1. Environmental Controls I/IG Lecture 7 Upfeed Systems Pipe Sizing Procedure Pipe Sizing Example Lecture 7 Upfeed Systems Pipe Sizing Procedure Pipe Sizing Example

2. Upfeed Systems

3. Pressure in Upfeed Systems Fixture pressure head Static head Friction head loss Meter pressure loss S: p. 913, F.21.13

4. Pressure in Upfeed Systems Proper fixture flow pressureA +Pressure lost due to heightB +Pressure lost due to frictionC +Pressure lost through meterD Total street main pressureE

5. A: Fixture Flow Pressure Pressure needed to get water through fixture S: p. 970, T.21.14

6. B: Pressure lost due to height Weight of water column S: p. 913, F.21.13

7. C: Pressure loss due to friction Initially unknown, must be calculated based on pressure remaining after accounting for the other factors

8. D: Pressure lost through meter Make initial size assumption and then repeat to optimum size S: p. 971, F.21.63a

9. E: Total Street Main Pressure Check with water company or fire department

10. Pipe Sizing Procedure

11. 1. Determine Supply Fixture Units Fixture units take into account usage diversity S: p. 974, T.21.15

12. 2. Calculate Demand Flow Use curve 1 for flush valve dominated system Use curve 2 for flush tank dominated systems S: p. 975, F.21.65a

13. 3. Determine the “Most Critical Fixture (MCF)” Highest and farthest from inlet main Confirm pressure required (A) Identify height (B) S: p. 958, F.21.52

14. 4. Determine Developed Length The total length of all horizontal and vertical pipes from the main to the MCF S: p. 995, F.22.17

15. 5. Determine Total Effective Length (TEL) Two approaches: 1. equivalent length or 2. multiply DL x 1.5 TEL= DL x 1.5 S: p. 976, T.21.16a

16. 6. Determine Street Main Pressure (E) Contact utility company or fire department

17. 7. Determine Pressure Available for Friction Loss Proper fixture flow pressureA +Pressure lost due to heightB +Pressure lost due to frictionC +Pressure lost through meterD Total street main pressureE or C=E-A-B-D

18. Meter Loss (D) Since D is unknown, pick an initial size, do calculation, repeat as needed to optimize flow C=E-A-B-D S: p. 971, F.21.63a

19. 8. Determine Friction loss/100’ C=E-A-B-D Δp/100’ = 100 x C/TEL

20. 9. Verify flow for meter size If flow > Total Demand (#2)  repeat 7-9 at smaller diameter If flow < Total Demand (#2)  repeat 7-9 at larger diameter S: p. 972, F.21.64a

21. 10. Select final meter size When flow > Total Demand (#2)  stop S: p. 972, F.21.64a

22. Pipe Sizing Example

23. Given Information Small Office Building  public numbers 2 Flush valve toilets 2 Lavatories 2 Drinking fountains 1 Service sink DL: 92’ MCF: Flush Valve Toilet, 16’ above water main Street Main Pressure: 44.1 psi

24. 1. Determine Supply Fixture Units Fixture units take into account usage diversity S: p. 974, T.21.15

25. 1. Determine Supply Fixture Units ColdHotTotal 2 Flush valve toilets20.00---20.0 2 Lavatories3.003.004.0 2 Drinking fountains0.50---0.5 1 Service sink2.252.253.0 25.755.2527.5

26. 2. Calculate Demand Flow 20 WSFU out of 27.5 WSFU are flush valves Use curve 1 for flush valve dominated system 40 gpm S: p. 975, F.21.65a

27. 3. Determine the Most Critical Fixture Confirm pressure required (A) 15 psi Height above main (B) 16’  7.0 psi S. p. 970, T.21.14

28. 4. Determine Developed Length Developed length 92’ S: p. 975, F.22.17 Note: this figure for generic reference only and does not illustrate the example problem

29. 5. Determine Total Effective Length (TEL) TEL= DL x 1.5 = 92 x 1.5 = 138’

30. 6. Determine Street Main Pressure (E) 44.1 psi

31. 7. Determine Pressure Available for Friction Loss Proper fixture flow pressureA15.0 +Pressure lost due to heightB7.0 +Pressure lost due to frictionC? +Pressure lost through meterD? Total street main pressureE44.1

32. Meter Loss (D) Pick an initial size 2” diameter… 1.4 psi S: p. 971, F.21.63a

33. 8. Determine Friction loss/100’ C=E-A-B-D = 44.1-15.0-7.0-1.4 = 20.7 psi Δp/100’=100 x 20.7/138 = 15 psi/100’

34. 9. Verify flow for meter size At 2” Flow=150 gpm > Total Demand 40 gpm At 1-1/2” Flow=60 gpm > Total Demand 40 gpm (Δp/100’= 13.1) At 1” Flow=13 gpm < Total Demand 40 gpm (Δp/100’= 5.1) S: p. 972 F.21.64a

35. 9. Verify flow for meter size When flow > Total Demand (#2)  stop At 1-1/2” Flow=60 gpm > Total Demand 40 gpm (Δp/100’= 13.1) S: p. 972 F.21.64a

36. Pipe Sizing Use Δp/100’= 13.1 psi/100’ Use fixture units to determine flow S: p. 972 F.21.64a

37. Pipe Sizing Use fixture units to determine flow Pay attention to flush valve domination S: p. 972 F.21.65a

38. Pipe Sizing Use Δp/100’= 13.1 psi/100’ Use fixture units to determine flow Select size which does not exceed 13.1 psi/100’ 20 gpm, use 1” 10 gpm, use ¾” Use runout sizes at each fixture S: p. 972, F.21.64a

39. Runout Pipe Sizing Use actual flow to size runouts Lavatory:2 gpm S: p.970, T.21.14

40. Runout Pipe Sizing Use Δp/100’= 13.1 psi/100’ Lavatory: 2 gpm S: p. 972, F.21.64a

41. Notation System Suggested for organizing data WSFUCurve Flow Diam. S: p. 995, F.22.17 3.6 2 4 ¾” 2.7 2 3 ½”