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HomeMy WebLinkAboutFire Flow Conditions-4"O� vz-zrf '& ❑ ❑ Kimley-Horn and Associates, Inc. Technical Memorandum Suite 201 2800 Seulh Texas Avenue Bryan, Texas 77802 To: City of College Station From: J. Chris Harris, P.E. Date: April 24, 2012 Subject: The Stack Fire Flow Conditions KHA Project No. 067543000 Purpose The proposed development consists of mixed use development building on approximately 3.05 developed acres. This technical memorandum presents results of the water system analysis for the proposed development. This memorandum is divided into the following sections: • References and Design Criteria • Results • Conclusion References and Design Criteria References Water distribution mains throughout the development were sized by creating a hydraulic model of the system, using WaterCAD version 7.0 by Bentley Systems. The following data and references were used for creation of the model: Fire flow tests performed by College Station Utilities on December 28, 2011 near the proposed development site, attached as Appendix A. Design Criteria Water distribution mains were sized based on design criterialisted in the 2009 Bryan / College Station Unified Design Guidelines for Domestic Water. Design criteria used for this analysis includes: The Stack Water System Analysis April 24, 2012 Page 2 Peak Flow Conditions o Provide minimum static pressure of 35 pounds per square inch (psi). Fire Flow Conditions o Provide the required fire flow at the most hydraulically remote pairings of 2 adjacent fire hydrants in the system improvement in addition to the peak hourly flow. o A residual pressure of 20 psi is required to be maintained. o Velocity shall not exceed 12 feet per second (fps) The Unified Design Guidelines allow for multiple methods for calculation of flow for a development. For this analysis, Method 1 — Fixture Count Determination was used. The building has a Peak Hourly Demand of 380 GPM. The total building square footage is 322,359 square feet (SF). The proposed building has 200,447 square feet (SF) of Type VA and 121,912 square feet (SF) of Type IA based on International Building Code. For worst case, Building Type VA was applied to the entire development of 322,359 square feet (SF). The International Fire Code Table B 105.1 lists this building to have a fire flow of 8,000 GPM. A 50% reduction as listed in the Unified Development Ordinance was applied to listed fire flow of 8,000 GPM, which requires the fire flow to be 4,000 GPM. This flow has been split between two fire hydrants on site as allowed in the Design Guidelines. A minimum flow of 1000 GPM was also applied to each of the four hydrants serving the site as an additional, supplemental scenario of analysis to provide the required 4000 GPM. Results Peak Demand Condition Peak demand conditions are considered to be municipal demand as determined from fixture counts. During peak conditions, system pressures throughout the development are greater than the required 35 psi. Resulting pressures range from 77 psi to 80 psi. WaterCAD results of the peak demand scenario are included as Appendix B of this memorandum. The Stack Water System Analysis April 24, 2012 Page 3 Fire Flow Conditions The fire flow demand of 4,000 gpm was added to peak flow and distributed evenly at the most hydraulically remote and highest elevation hydrant locations, represented by Junctions H-I and H-4. Results of the fire flow scenario show that residual pressures range from 61 psi to 66 psi, exceeding the minimum 20 psi requirement. Pipe velocities are all less than the maximum 12 fps. The WaterCAD results for the fire flow scenario are included in Appendix B. Results of the supplemental fire flow scenario show that residual pressures range from 62 psi to 66 psi, exceeding the minimum 20 psi requirement. Pipe velocities are all less than the maximum 12 fps. The WaterCAD results for the fire flow scenario are included in Appendix B. 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Test completed by Justin Tamplin, Paul Schoenfeld, Howard Mitchell, Wyatt J. Witness ICI'/�77�ai size rant number itot reading in PSI low in G.P.M. 711 University The Stack 2.5 A-080, A-081, A-082 and A-069 35, 40, 40 and 40 STATIC HYDRANT Location 801 University Hydrant number A-022 Static PSI 78 Residual PSI 60 Comments For Initial 'I I, Kmley-Horn L1 and Associates, Inc. Technical Memorandum To: City of College Station From: J. Chris Harris, P.E. Date: February 15, 2012 Subject: The Stack Fire Flow Conditions KHA Project No. 067543000 Purpose The proposed development consists of mixed use approximately 3.05 developed acres. This technical memorandum presents results of the water system analysis for the proposed development. This memorandum is divided into the following sections: • References and Design Criteria • Results • Conclusion References and Design Criteria References Water distribution mains throughout the development were sized by creating a hydraulic model of the system, using WaterCAD version 7.0 by Bentley Systems. The following data and references were used for creation of the model: Fire flow tests performed by College Station Utilities on December 28, 2011 near the proposed development site, attached as Appendix A. Design Criteria Water distribution mains were sized based on design criteria listed in the 2009 Bryan / College Station Unified Design Guidelines for Domestic Water. Design criteria used for this analysis includes: Suite 201 2800 South Texas Avenue Bryan, Texas 77802 The Stack Water System Analysis February 15, 2012 Page 2 Peak Flow Conditions o Provide minimum pressure of 35 pounds per square inch (psi) Fire Flow Conditions o Provide a fire flow of 2,500 gallons per minute (gpm) o Provide the required fire flow at the most hydraulically remote pairings of 2 adjacent fire hydrants in the system improvement in addition to the peak hourly flow. o A residual pressure of 20 psi is required o Velocity shall not exceed 12 feet per second (fps) The Unified Design Guidelines allow for multiple methods for calculation of flow for a development. For this analysis, Method 1 — Fixture Count Determination was used. The building has a Peak Hourly Demand of 380 gpm. The total building square footage is 322,359 square feet (SF). The proposed building has 200,447 square feet (SF) of Type VA and 121,912 square feet (SF) of Type IA based on International Building Code. For worst case, Building Type VA was applied to the entire development of 322,359 square feet (SF). The International Fire Code Table B 105.1 list this building to have a fie flow of 8,000 gpm. A 50% reduction as listed in the Unified Development Ordinance was applied to listed fire flow of 8,000 gpm which requires the fire flow to be 4,000 gpm. This flow has been split between two fire hydrants on site as allowed in the Design Guidelines. Results Peak Demand Condition Peak demand conditions are considered to be municipal demand as determined from fixture counts. During peak conditions, system pressures throughout the development are greater than the required 35 psi. Resulting pressures range from 77 psi to 80 psi. WaterCAD results of the peak demand scenario are included as Appendix B of this memorandum. The Stack Water System Analysis February 15, 2012 Page 3 Fire Flow Conditions The fire flow demand of 4,000 gpm was added to peak flow and distributed evenly at the most hydraulically remote and highest elevation hydrant locations, represented by Junctions H-1 and H-2. Results of the fire flow scenario show that residual pressures range from 60 psi to 63 psi, exceeding the minimum 20 psi requirement. Pipe velocities are all less than the maximum 12 fps. The WaterCAD results for the fire flow scenario are included in Appendix B. Conclusion In conclusion, the water distribution mains proposed for the development exceed the minimum requirements as described in this memorandum. Appendix A Fire Flow Test Results College Station Utilities t-e113ble, Afford;able, Community Ovined Date test completed Wednesday December 28, 2011 Time completed 1:45 P.M. Test completed by Justin Tamplin Witness Grant Faust Location Nozzle size Hydrant number Pitot reading in PSI Flow in G.P.M. Location Hydrant number Static PSI Residual PSI 311 College Ave. 2.5 A-021 62 301 College Ave. A-044 80 Comments This is the 8 inch line U College Station Utilities Reliable, Aifordable, Community Owned Date test completed Wednesday December 28, 2011 Time completed Test completed by Witness Justin Tamplin Grant Faust Comments This is the 12 inch line Appendix B Modeling Results Peak Hourly Demand FlexTable: Junction Table (TheStack.wtg) Current Time: 0.000 hours ID Label Elevation Zone Demand Demand (ft) Collection (gpm) <Collection:0 43 7-4 331.52 <None> 0 items> <Collection:0 49 3-6 331.85 <None> 0 items> <Collection: 1 64 THE STACK 337.00 <None> 380 items> Hydraulic Grade Pressure A (psi) 517.07 80.3 517.11 80.2 516.86 77.8 Bentley Systems, Inc. Haestad Methods Solution Bentley WaterCAD V81 (SELECTseries 1) TheStack.wtg Center [08.11,01,321 4/6/2012 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 FlexTable: Pipe Table (TheStack.wtg) Current Time: 0.000 hours ID Label Length (Scaled) Start Node Stop Node Diameter (ft) (in) 33 P-1 29.02 R-1 PMP-1 12.0 37 P-8 17.91 PMP-2 R-2 8.0 48 P-5 69.73 H-1 J-4 12.0 50 P-2 37.16 PMP-1 J-6 12.0 51 P-4 48.32 J-6 H-1 12.0 53 P-3 84.33 J-6 H-2 12.0 66 P-7 53.29 THE STACK PMP-2 8.0 67 P-6 73.56 THE STACK J-4 8.0 Material Hazen -Williams Has Check Minor Loss Flow Velocity C Valve? Coefficient (gpm) (ft/s) (Local) PVC 150.0 False 0,000 274 0.78 Ductile Iron 90.0 False 0.000 -106 0.68 PVC 150.0 False 0.000 274 0.78 PVC 150.0 False 0.000 274 0.78 PVC 150.0 False 0.000 274 0.78 PVC 150.0 False 0.000 0 0.00 Ductile Iron 130.0 False 0.000 -106 0.68 PVC 150.0 False 0.000 -274 1.75 Headless Has User Length (User Gradient Defined Length? Defined) (ft/ft) (ft) 0.000 True 20.00 0.001 True 20.00 0,000 True 136.56 0.000 True 10.00 0.000 True 77.03 0.000 True 333.92 0.000 True 235.73 0.001 True 163.07 Bentley Systems, Inc. Haestad Methods Solution Bentley WaterCAD V8i (SELECTseries 1) TheStack.wtg Center [08.11.01.32] 4/6/2012 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1.203-755-1666 Peak Hourly Demand and Fire Flow Demand FlexTable: Junction Table (TheStack.wtg) Current Time: 0.000 hours ID Label Elevation Zone Demand Demand (ft) Collection (gpm) 43 J-4 331.52 <None> <Collection:0 0 items> <Collection:0 49 J-6 331.85 <None> 0 items> 64 THE STACK 337.00 <None> <Collection: 1 380 items> Hydraulic Grade Pressure (ft) (psi) 479.20 63.9 478.97 63.7 482.14 62.8 Bentley Systems, Inc. Haestad Methods Solution Bentley WaterCAD Vei (SELECTsenes 1) TheStack.wtg Center [08A 1.01 .321 4/6/2012 27 Stemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 FlexTable: Hydrant Table (TheStack.wtg) Current Time: 0.000 hours ID Label Hydrant Status Include Lateral Emitter Lateral Length Loss? Coefficient (ft) (gpm/psi^n) 68 H-1 I Closed False 0.000 20.00 69 H-2 Closed False 0.000 20.00 Elevation Zone Demand Demand Hydraulic Grade Pressure (ft) Collection (gpm) (ft) (psi) 336.30 <None> 2,001 478.85 61.7 7<Co11j1,ec.1ion1 emsF337.79 ion:l <None> 2,000 476.62 60.1 ems> Bentley Systems, Inc. Haestad Methods Solution Bentley WaterCAD VBi (SELECTsenes 1) TheStack.wtg Center - [08.11.01.321 4/6/2012 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 FlexTable: Pipe Table (TheStack.wtg) Current Time: 0.000 hours ID Label Length Start Stop Node Diameter (Scaled) Node (in) (ft) Material 33 P-1 29.02 R-1 PMP-1 12.0 PVC 37 P-8 17.91 PMP-2 R-2 8.0 Ductile Iron 48 P-5 69.73 H-1 J-4 12.0 PVC 50 P-2 37.16 PMP-1 1-6 12.0 PVC 51 P-4 48.32 3-6 H-1 12.0 PVC 53 P-3 84,33 3-6 H-2 12.0 PVC 66 P-7 53.29 THE PMP-2 8.0 Ductile Iron TACK 67 P-6 73.56 THE J-4 8.0 PVC STACK Hazen -Williams Has Check Minor Loss Flow Velocity Headloss C Valve? Coefficient (gpm) (ft/s) Gradient (Local) (ft/ft) 150.0 False 0.000 2,854 8.10 0.014 90.0 False 0.000 -1,526 9.74 0.079 150.0 False 0.000 -1,146 3.25 0.003 150.0 False 0.000 2,854 8.10 0,014 150.0 False 0.000 854 2.42 0.001 150.0 False 0.000 2,000 5.67 0.007 130.0 False 0.000 -1,526 9.74 0,040 150.0 False 0.000 1,146 7.31 0.018 Has User Length (User Defined Length? Defined) (ft) True 20.00 True 20.00 True 136.56 True 10.00 True 77.03 True 333.92 True 235.73 True 163.07 Bentley Systems, Inc. Hassled Methods Solution Bentley WaterCAD Val (SELECTseries 1) TheStack.wtg Center [08.11,01,32] 4/6/2012 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666