TECHNOLOGICAL UNIVERSITY (THANLYN)
Department of Mechanical Engineering
Design Calculation of Plumbing
and Sanitary System for Six
Storyed Building
First Seminar
25 .7 .2025
Presented by
Supervisor Wai Yan Phyo
Dr. Daw May Kyi Thar VI Mech-79
Outline of Presentation
• Introduction of Plumbing and Sanitary System
• Aim and Objectives
• Implementation Program
• Design Consideration of Plumbing and Sanitary System
Introduction of Plumbing and Sanitary
System
• Water Sources
• Water Supply System
• Utilization of water in domestic plumbing fixture
• Pumping System
• Sanitary Drainage System
• Sewage System
• Types of waste water
• Types of Stack System
Aim and Objectives
To design the plumbing and sanitary system for six storied hospital building.
• To calculate the water demand
• To calculate underground water tank size
• To calculate overhead water tank size
• To calculate transfer pump size
• To calculate booster pump size
• To calculate water supply pipes size
• To calculate septic tank size
• To calculate soil and waste water pipe
Implementation Program
• Studying the literature and theories of Plumbing and Sanitary System
• Consideration of building design and design specification
• Searching and collecting data requirements for the selected design
• Detailed design of water supply system
• Design of drainage system
Water Source
• City water supply (infrastructure)
Eg .YCDC,PUB
• From Ground water
Eg .Tube Well,Bore Well
• From river , lake ,dam
Calculation of water demand
For the total number of people in the six storied hospital building,
By the reference of MNBC,
1 BED =2 persons
1 person = 150 L/day
Ground Floor , 5 BEDs =10 persons
2nd Floor , 14 BEDS=28 persons
3rd Floor , 14 BEDS=28 persons
4th Floor , 14 BEDS=28 persons
5th Floor , 14 BEDS =28 persons
Number of staff =50 persons
Water Demand = (10+28+28+28+28+50)x150 =24300 L/day
=24 m3
Water demand 24
Volume of water tank = = =30 m3
Full fill capacity 0.75
Calculation of underground tank
Design consideration of two compartments for underground tank
Volume of underground tank T2 (2 compartment) =2x30 ( for 2 days)
= 2x30 =60m3
Volume of each tank size =30m3
Design the height of tank ,H=2m
V=AH
A=V/H =30/2=15m2
Assuming B=L ,
B xL =15 m2
B=L=4m
Tank size,
H=2 m
B=L=4m
Calculation of Overhead Tank
Volume of Overhead Tank = 30 m3 (for 1 day)
For over head tank type T1(2 compartment)
volume of tank size = 30 m3 (15 m3 for each tank)
For Tank T1,
Design the height of water tank =2 m
V=AH
A=V/H
=15/2=7.5m2
We will consider , B=L
Where, B= bread ,L=length
BxL=7.5 m2
B=L=2.7 m~ 2.5m
Tank size,
H=2m
B=L=2.5m
Calculation of branch pipe size for
ground floor
From table 4.1 , by the reference of CP48,
We got the loading unit value for domestic fixtures
WC (water closet)= 2
WB (water basin) = 1.5-3
Urinal =1
Shower =3
For ground floor level,
Number of water closet=9
Number of water basin =9
Number of urinal =3
Number of shower =2
TLU =2(9)+1.5(9)+1(3)+3(2)=40.5
From the loading unit and design flow rate chart (CP48),
Qp1 =0.68 L/s
Design Velocity ,v =1.25 m/s (CP48)
By constant velocity method,
Q =Av
A=Q/v
π/4 d2 =0.68/1.25 =0.54x10-3
d2 =0.68x10-3
d =0.026 m=26mm =25 mm (standard size)
Calculation of branch pipe size for first floor
From table 4.1 , by the reference of CP48,
We got the loading unit value for domestic fixtures
WC (water closet)= 2
WB (water basin) = 1.5-3
Urinal =1
Shower =3
For first floor level,
Number of water closet=2
Number of water basin =2
Number of shower =2
TLU =2(2)+1.5(2)+3(2)=13
From the loading unit and design flow rate chart (CP48),
Qp1 =0.37 L/s
Design Velocity ,v =1.25 m/s (CP48)
By constant velocity method,
Q =Av
A=Q/v
π/4 d2 =0.37/1.25 =0.3x10-3
d2 =0.38x10-3
d =0.02 m=20mm =25 mm (standard size)
Calculation of branch pipe size for
second floor
From table 4.1 , by the reference of CP48,
We got the loading unit value for domestic fixtures
WC (water closet)= 2
WB (water basin) = 1.5-3
Urinal =1
Shower =3
For second floor,
Number of water closet=13
Number of water basin =13
Number of shower =13
TLU =2(13)+1.5(13)+3(13)=84.5
From the loading unit and design flow rate
chart (CP48),
Qp2 =1.1 L/s
Design Velocity ,v =1.25 m/s (CP48)
By constant velocity method,
Q =Av
A=Q/v
π/4 d2 =1.1/1.25 =0.88x10-3
d2 =1.12 x10-3
d =0.03 m=26mm =25 mm (standard size)
Calculation of transfer pump size
Water volume of overhead tank =26 m3
Refill time =2hr
Storage water volume of overhead tank
Transfer pump flow rate =
Tank refill time
26 m3
2hr x 3600s
=3.6x10-3 m3 /s
Assume velocity , v=1.5 m/s , Q =Av
A =Q/v
3.6x10-3
A=
1.5
A=2.4x10-3
d2= 3x10-3
Diameter of transfer pump , d=54 mm =50mm(standard size)
Static head =Suction head +Discharge head
Hs = 1.37+ 4.5(6) +2 =30.37
Straight pipe length = 30.37 +1.2+1.8+5.4=38.77m
For transfer pump,
Gate valve =2
Check valve =2
Elbow =6
From table A3, for d=50mm=2in
Equivalent pipe length =2x1.38+2x17.2+6x5.17
=68.18 ft =20.5 m
Effective pipe length =straight pipe length +equivalent pipe length
Lt =38.77+20.5=59m
By Hazen Willian Equation,
10.67xQ1.852 x Lt
Hf =
1.852 4.8704
10.67x(3.6x10-3 )1.852 x59
Hf =
1501.852x504.8704
=3.8 m
Residual loss, Hr = 10%(Hs +Hf)
=0.1(31.5 +3.8)=3.64
Pump head, H =Hr+Hs+Hf
H=3.64 +31.5+3.9 =40 m
ꝬgQH
Pump Power =
ηpumpηmotor
1000x9.81x40x3.6x10-3
=
0.8x0.75
=2354.4 W =2.3 kW = 3HP
Calculation of booster pump
Number of water closet=39
Number of wash basin =39
Number of shower =39
Total loading unit of fixtures =(52x2)+(52x1.5)+(52x3)=338 (CP48)
From loading unit and design flow rate chart, Q =2.55 L/s
Q= Av
v=1.25 m/s ( Design velocity )
A = Q/v
π/4 d2 = 2.55/1.25 =2.04
d =0.050mm =50mm (standard size)
Static head =Suction head +Discharge
head
Hs = 1.4+3(4.5) =14.9m
Straight pipe length = 14.9 +2.7+5.4=23 m
For transfer pump,
Gate valve =4
Check valve =2
Elbow =4
From table A3, for d=50mm=2in
Equivalent pipe length =4x1.38+2x17.2+4x5.17
=60.6 ft =18.5 m
Effective pipe length =straight pipe length +equivalent pipe length
Lt =23+18.5=41.5m
By Hazen Willian Equation,
10.67xQ1.852 x Lt
Hf =
C1.852xd4.8704
10.67x(2.55x10-3 )1.852 x41.5
Hf =
1501.852x504.8704
=3.45 m
Residual loss, Hr = 10%(Hs +Hf)
=0.1(14.9+3.45 )=1.83m
Pump head, H =Hr+Hs+Hf
H=1.83+14.9+3.45 =20.18m
ꝬgQH
Pump Power =
ηpumpηmotor
= 1000x9.81x20.18x2.55x10-3
0.8x0.75
=1 kW =1.34 HP
Reference
• Code of practice (CP 48)
• Myanmar national building code (MNBC)
• Handbook of PVC pipe design and Construction
• Hazen _ willian equation
Conclution
Underground tank size , H=2m ,B=L=4m
Overhead tank size ,H=2m ,B=L=2.5 m
Pipe size for ground floor ,d =25 mm
Pipe size for first floor ,d =
Pipe size for 2nd to 5th floor , d=
Transfer pipe size ,d =50mm
Booster pipe size ,d =50mm
Transfer pump power =2.3 kW
Booster pump power =1kW
Future Plan
To design the septic tank
To design the soil pipe
