This presentation illustrates a typical piping distribution system. In case the listener is interested in design service for a system of a similar or larger magnitude, he/she may contact at the following e-mail address.

1. Community Water Distribution
Piping Design

2. Common Shortcomings
• Water distribution piping in an apartment complex is
sometimes finalized without proper engineering
• Pipes and fittings available with regular erection
contractor are often used
• Improper sizes are selected for distribution piping
• Apartments further away from water supply sources
get penalized with water scarcity
• Unreliable manual regulation of valves becomes
inevitable to achieve equal water distribution
• Relationship between neighbors getting tarnished

3. Advised Check Points
• Larger pipe size for remote apartment inlets than the closer ones
• Progressively reduced header pipe size from pump outlet
maintaining optimum line velocity
• Conducting network flow analysis calculation to ensure fair
distribution
• For Closed Loops use of HARDY CROSS process
• Use of pressure breakdown orifices in preference to manual
globe/butterfly valves, if absolutely required
• Pump parameter selection criteria:
(a) Pump flow to be sufficient to replenish all consumers at a time.
(b) Pump Head should include:
• Static elevation change
• Frictional head drop in pipes, valves & fittings

4. Hypothetical Schematic Diagram
A
1
B
C
D
TANK
E
G
F
Q
O
3
R
P
M
K
N
J
I
H
L
2
Point Ref. Elevation
meters
1 -1.0
2 60.0
3 60.0
4 60.0
5 60.0
6 60.0
4
5
6
ELEVATION SCHEDULE
RESERVOIR
PUMPS
TANK
TANK
TANK
TANK

5. Notes On Illustration
• One Pump Operating, other Stand-by
• Valves and fittings not shown.
• Break-up calculation for equivalent length for
including effect of valves and fittings not
shown
• Pressure drop calculation by Hazen Williams
Formula.

6. Procedural Details
• Step 1
– Collect data on the following :
• Desired flow to each consumer
• Static elevation of pump inlet reservoir
• Static Elevation at each consumer’s storage reservoir
inlet
• Optimum piping route to be followed from pump house
to all consumer points

7. Procedural Details … cntd.
• Step 2:
– Make a preliminary selection of pipe sizes as per the
following guideline :
• Average velocity of 1-2 m/sec for pump suction
• Average velocity of 1.5-3 m/sec for pump discharge,
distribution header and consumption point inlet piping
• Step 3:
– Conduct a flow calculation assuming a preliminary
pump TDH and assigning desired flow for each
consumer inlet and flow in the distribution header as
required.

8. Procedural Details … cntd.
• Step 4:
• Note the deviation in the calculated pressure at the
consumption points from the desired pressure.
• Step 5:
– Conduct successive trials to narrow down the
deviation as in Step 4 as much as possible by varying
the following as required to get an optimum result :
• Pipe Size
• Flow to the consumption points
• Pump Head

9. Hypothetical Schematic Diagram
A
1
B
C
D
TANK
E
G
F
Q
O
3
R
P
M
K
N
J
I
H
L
2
Point Ref. Elevation
meters
1 -1.0
2 60.0
3 60.0
4 60.0
5 60.0
6 60.0
4
5
6
ELEVATION SCHEDULE
RESERVOIR
PUMPS
TANK
TANK
TANK
TANK

10. Hypothetical Example Data Table
INPUT DATA
0 1 2 3 4 5 6 7
Pipe Pipe Pipe Pipe Total Flow Pipe Pipe
Ref. NB
Outside
Diameter
Thickness Eqvt. Length Rate Inlet Height
Above Datum
Outlet Height
Above Datum
mm mm mm meters m3/hr. m m
AB 150 168.3 7.1 5 104.5 -1 0
BC 150 168.3 7.1 3 104.5 0 0
EG 125 141.3 6.6 4.5 104.5 0 1
GH 125 141.3 6.6 50 104.5 1 -1
HI 50 60.3 3.9 150 21.91 -1 60
HJ 125 141.3 6.6 100 82.59 -1 -1
JN 100 114.3 6 90 40.31 -1 -1
NO 50 60.3 3.9 150 19.78 -1 60
JK 100 114.3 6 120 42.28 -1 -1
KL 50 60.3 3.9 150 19.35 -1 60
NM 80 88.9 5.5 135 20.53 -1 -1
KM 80 88.9 5.5 110 22.93 -1 -1
MP 80 88.9 5.5 75 43.47 -1 -1
PQ 65 73 5.2 150 22.64 -1 60
PR 65 73 5.2 175 20.83 -1 60

11. Hypothetical Example Data Table
(Cont’d……..)
SUMMARY OF RESULTS
8 9 10 11
Pipe
Pipe Inlet
Pressure
Press.
Pipe Outlet
Pressure
Velocity
Ref.
Drop
Hazen
Williams,
mwc mwc mwc m/sec.
AB 0.00 0.10 -1.10 1.56 Pump Flow at Operating Condition = 104.5 Cu.m/Hr.
BC -1.10 0.06 -1.15 1.56 Pump TDH at Operating Condition = 99.15 mwc
EG 98.00 0.21 96.79 2.25
GH 96.79 2.37 96.41 2.25
HI 96.41 30.41 5.00 2.81
HJ 96.41 3.07 93.34 1.78
JN 93.34 2.19 91.15 1.36
NO 91.15 25.16 5.00 2.54
JK 93.34 3.19 90.15 1.43
KL 90.15 24.15 5.01 2.48
NM 91.15 3.55 87.60 1.20
KM 91.15 3.55 87.60 1.34
MP 87.60 7.91 79.69 2.53
PQ 79.69 13.71 4.98 2.04
PR 79.69 13.71 4.98 1.88

12. This presentation illustrates a typical piping
distribution system. In case the listener is
interested in design service for a system of a
similar or larger magnitude, he/she may
contact at the following e-mail address with
full technical details of the problem and
piping topography drawing in acrobat reader.
Commercial matters may be negotiated.
consultant.piping1@gmail.com
Thanks for listening

13. The End