Pillar Hydrants to be

installed

– because the limitation for the flow rates of 3000 lit/min each

pumps are only limited to 3 n.o.s of Pillars hydrant only; i.e. 1

n.o.s of Pillar Hydrant = 1000 lit. /min and as example if 6 n.o.s

of Pillars Hydrant = 6000 lit. /min and so forth.

4.2.2.12.The Hydrant Pump-Set should be protected from weather (i.e. effect

by flooding season)

4.2.2.13.The Fire Water Storage Tank should be sized for a minimum

effective capacity of 135, 000 lit. /min (Approximately: 35,000 to

36,000 Imp. Gallons) that would consider the Upper Level height

(free board) and bottom level height (600mm/0.6m)

4.2.2.14.Before doing any testing on the Hydrant Pumps all procedures below

need to be followed;

– Starting the duty pump-set at 80% of the system pressure;

– Starting the standby pump – set at 60% of the system pressure;

and



– Starting and Stopping the jockey pump – set at 90% and 110% of

the system pressure.



4.3. Hose Reel System –


– M.S.1489 Part 1: Hydrant System, Hose Reels and Foam Inlets;

– M.S.1447 - Hose Reels with semi – rigid hose;

– M.S.1488: Semi – rigid hoses for first aid fixed installations.

4.3.2. Design Method of Hose Reel System;

4.3.2.1. It should be complied with M.S.1447 and stated detailed under the

10th.Schedule (refer to UBBL)

4.3.2.2. The location for each hose reel are usually to be placed where could

cover 30 meters of hose coverage between the hose reels stack.

4.3.2.3. Each hose reel outlet to discharge a minimum of 30 lit/min (1.8

m³/min) of water within 6 meters of all parts of the space protected.

4.3.2.4. The rubber hoses should comply to M.S 1488 (min: 30 m in length)

4.3.2.5. Size of Hose Reel Pipe is 50mm (nom. dia.) and the material is

Galvanised Steel – Medium Grade Class B for above ground but for

Underground G.I Pipe -Heavy Grade Class C & to be feed to

individual hose pipe size ≥ 25mm dia.

4.3.2.6. The pipe shall be painted with primer and finished with red paint or

may be identified with red bands.

4.3.2.7. Hose Reel Pumps – 1 (One) unit on Duty and 1 (One) unit on Standby

4.3.2.8. Pump Flow Rates – 120 lit/min@ operating pressure at 2 to 3 bars (4

Hose Reels could be activated at one time)

4.3.2.9. The Standby Hose Reel Pump – Set should be supplied with power

from the emergency generator or diesel engine driven (fuel supply

should be adequate for min. 1 hour of operation)

4.3.2.10.Starting and Stopping the Duty pump-set need to be set at 80% and

100% of System pressure respectively;



4.3.2.11.Starting and Stopping the Standby pump – set need to be set at 60%

to 100% of system pressure respectively.

4.3.2.12.Diesel pump – set should be capable of automatic starting but

should only be stopped manually.

4.3.2.13.If the total hose reel < 4 Units than no need to use emergency

power; i.e Electrical Generator or Diesel Engine Driven.

4.3.2.14.All hose reels system shall not be tapped off from Automatic

Sprinkler System

4.3.2.15.Min. Floor Size Area of Hose Reel Stacks : 1200mm - Length X

800mm - Depth (mm²)

4.3.2.16.Minimum Effective Capacity of Fire Water Storage Tank should be

sized based 2275 litres (500 Ig) for the first hose reel and 1137.5

liters (250 Ig) for every additional hose reel. The maximum effective

capacity is approximately 9100 litres (2001 Ig).

4.3.2.17.The Material used for the Fire Tank is either made from Pressed

Steel (hot dipped galvanised and coated internally with Bituminous

paints for corrosion protection), FRP – Fiberglass Reinforced Plastics

or R.C Concrete.

4.3.2.18.This Hose Reel Tank need to be refilled with 50mm Supply pipe and

at the min. flow rates of 150lit/min (33 Igpm)

4.3.2.19.Pump Rooms would be located at the Ground Floor or Roof Floor

Level and the min. Fire Protection Plant Room Size as following

below table;

Plant Room for Hose Reel Tank

Hose Reel Tank

Room

(TANK TYPE : RC)

3(W) x 2(L) x 5(H) Within apartment footprint and could be

shared with Wet Riser Tank Room if

Required.

If the location of hose reel tank at roof

top than it is advisable to combine with

a Roof Storage Water Tank (i.e Shopping

Complexes like Carrefour, Tesco or

Giant)



Ventilation slots should be provided with

insect screen to prevent entry of vermin



4.4. Dry Riser System –



– M.S.1210 Part 2: Landing Valves for Dry Risers;

– M.S 1210 Part 3: Inlet Breeching Inlet for Risers Inlet

– M.S 1210 Part 4: Boxes for Landing Valves for Dry Risers

4.4.2. Design Method of Dry Riser System;

4.4.2.1. It should be complied with UBBL 1984, the by Laws 230 and 232

4.4.2.2. Dry Risers are a form of internal hydrant and are only required for

buildings where the topmost floor is higher than 18.3 meters and

less than 30.5 meters.

4.4.2.3. Dry Risers are basically dry and all depends upon the Fire Engine to

pump water into the system by considering the Breeching Inlet to be

located about 30 meters from the External Hydrant System.

4.4.2.4. Landing Valves are provided on each floor and should comply with

M.S 1210: Part 2.

4.4.2.5. Those Landing Valves would be located within the fire access

lobbies, protected staircases or other protected lobbies at not more

than 0.75 meters from the floor level.

4.4.2.6. To protect the landing valves, boxes may be provided and these

should comply with M.S.1210 Part 4.

4.4.2.7. Fire Hose Reel Pipings > 38mm dia., 30 meters in length, complete

with 65mm dia. Quick Coupling and nozzle should be provided at

each landing valve.

4.4.2.8. Breeching Inlet would be installed at the bottom of the riser and

should comply with M.S. 1210: Part 3. The breeching inlet is

enclosed within a box, the enclosure should comply with M.S.1210

Part 5 and labeled ‘Dry Riser Inlet’ and a typical drain should be

provided at the bottom of the riser to drain the system after used.



4.4.2.9. 2 – Way Breeching Inlet should be provided for a 100mm dia. Of dry

riser pipes but 4 – Way Breeching Inlets : 200mm dia. Of Dry Riser

Pipes and should be located 18 meters from the fire appliance

access road. (the distance of fire fighters truck to be placed)

4.4.2.10.The riser pipe diameter size – 150mm usually located within the fire

access lobby or staircase if the highest outlet is more than 22.875m

above the breeching inlet. Otherwise the riser pipe diameter size –

100mm.

4.4.2.11.The material of the Riser Pipe shall be Galvanised Iron to B.S. 1387

(heavy gauge) or Class C, tested to 21 Bars (305 Psi)

4.4.2.12.All feeding Pipe-works that runs horizontally need to be sloped to

enable proper draining after used and also an Air Release Valve

should be installed at the top of the riser to relief air trapped in the

system.

4.4.2.13.The riser pipe should be electrically earthed or connected to the

building earth to achieve equipotential.

4.4.2.14.The riser to be hydraulically tested to a pressure of 14 Bars for 2

hours that to be measured at the Breeching inlet and not forget to

check all leakage at the joints and landing valves connections.



4.5. Wet Riser System –






4.5.2. Design Method of Wet Riser System;

4.5.2.1. It should be complied with UBBL 1984, the by Laws 231, 232 and

248

4.5.2.2. Wet Risers are a form of internal hydrant and are always charged

with water. The topmost floor is higher than 30.5 meters and less

than 70.15 meters for each stage of Wet Risers. If > than 70.15

meters, so a Break Tank is required.

4.5.2.3. Wet Riser System comprises duty fire pump with standby pump

discharging into a 150mm diameter riser pipe with landing valves at

each floor and to which canvas hose with nozzles can be connected

to direct the water jet at the fire.

4.5.2.4. The function of a Jockey Pump is to maintain system pressure.

4.5.2.5. Landing valves that usually being installed at each floor should

comply with M.S. 1210: Part 1 and located within fire fighting access

lobbies, protected staircases or other protected lobbies.

4.5.2.6. The height of the landing valves should be < 0.75 m from the floor

level and for the safety purposes this landing can be protected by

providing boxes and need to comply with M.S 1210: Part 4

4.5.2.7. Recommended pressure for each landing valve should be in between

4 to 7 bars (58 to 102 Psi)

4.5.2.8. Landing Valve could be categorised into two types : -



– Pressure reducing type with relief outlet – require a wet riser

return pipe

– Pressure reducing type without relief outlet

4.5.2.9. Size of the Fire Hose Canvas type ≥ 38mm and the required length

is 30m. complete with 65mm dia. Of quick coupling and jet and

spray nozzle should be provided in a hose cradle beside each

landing valve.

4.5.2.10.Breeching Inlet for the Wet Riser System is normally same with the

Dry Riser System where the firemen could usually pump the water

from the water source (External Fire Hydrant Pillar – located < 30m

from the breeching inlet) into the Wet Riser Storage Tank to make –

up for water used.

4.5.2.11.These breeching inlets need to be located < 18m from the fire

appliance access road.

4.5.2.12.The Breeching inlet should be a 4 – Way type complying with M.S

1210: Part 3 and enclosed within a box that also complies with M.S

1210: Part 5. These box enclosures need to be labelled as ‘Wet Riser

Inlet’ and to provide a drain at the bottom of the riser to drain the

system after use.

4.5.2.13.Wet Riser Main Pipeline usually located within the Smoke Lobby or

protected areas and such that all spaces are to be within 45m

coverage from a Landing Valve and more than one riser is required

for each floor.

4.5.2.14.Distance between the risers should not exceed 60m and also where

between the lowest and topmost landing valve in any upper stage

risers.

4.5.2.15.The Size of the Pipe Riser should be 150mm dia. (Galvanised Iron to

B.S. 1387 – Heavy Gauge or Class C)

4.5.2.16.The Size of Relief Pipe shall be at min. of 100mm dia. (Galvanised

Iron to B.S. 1387 – Medium Gauge or Class B, where discharging

back to the Wet Riser Tank whenever possible and all air relief need

to be installed at the top of the riser to relief any air trapped in the

system).



4.5.2.17.The Wet Risers pipe should be coated with primer and finished with

red gloss paint or any special condition those wet riser pipes can be

colour coded with red bands of 100mm width but only at the elbows

& tees need to be fully painted in red.

4.5.2.18.All Wet Riser Pipe should be electrically earthed to achieve

equipotential with the building.

4.5.2.19.There two sets of Wet Riser Pumps – One (1) unit is on duty and One

(1) unit on standby and both pump capacity are usually sized to

deliver 1500 l/min at a running pressure in between 4 to 7 Bars that

would cater for three (3) landing valves at one time of operation

during building in fire.

4.5.2.20.All Standby Wet Riser Pump-set should be supplied with power from

the emergency generator set or otherwise by using a Diesel Engine

Driven.

4.5.2.21.All Fuel Supply should be adequate for minimum 2 hours of

continuous mode of operations.

4.5.2.22.Batteries for the Diesel Engine driven type of Standby Pump should

maintenance – free type.

4.5.2.23.All electrical cabling to Supply Power the Wet Riser Pumps should be

of MICC or Fire Rated Cable Type.

4.5.2.24.All Wet Riser Pump – Sets should be protected away from fire and

flooded areas.

4.5.2.25.A Sump Pump need to be considered for any special case of that

Wet Riser Pump – Sets to be located at the basement below the

external drainage levels. This Wet Riser Pump – Sets room also need

to be naturally or mechanical ventilated with a necessary signage

and to provide a CO2 – Portable Type of Fire Extinguisher for any

case of fire.

4.5.2.26.Effective Capacity of the Wet Riser Tank need to be sized up to

minimum capacity of 45,500 liters (10,009 Imp. Gallon) c/w

automatic refill rate of 455 lit/min (100.1 Igpm).

4.5.2.27.The Intermediate Break Tank for upper stages of the Wet Riser

should be sized up to a minimum effective capacity of 11,375 liters



(2503 Imp. Gallon) c/w automatic refill rate of 1365 lit/min (300.3

Igpm).

4.5.2.28.Wet Riser Tank Materials are usually from a Pressed Steel, Fibre

Reinforced Polyester (FRP) and Reinforced Concrete (R.C)

4.5.2.29.Pressed Steel – Wet Riser Tank should be Hot Dipped Galvanised and

Coated Internally with Bituminous paint for corrosion protection.

4.5.2.30.Both Pressed Steel and FRP – Wet Riser Tank need to be

compartmented unless they are Reinforced Concrete (R.C) and all

compartmented wet riser tanks need to provide with a separate Ball

Float Valves, Overflow Pipes, Drain Pipes and Water Level Indicator.

4.5.2.31.All Wet Riser Tank need to be painted red or else a red band of

minimum 200mm should be painted to indicate that this is a fire

tank.

4.5.2.32.All Wet Riser Tank could located on the Ground Floor, 1st.Lower

Ground Floor or 2nd.Lower Ground Floor level.

4.5.2.33.Wet Riser Tanks are usually separated from the Domestic Water

Storage/Suction Tanks but however could be combined with Hose

Reel Tank and need to be compartmented.

4.5.2.34.Pump Starter Panel should be complete with indicator lights as

shown at the appendix – a.

4.5.2.35.All types of ventilation slots should be provided with insect screen to

prevent entry of vermin (small insects; i.e. ants, spiders and etc.)

4.5.2.36.Power Supply cables to the panel should be of mineral insulated

copper cable (MICC) or fire rated type of cables within areas with low

risk.

4.5.2.37.The Fire Pump Starter panel should be placed within the same room

as the fire pumps it controls.

4.5.2.38.Wet Riser Pumps need to be automatically started upon actuation of

the pressure switches but should only be stopped manually. Usually

three pressure switches are provided with the following suggested

pressure settings:

starting the duty pump – set : 80% of the system pressure



starting the standby pump – set: 60% of the system pressure

starting and stopping the jockey pump – set at 90% and 110% of

the system pressure respectively.

4.5.2.39.Testing requirements for the Wet Riser System are the following;

Static Pressure Test – to clear up the debris from the inside of

Those main wet risers and hydraulically the pressure to be tested

up to 14 Bars or 150% the WorkingPressure, whichever is the

higher for 2 hours, measured at the lowest landing valve and a

check is carried out for leakage at all joints and landing valve

connections.

Flow Test – A three way of landing valve should be provided on

the roof or topmost floor for testing purposes where the main

motif is to measure the water flow rates



4.6. Downcomer System –






4.6.2. Design Method of Downcomer System;

4.6.2.1. It should be complied with UBBL 1984, relating to Downcomer

systems is the 10th.Schedule and relevant standards for Downcomer

systems as above mentioned.

4.6.2.2. Downcomers are a form of internal hydrant and are only required for

buildings where the topmost floor is not higher than 60 meters

above the fire appliance access level and should be adopted for low

cost flats only.

4.6.2.3. Downcomer system comprises a high level water storage tank

discharging into a 150mm dia. Riser pipe with landing valves at each

floor and to which canvas hose with nozzles can be connected to

direct the water jet at the fire.

4.6.2.4. No pumps are provided and therefore the system pressure is limited

to the static pressure head only.

4.6.2.5. Landing Valves are provided on each floor and should comply with

M.S 1210: Part 2.

4.6.2.6. Those Landing Valves would be located within the fire access

lobbies, protected staircases or other protected lobbies at not more

than 0.75 meters from the floor level.

4.6.2.7. A Semi – rigid 40mm diameter hose and nozzles should be provided

at every landing valve on each floor.

4.6.2.8. In addition, two sets of fire hose of the canvas type of not less than

38mm diameter, 30 metres in length complete with 65mm dia. quick



coupling and jet and spray nozzle should be provided at the

caretakers unit or property management office.

4.6.2.9. Fire Hose Reel Pipings > 38mm dia., 30 meters in length, complete

with 65mm dia. Quick Coupling and nozzle should be provided at

each landing valve.

4.6.2.10.A 4 - Way type of Breeching Inlet would be installed at the bottom of

the riser and should comply with M.S. 1210: Part 3. The breeching

inlet is enclosed within a box, the enclosure should comply with

M.S.1210 Part 5 and labeled ‘Downcomer Inlet’ and a typical drain

should be provided at the bottom of the riser to drain the system

after used.

4.6.2.11.This Breeching inlet should be located at no more than 18 metres

from the fire appliance access and not more than 30 metres from

the nearest external hydrant.

4.6.2.12.A Check Valve need to be installed between the topmost landing

valve and the tank to prevent any backflow of water from the

Downcomer into the tank.

4.6.2.13.The Downcomer mains are usually located within smoke free lobby

or protected areas and that all spaces are to be within 45 metres

coverage from a landing valve.

4.6.2.14.If more than 60 metres, so then need to have more than one riser is

required for each floor.

4.6.2.15.The Riser Pipe size should be 150mm and the material of the Riser

Pipe shall be Galvanised Iron to B.S. 1387 (heavy gauge) or Class C,

tested to 21 Bars (305 Psi)

4.6.2.16.All feeding Pipe-works that runs horizontally need to be sloped to

enable proper draining after used and also an Air Release Valve

should be installed at the top of the riser to relief air trapped in the

system.

4.6.2.17.All Downcomer pipes should be coated with primer and finished with

red gloss paint or otherwise can be colour coded with red bands of

100mm width and the elbows and tees painted red.

4.6.2.18.The riser pipe should be electrically earthed or connected to the

building earth to achieve equipotential.



4.6.2.19.The riser to be hydraulically tested to a pressure of 14 Bars for 2

hours that to be measured at the Breeching inlet and not forget to

check all leakage at the joints and landing valves connections.



4.7. Automatic Sprinkler System –


– BS EN 12845: 2003 – Automatic Sprinkler Systems – Design, Installation

and Maintenance.

– NFPA 13

Both above standards need to be followed unless the specific aspect is not

covered in the selected standard.

4.7.2. Design Method of Automatic Sprinkler System;

4.7.2.1. It should be complied with UBBL 1984, the by Laws 226 and 228

4.7.2.2. An Automatic Sprinkler System is designed for having a response to

detect, control and extinguishes a fire, and warned the occupants of

the occurrence of fire.

4.7.2.3. Basic mechanical installations for the Automatic Sprinkler System

are such as like Fire Pumps, Water Storage Tanks, Control Valve

Sets, Sprinkler Heads, Flow Switches, Pressure Switches, Pipe –

works and valves. This system operates automatically without

human intervention.

4.7.2.4. The Sprinkler Head usually has a liquid filled glass bulb that breaks

due to heat of the fire and releases water that sprays over the fire.

4.7.2.5. There are various types of Sprinkler Systems are as follows;

Wet Pipe installation – ready filled up with water and discharge

once the sprinkler bulb breaks

Dry Pipe installation – always filled up with air under pressure

and air is released once the sprinkler bulb breaks then only the

water fills the pipe and is discharged at the sprinkler head.

Pre–action installation – normally charged with air unde pressure

and a valve is opened to fill the system with water when fire is

detected by smoke or heat detectors and also when the sprinkler

bulb breaks.



Deluge Installation – the sprinkler head has no bulb and water is

discharged simultaneously from all heads when fire is detected

and the deluge valve is open



4.8. Occupancy Hazards Groups:

4.8.1. Light Hazards : Non–Industrial occupancies with low quantity and

combustibility contents, e.g. apartments, schools and hospitals.

4.8.2. Ordinary Hazards : Commercial and Industrial occupancies in which By

handling and storing ordinary combustible materials and group under the

followings;

4.8.2.1. OH Group I for offices, restaurants and hotels,

4.8.2.2. OH Group II for laundries, bakeries and tobacco factory,

4.8.2.3. OH Group III for car parks, departmental stores, large retail shops

and cinemas, clothing and paint factories and

4.8.2.4. OH Group IIIS for match factories, film and television studios.

Note:

- for high rise buildings with multiple type of occupancies, the hazard class

recommended is OH Group III

4.8.3. High Hazards : Commercial and Industrial occupancies in which By handling

and storing the abnormal fire loads covering process hazards, high piled

storage hazards, oil and flammable liquid hazards and group under the

followings;

– Process Risk, e.g. clothing, rubber, wood wool and paint factories High

Piled Storage risk could be categorised into four (4) categories;

Category I – Carpets and textile exceeding 4 meters in height,

Category II – furniture factory piled above 3 meters,

Category III – rubber, wax coated paper piled > 2m and

Category IV – for foam, plastics piled > 1.2m.

4.8.4. Sprinkler Pump Requirements;

4.8.4.1. Normal Standard



One (1) unit on Duty, One (1) unit on Standby and One (1) of

Jockey Pump to maintain the system pressure.

4.8.4.2. The nominal pressure and flow requirements under all types of

hazards are as the followings;

Light Hazard

15 meters: flow - 0.3 m³/min and at operating pressure of 1.5

bars

30 meters: flow - 0.34 m³/min and at operating pressure of

1.8 bars

45 meters: flow - 0.375 m³/min and at operating pressure of

2.3 bars

Ordinary Hazard Group I

15 meters: flow – 0.9 m³/min and at operating pressure of 1.2

bars

30 meters: flow – 1.15 m³/min and at operating pressure of

1.9 bars


2.7 bars



Ordinary Hazard Group II


1.4 bars


2.0 bars


2.6 bars

Ordinary Hazard Group III


1.4 bars


2.0 bars


2.5 bars

Ordinary Hazard Group IIIS


1.9 bars


2.4 bars



4.8.5. Notes for Mech. Engr.’s –

4.8.5.1. for Building exceeds 45m than the multiple stage of sprinkler

installations should be implemented. This would be able to serve the

full height of the building with each stage not exceeding 45 meters.

4.8.5.2. A standby Sprinkler Pump – Set should be supplied with power from

the emergency generator or else need to use a diesel engine driven.

All Diesel Oil Supply could withstand 4 hours – Ordinary Hazards and

6 hours for High Hazard applications.

4.8.5.3. All Electrical Cabling to supply the power to the Sprinkler Pumps

should be a fire rated cable type or MICC. Batteries for the diesel

engine also need to be a maintenance – free type

4.8.5.4. All Sprinkler Pumps that protecting the high rise buildings need to

consider the static pressure between the pump and the lowest

sprinkler head by adding up to the above pump pressure

requirement.

4.8.5.5. All Sprinkler Pumps should be under positive head as far as possible,

protected from fire and flooded areas. Sump Pump could

be considered if this Sprinkler Pump to be located at the Basement

below the the external drainage levels. As usual this Pump Room

that located at the basement need to be naturally / mechanical

ventilated c/w a necessary signage and must also provide a CO2 –

Portable Extinguisher.

4.8.5.6. All Sprinkler Pump Starter Panels and Controls should

be Compartmented for each duty, standby and jockey pumps c/w

indicator lights as shown in the figure 11.2 (as per the attachments

at apprendix – A).

4.8.5.7. As normal practice all Fire Fighting Pump room need to provide with

an insect screen to prevent entry of vermin (e.g. insects, flies,

cockroach and etc.) and the location of Pump Starter Panel should

be placed at the same room as the fire pumps it controls.

4.8.5.8. Usually three pressure switches are provided with the following

Suggested pressure settings:

starting the duty pump – set : 80% of the system pressure

starting the standby pump – set: 60% of the system pressure



starting and stopping the jockey pump – set at 90% and 110% of

the system pressure respectively.

4.8.5.9. Electrical interlocks should be provided so that the sprinkler pumps

at each installation would not operate in parallel simultaneously and

a buzzer should be sounded and the isolator should be in the off or

manual position.

4.8.5.10.All Sprinkler Pump – Sets should be able to start automatically and

stop manually.

4.8.5.11.Sprinkler Fire Tanks –

4.8.5.11.1. Light Hazard

15 meters: flow - 9 m³ (1980 Imp. Gallon)



4.8.5.11.2. Ordinary Hazard Group I

15 meters: flow - 55 m³ (12,100 Imp. Gallon)





4.8.5.11.3. Ordinary Hazard Group II




4.8.5.11.4. Ordinary Hazard Group III




4.8.5.11.5. Ordinary Hazard Group IIIS


30 meters: flow - 185m³ (40,700 Imp. Gallon)

4.8.5.11.6. High Hazard

Storage Capacity shall be dependent on the design

density of discharge in mm/min

4.8.5.12.It is noted for all Mechanical Engineer’s to read and understand all

other standard & procedures that required from the latest Fire

Protection Services (Second Edition – 2006) at Chapter 11, 12, 13,

14, 15 till Chapter 20.

4.8.5.13.Design reference from last and current projects.



A Basic Design Guideline for Mechanical Engineering Systems Could Be Categorised Into Five (5)...

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