HomeMy WebLinkAboutSP201800001 Approval - Hydraulic Modeling Analysis 2019-01-16 •
HYDRAULIC MODELING ANALYSIS CERTIFICATION
I hereby certify that the hydraulic modeling analysis for:
Keswick Hall Water System Expansion
(Project Name)
Keswick Estates Waterworks
(Water System Name)
2003400
(Water System Numbet)
supports the proposed design. The proposed additions/modifications to the
distribution system will not cause the pressures at any new or existing connections
to be less than those specified in 12VAC5-590-690 of the Waterworks Regulations.
The model is sufficiently calibrated and accurate to represent the operating
conditions of the water distribution system.
The hydraulic modeling method used: Computer Software- Steady State Model
(e.g. computer software—extended period simulation, steady state model, or manual calculation)
the computer software used: Bentley WaterGEMS V8i
(software name and version)
41tiALTH op
Grc
6 BRUCE W.
U STRICKLAND JR. a
Signatures.r Lic.No.056612
Full Name: Bruce W. Strickland, Jr. , PE o �v
� 8I0NAL ,.40\
Date: 1/18/19
(*This page must be signed,sealed,and dated by a professional engineer who oversees the completion of
this hydraulic modeling analysis.)
Hydraulic Model Data Summary
Brief Description of Project: Expansion of the Keswick Estates Waterworks to provide
additional permitted capacity.The project will include a new well, new 22,000 gallon atmospheric
storage tank, and duplex 250 gpm minimum booster pumps.The existing 6,000 gallon
hydropneumatic tank will be replaced in kind.
Hydraulic Model Input Summary:
❑ Entire distribution system is modeled
❑ Part of the distribution system is modeled
g Node map is provided(plan sheet C5.0)
If only part of the distribution is modeled,what is the basis for model development:
O Hydrant flow test: gpm @ psi residual pressure
❑ Gravity from storage tank: water surface elevation feet
g Other: Hydropneumatic tank pressure set points of 75 psi and 95 psi to demonstrate typical
system pressures while also maintaining a minimum residual pressure of 40 psi
during peak hour demands.
Residential Water Demand: Q= 187.5 gpd per household
Based Upon ❑ Census data x gpcd •
g Historical Usage Data
❑ Other:
Commercial and Industrial Demand: 42,125 gpd, or gpm
Total Demand: Qavg= 45.4 gpm •
Maximum Day Demand: Qavg x 1.6 peak factor = 72.6 gpm
Based Upon: 0 2.0 peaking factor
g Other: Historical usage data
Peak Hour Demand: pays x 5.5 peak factor = 250 gpm
Based Upon: 0 4.0 peaking factor
g Other: VDH 12VAC5-590-690 Max Hour Domestic Demand Formula:
0=11.4*N^0.544 = 11.4*(104,600/400)^0.544= 236 (rounded to 250)
Is fire protection included in the project: ❑Yes g No
If Yes,Design fire flow and duration: gpm for hours
Page 1 of 3
Does the project include gravity storage? I'Yes ❑ No
(If more than one tank is included in the model,provide additional tank information on attached
sheets.)
If Yes, Storage tank nominal capacity: 58,000 gallons
Tank overflow elevation: 413.0 feet
Tank base elevation: 403.0 feet
Typical tank control low elevation: 404.0 feet
Typical tank control high elevation: 412.5 feet
`Note:gravity storage is not included in the model.
Does the project include pumps? gYes ❑ No
(If more than one pumping station is included in the model,provide additional tank information
on attached sheets.)
If Yes, Number of pumps provided: 2
Single pump capacity: 350 gpm @ 239 feet TDH
Combined pump capacity: 620 gpm @ 264 feet TDH
*Note: booster pumps are not included in the model.
Has the model been calibrated based on actual hydrant testing? ❑ Yes d No
Pipe material: Ductile Iron
Pipe Roughness Coefficient: C= 120
Hydraulic Model Output Summary:
Peak Flow Evaluation:
The model output must demonstrate that a 20 psi minimum pressure can be maintained at all
locations during peak hour demand or maximum day demand plus a simultaneous fire flow event,
whichever is greater. Typically,the starting tank elevation should be the normal low tank level.
The model should perform an extended period simulation to run through the entire designated fire
flow event(i.e., 500 gpm for 2-hours) during max day demand. A simple snap shot of max day+
fire flow at the beginning of the fire duration may be appropriate in simple models. Model must
also assign a node and appropriate demand at the highest elevation.
Reports submitted: d Junction Report for Max Day+Fire Flow
—►(or peak hour if greater)
d Pipe Report for Max Day+Fire Flow
(or peak hour if greater)
IR! Tank Report,as needed(Hydropneumatic)
❑ Pump Report, as needed
❑ - Fire Flow Report(in lieu of Junction Report)
Critical Node Output:
Node Identification: J-11 Node Elevation: 446 feet
Flow: 161 gpm Pressure: 47 psi
Page 2 of 3
Effective Storage Evaluation:
Available effective storage is determined based on the minimum storage tank water surface
elevation necessary to maintain a minimum pressure of 20 psi at all locations in the distribution
system during maximum day flow.
Reports submitted: g Junction Report for Max Day
d Pipe Report for Max Day
C� Tank Report (Hydropneumatic)
❑ Pump Report, as needed
*Note: Reports are provided for Peak Hour, not Max Day
Critical Node Output:
Node Identification: , J-11 Node Elevation: 446 feet
Flow: 161 gpm Pressure: 47 psi.
Storage Tank Identification: Hydropneumatic Tank
(If more than one tank is included in the model,provide additional tank information on attached
sheets.) peak hour
Minimum elevation necessary under maximum-day domestic flow: 573.26 feet
Overflow elevation: N/A feet
Tank bottom elevation: N/A feet •
Effective storage volume: 2,000 gallons
Notes:
1. Gravity storage tanks are not included in the model.
2. Booster pumps are not included in the model.
3.Junction, Pipe, and Tank Reports are provided for the Peak Hour scenario, not the Max Day.
4.The minimum hydropneumatic tank setting of 75 psi provides a minimum pressure of 40 psi
throughout the distribution system during peak hour flow.
5. A new 22,000 gallon atmospheric storage tank will be provided, bringing the total effective
storage volume to 60,000 gallons.
6. Well Pump and Booster Pump Performance Curves are attached.
7. Hydropneumatic Tank Design Calculations table is attached.
Page 3 of 3
Scenario: Peak Hourly Demand - Low HGL
Current Time Step: 0.000 h
FlexTable: Junction Table
Label Elevation Demand Hydraulic Pressure
(ft) (gpm) Grade(ft) (psi)
J-1 400.81 0.0 573.12 74.6
J-2 393.52 0.0 571.82 77.1
J-3 422.68 4.3 562.34 60.4
J-4 419.51 4.3 561.37 61.4
J-5 392.09 4.3 560.42 72.8
J-6 361.01 2.1 558.98 85.7
J-7 361.10 4.3 558.54 85.4
J-8 372.77 5.0 557.63 80.0
J-9 409.47 5.0 556.43 63.6
J-10 433.53 0.7 555.48 52.8
J-11 446.01 160.9 554.56 47.0
J-12 423.79 3.6 556.70 57:5
J-13 410.98 4.3 557.59 63.4
J-14 425.20 2.9 557.59 57.3
J-15 404.72 3.6 558.78 66.7
J-16 404.03 4.3 558.67 66.9
• J-17 371.37 4.3 558.66 81.0
J-18 393.82 5.7 559.47 71.7
J-19 401.52 2.9 559.46 68.3
J-20 415.34 5.0 559.46 62.4
J-21 408.80 3.6 559.46 65.2
J-22 403.91 4.3 559.95 67.5
J-23 376.27 4.3 560.40 79.7
J-24 428.40 4.3 561.22 57.5
J-25 412.35 2.1 561.52 64.5
J-26 419.16 3.6 561.93 61.8
L:\201\40241 -Keswick Water and Sewer\Calc\Water\Model\2018-12-28\40241-MODEL_2018-12-28.wtg
Scenario: Peak Hourly Demand-Low HGL
Current Time Step: 0.000 h
FlexTable:,Pipe Table
•
Start Diameter Hazen- Flow Velocity Hydraulic Hydraulic Headless
Label Length(ft) Node Stop Node (in) Williams C (gpm) (Ws) Grade Grade Gradient
(Start)(ft) (Stop)(ft) (MO
P-1 198 J-1 J-2 6.0 120.0 249.5 2.83 573.12 571.82 0.007
P-2 1,442 J-2 J-3 6.0 120.0 249.5 2.83 571.82 562.34 0.007
P-3 1,150 J-3 J-4 8.0 120.0 175.2 1.12 562.34 561.37 0.001
P-4 1,207 J-4 J-5 6.0. 120.0 79.4 0.90 561.37 560.42 0.001
P-5 2,015 J-5 J-6 6.0 120.0 75.2 0.85 560.42 .558.98 0.001
P-6 650 J-6 1-7 6.0 120.0 73.0 0.83 558.98 558.54 0.001
P-7 817 J-7 J-8 6.0 120.0 95.7 1.09 558.54 557.63 0.001
P-8 1,191 J-8 J-9 6.0 120.0 90.7 1.03 557.63 556.43 0.001
P-9 1,048 1-9 J-10 6.0 120.0 85.7 0.97 556.43 555.48 0.001
P-10 314 J-10 J-11 6.0 120.0 160.9 1.83 555.48 554.56 0.003
P-11 1,688 1-10 1-12 6.0 120.0 -75.9 0.86 55548 556.70 10.001
P-12 1,128 1-12 1-13 6.0 120.0 -79.5 0.90 556.70 557.59 0.001
P-13 851 J-13 J-14 6.0 120.0 2.9 0.03 557.59 557.59 0.000
P-14 1,288 J-13 1-15 6.0 120.0 -86.6 0.98 557.59 558.78 0.001
P-15 651 J-15 J-16 6.0 120.0 35.6 0.40 558.78 558.67 0.000
P-16 1,190 J-7 J-16 6.0 120.0 -27.0 0.31 558.54 558.67 0.000
P-17 1,064 1-18 J-17 6.0 120.0 4.3 0.05 558.67 558.66 0.000
' P-18 1,494 J-15 1-18 8.0 120.0 -125.8 0.80 558.78 559.47 0.000
P-19 907 J-18 1-19 8.0 120.0 11.4 0.07 559.47 559.46 0.000
P-20 785 J-19 J-20 8.0 120.0 8.6 0.05 559.46 559.46 0.000
P-21 611 1-20 J-21 8.0 120.0 , 3.6 0.02 559.48 559.46 0.000
P-22 842 1-18 1-22 8.0 120.0 -142.9 0.91 559.47 559.95 0.001
P-23 735 1-22 J-23 8.0 120.0 -147.2 0.94 559.95 56040 0.001
P-24 1,279 1-23 1-24 8.0 120.0 -151.5 0.97 560.40 561.22 0.001
P-25 587 J-4 J-24 8.0 120.0 91.4 0.58 561.37 561.22 0.000
'P-26 561 J-24 J-25 6.0 120.0 -64.4 0.73 561.22 561.52 0.001
P-27 713 1-25 J-26 6.0 120.0 -66.5 0.75 561.52 561.93 0.001
P-28 656 J-26 J-3 6.0 120.0 -70.1 0.80 561.93 562.34 0.001
P-29 21 HT-1 J-1 6.0 120.0 249.5 2.83 573.26 573.12 0.007
LA201\40241-Keswick Water and Sewer\Calc\Water\Model\2018-12-28140241-MODEL_2018-12-28.wtg
Scenario: Peak Hourly Demand - Low HGL
Current Time Step: 0.000 h
FlexTable: Hydropneumatic Tank Table
Volume
Label Elevation(ft) HGL Off(ft) HGL On (ft) HGL (Effective) Volume
(Initial)(ft) (gal) (Tank)(gal)
HT-1 400.00 619.45 573.25 573.26 2,000.0 6,000.0
L:\201\40241 -Keswick Water and Sewer\Calc\Water\Model\2018-12-28\40241-MODEL_2018-12-28.wtg
Keswick Well #5 Pump Performance Curves
Upper System Curve ---- Lower System Curve Goulds 65GS50
450.0 1 1 -
400.0 1 --
350.0 l �
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300.0
250.0 _
-ci - ill _,
to
cu
200.0 —
150.0 — --- —
100.0
i
50.0
0.0 1 [ _
0 10 20 30 40 50 60 70 80
Flow,gpm
Keswick Booster Pump Performance Curves
—Upper System Curve —Lower System Curve --Goulds eSV
—53.6 Hz Reduced Speed Pump Curve —Combined Pump Curve —Combined Reduced Speed
350.0
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50.0 --
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0 100 200 300 400 500 600 700 800 900
Flow,gpm
Hydropneumatic Tank Design Calculations
Tank Dimensions (Alas)Design Pressures(psi) Pump Cycle This is the actual low pressure which will be seen if the
Len Dia Vol(gal) Hi Lo Min Gallons Low Pressure r minimum pump cycle volume is used to set the pump on
28.37 6 109.7 89.7 800 91 I and pump off levels,and the Selected HWL(under
"Compressor Design")is used.
Max VoIH2o(HWL) <--PVa„--> Vol @ 89.7psi HWL(in) LWL(in) Range(in) Gal Stored excess Stored Pump Design
50% 1551 39% 36.0 28.4 7.6 669 331 Pump Q 320 gpm
49% 1582 38% 35.4 27.8 7.6 682 2,2 Starts/Hour 6
48% 1613 36% 34.9 27.2 7.6 696 2,184 Min Cycle 10.00 Min.
47% 1644 35% 34.3 26.7 7.6 709 2.111
7hese are the available storage volumes between
46% 1675 34% 33.7 26.1 7.7 722 2,038 the Hi and Lo design pressures,given the
45% 1706 33% 33.2 25.5 7.7 736 1,964 corresponding HWL setting listed at the left. If
44% 1737 32% 32.6 24.9 7.7 749 1,891 the volume is not enough to give the desired
43% 1768 30% 32.0 24.3 7.7 763 1,817 ipumo cycle,it is craved out.
470/, 1799 29% 31.5 23 7 7.8 776 1,744
1830 28% 30.9 7.8 789 1,671
40% 1861 27% 30.3 22.5 7.8 803 1,597 Compressor Design
39% 1892 25% 29.7 21.9 7.9 816 1,524 Run Time 15 Min.
38% 1923 24% 29.2 21.3 7.9 829 1,451 HWL Min 108 psi
37% 1954 23% 28.6 20.6 8.0 843 1,377 Selected HWL 34%
36% 1985 22% 28.0 20.0 8.0 856 1,304 Air @ Hi psi 0.56 cfm
35% 2016 21% 27.4 19.4 8.1 870 1,230
34% 2047 19% 26.9 18.7 8.1 883 1,157
33% 2078 18% 26.3 18.1 8.2 896 1,084
32% 2109 17% 25.7 17.4 8.3 910 1,010
31% 2140 16% 25.1 16.8 8.3 923 937
30% 2171 14% 24.5 16.1 8.4 936 864
29% 2202 13% 23.9 15.4 8.5 950 790
28% 2233 12% 23.3 14.7 8.6 963 717
27% 2264 11% 22.7 14.0 8.7 977 643
26% 2295 10% 22.1 13.3 8.8 990 570
25% 2326 8% 21.5 12.5 8.9 1,003 497
24% 2357 7% 20.8 11.8 9.1 1,017 423
>>> 23% 2388 6% 20.2 11.0 9.2 1,030 350
VoIH20(HWL)is an independent variable.
HWL(in)is the water depth at the given VoIH2o(HWL)
PVa,r is the Boyle's Law constant(=P1V1=P2V2)which is the same for all tank depths
Vol @ 89.7psi is the tank volume at which the design minimum pressure will occur
LWL(in)is the water depth to be used for Pump Cycle LWL design
Range(in)is the difference in HWL and LWL(based on Pump Cycle LWL design)
Gal Stored is the total volume available between the Hi and Lo Design Pressures
Excess Stored is the amount of water left in the tank when the Lo Design Pressure is reached
RECEIVED
FEB 0 6 ',q,::
COMMUNITY
DEVELOPMENT