Xylem Wastewater (Technical Manual) - Manual (Page 5)

PAGE 5
Wastewater
Goulds Water Technology, Bell & Gossett,
Red Jacket Water Products, CentriPro
Storage of Water in Various Size Pipes
Pipe Size
Volume in
Pipe Size
Volume in
Gallons per Foot Gallons per Foot
1 1 ⁄
4
.06 6 1.4
1 1 ⁄
2
.09 8 2.6
2 .16 10 4.07
3 .36 12 5.87
4 .652
Minimum Flow to Maintain 2ft./sec. *Scouring Velocity in Various Pipes
Pipe Size Minimum GPM Pipe Size Minimum GPM
1 1 ⁄
4
9 6 180
1 1 ⁄
2
13 8 325
2 21 10 500
3 46 12 700
4 80
* Failure to maintain or exceed this velocity will result in clogged pipes.
Based on schedule 40 nominal pipe.
PIPE VOLUME AND VELOCITY
Example:
(A) 100 ft. of 2" plastic pipe with one (1) 90º elbow and one (1) swing check
valve.
90º elbow – equivalent to 5.5 ft. of straight pipe
Swing check – equivalent to 13.0 ft. of straight pipe
100 ft. of pipe – equivalent to 100 ft. of straight pipe
118.5 ft. = Total equivalent pipe
Figure friction loss for 118.5 ft. of pipe.
(B) Assume flow to be 80 GPM through 2" plastic pipe.
1. Friction loss table shows 11.43 ft. loss per 100 ft. of pipe.
2. In step (A) above we have determined total ft. of pipe to be 118.5 ft.
3. Convert 118.5 ft. to percentage 118.5 ÷ 100 = 1.185
4. Multiply 11.43
x 1.185
13.54455 or 13.5 ft. = Total friction loss in this system.
EQUIVALENT NUMBER OF FEET STRAIGHT PIPE FOR DIFFERENT FITTINGS
Size of fittings, Inches ½" ¾" 1" 1¼" 1½" 2" 2½" 3" 4" 5" 6" 8" 10"
90° Ell 1.5 2.0 2.7 3.5 4.3 5.5 6.5 8.0 10.0 14.0 15 20 25
45° Ell 0.8 1.0 1.3 1.7 2.0 2.5 3.0 3.8 5.0 6.3 7.1 9.4 12
Long Sweep Ell 1.0 1.4 1.7 2.3 2.7 3.5 4.2 5.2 7.0 9.0 11.0 14.0
Close Return Bend 3.6 5.0 6.0 8.3 10.0 13.0 15.0 18.0 24.0 31.0 37.0 39.0
Tee-Straight Run 1 2 2 3 3 4 5
Tee-Side Inlet or Outlet
3.3 4.5 5.7 7.6 9.0 12.0 14.0 17.0 22.0 27.0 31.0 40.0
or Pitless Adapter
Ball or Globe Valve Open
17.0 22.0 27.0 36.0 43.0 55.0 67.0 82.0 110.0 140.0 160.0 220.0
Angle Valve Open 8.4 12.0 15.0 18.0 22.0 28.0 33.0 42.0 58.0 70.0 83.0 110.0
Gate Valve-Fully Open 0.4 0.5 0.6 0.8 1.0 1.2 1.4 1.7 2.3 2.9 3.5 4.5
Check Valve (Swing) 4 5 7 9 11 13 16 20 26 33 39 52 65
In Line Check Valve
(Spring)
4 6 8 12 14 19 23 32 43 58
or Foot Valve
Friction Loss