1.
Choice of Pipe Material Influences
Drain Spacing and System Cost
Ehsan Ghane
Assistant Professor and Extension Specialist
@MSUEhsanGhane

2.
Effective Radius (Re) of a Drain Pipe
• Effective radius is the radius of an imaginary pipe with a completely
open wall
–Effective radius accounts for entrance head loss
• Dierickx (1999): Analytical Eq.
• Re is used
–DRAINMOD and RZWQM2
–Estimate drain spacing with Hooghoudt
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Ghane, MSU

3.
Rows of Perforations
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Ghane, MSU

4.
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Ghane, MSU
Sand-Slot Pipe
Regular-Perf Pipe

5.
Two Pipe Choices: Drain Sedimentation Issue
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6.
Pipe Manufacturers
• ADS (Michigan plant)
• Baughman Tile (Ohio)
• Fratco (Indiana)
• Haviland Drainage (Ohio)
• Prinsco (Minnesota)
• Springfield Plastics (Illinois)
• Timewell Drainage (Illinois)
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7.
Effective Radius (Re) of Pipe (Rows of Perforation)
• 4-inch, 4-row regular-perf pipe
–Re = 0.3 to 0.9 cm (average 0.6 cm)
• 4-inch, 8-row regular-perf pipe
–Re = 1.9 cm
• Most important: Rows
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Ghane, MSU

8.
Effective Radius (Re) of Pipe
• 4-inch, 4-row regular-perf pipe
–Re = 0.3 to 0.9 cm (average 0.6 cm)
• 4-inch, sock-wrapped pipe
–Re = 5.9 cm
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Ghane, MSU

9.
Sand-Tank Experiment
• 4-row sand-slot pipe, 8-row sand-slot pipe
• Regular-perf pipe wrapped with knitted-sock envelope

10.
Experiment Setup
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Ghane, MSU

11.
With Drain Sedimentation:
A Sock-Wrapped Pipe Has The Highest Drain Inflow
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Ghane, MSU
Drain inflow of a sock-wrapped
pipe is 29% higher than the 4-row
sand-slot pipe, when installed at
30-ft spacing and 2.5-ft depth

12.
A Sock-Wrapped Pipe Allows For a Wider Drain Spacing
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Ghane, MSU

13.
Which pipe properties increase water
entry into the pipe?

14.
Myth: Higher Water Inlet Area, Higher Drain Inflow
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Ghane, MSU

15.
Greater Subdivision of Openings Reduces Convergence
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Ghane, MSU

16.
Take-Home Messages
• Perforation shape and pattern affects Re
• Most Important: Number of perforation rows
–8-row is much better than 4-row, for same price
• Second most important: Slot length
–Longer, narrower slots are better than shorter, wider slots
• Slot width has minimal effect
• With drain sedimentation, sock-wrapped pipe is fastest
• Without drain sedimentation, 8-row reg-perf pipe is fastest
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Length
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17.
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3-Row Regular-Perf with Sock
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18.
Water Passed Through The Sock From All Directions
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