ISCO Snap-Tite® Manual

Chapter 3 Cost Effectiveness Several studies have revealed that the largest expense on culvert projects is not the pipe itself, but the excavation, installation, inspection, maintenance, road repair, and liability. Because the Snap-Tite® Culvert Lining System is so easy to install, it reduces your overall culvert renewal costs. Snap-Tite® saves on labor costs by eliminating the time-consuming process of cutting and repairing roads. There is no need for specialized equipment, so you save money on costly rentals and labor. During down times from mowing or snow removal, existing highway crews can be productive by lining deteriorating culverts with Snap-Tite®.

Safety  Every year people who work on road crews are killed or injured by inattentive drivers. By using Snap-Tite® these workers can stay safely off the roadway to rehabilitate bad culverts.  There may be a road where there is too much traffic to close part or all of the roadway to dig and replace a deteriorated culvert. The answer is Snap-Tite®.  Some subdivisions and hospitals only have one road to enter and exit. If these roads have culverts, they are best rehabilitated with Snap-Tite®.

Cost Effectiveness

 When the existing culvert is six feet below the

road surface, it becomes a cost savings to install Snap-Tite® as compared to dig and replace. Then the deeper the culvert the more is saved by installing Snap-Tite® vs. dig and replace.  If the roadway has just been resurfaced and a culvert now needs to be replaced, use Snap-Tite® to reline the old culvert! No damage to the new road surface!  Some areas of the country have acidic soils and metal culverts only last a short time. Line the culverts with a high quality HDPE, Snap-Tite®.  You may have a concrete pipe that is in great shape but the joints are separating. Line the pipe with Snap-Tite® and grout the annular space. This will eliminate the pot holes from reappearing.  Pipe with a broken back got you down? If the angle is not more than 12 degrees, line it with Snap-Tite®.

1-800-233-1305 www.isco-pipe.com © Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

15

ISCO Snap-Tite® Manual

Cost Effectiveness

1-800-233-1305 www.isco-pipe.com 16

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual

Chapter 4 Improved Flow Characteristics Snap-Tite® liners have been developed to line aging and deteriorated culverts while increasing flow rates. This has been accomplished by the invention of the Snap-Tite® joint and the use of extruded high density polyethylene pipe. The Snap-Tite® joint allows sections of pipe to be joined together mechanically in the field without increasing the OD or decreasing the ID of the liner at the joint. This, plus the surface smoothness of the HDPE pipe, actually increases flow rate despite reducing the size of the culvert. Flow rate is measured by the Manning "N" factor. The corrugated inside surface of CMP creates turbulence in through-flow resulting in an "N" factor of .024. HDPE pipe, meanwhile, has a smooth surface and a much lower "N" factor of .00914 resulting in an increased flow rate despite a reduction in the size of the pipe. For instance, lining a 36" CMP with a 30" Snap-Tite® liner will increase the flow rate by 20%.

Flow Characteristics

Factors Influencing Flow The volume of water that can flow through a pipe changes with the slope of the pipe, the level of the water in the pipe and the physical size of the pipe. The slope of the pipe indicates the amount of change in elevation in the pipe. A pipe that is on a “flat” slope carries less water than a pipe that changes greatly. The level of water in the pipe changes the flow. One normally thinks that a pipe that is 100% full will carry more water than one that is 95% full. Table 2 below shows that when a pipe is 95% full, it actually carries more flow than at 100%.

Table 2: Flow Capacity % Capacity 10 20 30 40 50 60 70 80 90 95 100

Velocity (compared to % full) 36 56 72 88 100 108 114 116 115 111 100

Flow (compared to % full) 3 9 19 33 50 67 84 98 107 106 100

When a pipe is partially full, the liquid in the pipe has less contact with the pipe wall than when it is full. This results in less friction and more flow. The Manning equation is used to calculate flow in all types of piping. The formula is: V= (1.486/n) / R.66 * S.5

1-800-233-1305 www.isco-pipe.com

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

17

ISCO Snap-Tite® Manual V= Velocity in feet/second, f/s n= Manning number = .00914 for Snap-Tite® R= hydraulic radius in feet S= Hydraulic gradient (feet/foot) The amount of liquid flow in a pipe can be determined by combining the Manning formula with; Q= AV Where Q= volume of flow (Volume in cubic feet per second) A= cross-section flow area in feet or inches V= Velocity from Manning formula, flow in cubic feet / second The above equation when combined with the Manning equation and term defined can be restated as: R= Df/4 for feet or di/48 for inches Df = pipe interior diameter in feet Di = pipe diameter in inches Q = .0006136 * (Df 2.687 * S.5/n) = flow in cubic feet/second Qi = 0.275 * (Di 2.667 * S.5/n) = flow in gallons per minute Design Considerations When Lining Existing Culverts

Flow Characteristics

Many existing culverts were properly designed for 100 year flood conditions. These culverts rarely have water over the top of the inlet. When existing culverts are properly designed, then flow after lining will not change as long as the capacity of the lined culvert is equal to the old culvert. When lining culverts, both inlet and outlet control must be considered. The flow through a culvert, with or without a liner, is dependent on the inlet geometry and headwater depth. Inlet control means that flow through the culvert is restricted by culvert entrance characteristics. Short, smooth, or greatly sloping culverts usually have inlet control. When water is over the inlet, the area of the pipe opening will control flow. The Manning formula does not apply. If the original culvert had marginal flow, then the liner will restrict flow when water is above the inlet. Often a lined pipe will increase flow as long as the water level behind the culvert is below the top of the lined culvert, but because the size of the opening has decreased, flow will decrease when water is above the top of the culvert. Then as the height of water above the inlet increases, flow will increase. Outlet control occurs when flow through the culvert is limited by friction between the water flowing and the culvert surface. Friction is usually given as the Manning “n” factor. Long, rough, or slightly sloping culverts are subject to outlet control. The name “outlet control” is confusing. Friction along the total length of the culvert is as important as the outlet conditions. The main concern at discharge is the depth and shape of the outlet. The comparative flow information provided in this Design Guide is based on flow through a partially full to full pipe. The Manning formula is used to estimate flow. A lined culvert that has a good inlet geometry (usually a wing wall directing flow) will often improve flow through the culvert as long as water is below the top of the culvert or liner.

1-800-233-1305 www.isco-pipe.com 18

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual

Snap-Tite® Liner in place

Flow Characteristics

Concrete pipe joint separation causes infiltration, road surface degradation

1-800-233-1305 www.isco-pipe.com

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

19

ISCO Snap-Tite® Manual

Snap-Tite® liner in rusted CMP culvert

Flow Characteristics High flow discharge from lined culvert

Snap-Tite® liner in Box Culvert

1-800-233-1305 www.isco-pipe.com 20

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual

Table 3: Snap-Tite® liner Provides greater flow than CMP

CMP ID

Snap-Tite® Liner Size (in.) OD

CMP Flow (gpm)

Snap-Tite® (gpm)

% of Flow

12" 15" 18" 18" 21" 21" 24" 24" 24" 27" 27" 30" 30" 36" 36" 36" 42" 42" 48" 48" 54" 54" 60" 60" 66" 66" 72" 84"

10.75 12.75 14 16 16 18 18 20 22 22 24 24 28 28 30 32 32 36 36 42 42 48 48 54 54 63 63 63

274.00 496.00 807.00 807.00 1,218.00 1,218.00 1,738.00 1,738.00 1,738.00 2,380.00 2,380.00 3,152.00 3,152.00 5,126.00 5,126.00 5,126.00 7,733.00 7,733.00 11,041.00 11,041.00 15,115.00 15,115.00 20,019.00 20,019.00 25,813.00 25,813.00 32,556.00 49,111.00

448.00 706.00 906.00 1,293.00 1,293.00 1,770.00 1,770.00 2,345.00 3,023.00 3,023.00 3,813.00 3,813.00 5,752.00 5,752.00 6,914.00 8,213.00 8,213.00 11,244.00 11,244.00 16,961.00 16,961.00 24,217.00 24,217.00 33,155.00 33,155.00 50,015.00 50,015.00 50,015.00

164% 142% 112% 160% 106% 145% 102% 135% 174% 127% 160% 121% 182% 112% 135% 160% 106% 145% 102% 154% 112% 160% 121% 166% 128% 194% 154% 102%

Flow Characteristics

Snap-Tite® Liner: n = 0.00914 Corrugated Metal Pipe: n = 0.024

1-800-233-1305 www.isco-pipe.com © Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

21

ISCO Snap-Tite® Manual

Table 4: Flow Comparison between Snap-Tite® and RCP Culverts

Flow Characteristics

RCP Size Concrete ID

Snap-Tite® Size (in.) OD

RCP Flow (gpm)

Snap-Tite® (gpm)

% of Flow

12" 15" 18" 18" 21" 21" 24" 24" 24" 27" 27" 30" 30" 36" 36" 36" 42" 42" 48" 48" 54" 54" 60" 60" 66" 66" 72" 84"

10.75 12.75 14 16 16 18 18 20 22 22 24 24 28 28 30 32 32 36 36 42 42 48 48 54 54 63 63 63

438.00 794.00 1,292.00 1,292.00 1,948.00 1,948.00 2,781.00 2,781.00 2,781.00 3,808.00 3,808.00 5,043.00 5,043.00 8,202.00 8,202.00 8,202.00 12,372.00 12,372.00 17,665.00 17,665.00 24,182.00 24,182.00 32,031.00 32,031.00 41,301.00 41,301.00 52,089.00 78,577.00

448.00 706.00 906.00 1,293.00 1,293.00 1,770.00 1,770.00 2,345.00 3,023.00 3,023.00 3,813.00 3,813.00 5,752.00 5,752.00 6,914.00 8,213.00 8,213.00 11,244.00 11,244.00 16,961.00 16,961.00 24,217.00 24,217.00 33,155.00 33,155.00 50,015.00 50,015.00 50,015.00

102% 89% 70% 100% 66% 91% 64% 84% 109% 79% 100% 76% 114% 70% 84% 100% 66% 91% 64% 96% 70% 100% 76% 104% 80% 121% 96% 64%

Snap-Tite® Liner: n = 0.00914 Concrete Pipe: n = 0.012 or 0.013

1-800-233-1305 www.isco-pipe.com 22

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual

Table: 5 Comparative Flow for Concrete Box Culvert with Snap-Tite® Liner Existing Concrete Box Size ID (In.) 3 ft. x 3 ft. 3 ft. x 3 ft. 4 ft. x 4 ft. 4 ft. x 4 ft. 5 ft. x 5 ft. 5 ft. x 5 ft. 6 ft. x 6 ft. 6 ft. x 6 ft.

Manning n factor *

Snap-Tite® Liner Size

Box Full Flow cu ft/sec

SnapTite®Flow cu ft/sec

0.012 0.013 0.012 0.013 0.012 0.013 0.012 0.013

36” 36” 48” 48” 54” 54” 63” 63”

29 27 60 50 120 98 190 170

25 25 54 54 74 74 112 112

% of Flow 86 93 90 108 62 76 59 66

Snap-Tite® Liner: n = 0.00914 Concrete Pipe: n = 0.012 or 0.013

Table 6: Oval Concrete Culverts Oval Concrete Culverts

Equivalent Circular Concrete

Flow in cubic ft per second for Concrete Oval Culvert

14" x 23" 19" x 30" 24" x 36" 29" x 45" 34" x 53" 38" x 60" 43" x 60" 48" x 76" 63" x 83" 63" x 83" 58" x 91"

16" 24" 30" 36" 42" 48" 54" 60" 66" 66" 72"

2.88 6.21 11.26 18.31 27.62 39.43 53.98 71.50 92.19 92.19 116.27

Equivalent Snap-Tite®

Flow fps

% Flow

16" 22" 28" 32" 36" 42" 48" 54" 54" 63" 63"

2.89 6.76 12.87 18.37 25.15 37.94 54.17 74.17 74.17 111.88 111.88

100 109 114 100 91 96 100 104 80 121 96

Flow Characteristics

Snap-Tite® Liner: n = 0.00914 Concrete Pipe: n = 0.012 or 0.013 Note: Snap-Tite® is available as an oval liner. For additional information talk to a Snap-Tite® Sales Representative. Drawing 5: Oval Concrete Pipe

1-800-233-1305 www.isco-pipe.com © Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

23

ISCO Snap-Tite® Manual Utah State University Utah Water Research Laboratory College of Engineering 8200 Old Main Hill Logan, UT 84322-8200 Bruce Larson ISCO Industries, LLC 926 Baxter Avenue Louisville, KY 40204 April 9, 2004 Reference: Certification of Manning “n” Value for Snap-Tite HDPE Pipe Dear Mr. Larson:

Flow Characteristics

To determine the hydraulic roughness characteristics of Snap-Tite Culvert Liner made by ISCO Industries, LLC 220 feet of 24” OD (average I.D. = 22.29”) was flow tested at the Utah Water Research Laboratory (UWRL) located in Logan, Utah. The 24-inch Snap-Tite pipe was installed in the laboratory 48-inch test line. Twelve sections of Snap-Tite Liner pipe were provided (eleven 20 ft. lengths and one 11.5 ft. length). When assembled, the total length of the test pipe was 220 feet. The pipe came with Snap-Tite joints. No leaks were observed during testing. The pressure taps were used to monitor the change in piezometric head (head loss) across the length of the test pipe. The piezometric head represents the sum of the pressure and elevation head. Flow rates were determined using 20- and 48-inch ASME flow tubes. The flow meters are calibrated regularly using the weight and volumetric tanks at Utah Water Research Laboratory and are traceable by weight by the National Institute of Standards and Technology. Differential pressure manometers were also used with the flow tube meters for determining flow rates. All flow testing was performed with a pressured pipe. The pipe was tested over the design velocity range recommended by the National Corrugated Steel Pipe Associations’s CPS Durability Guide for a “Level 3” product (5-15 fps). The average Manning’s value for Reynolds numbers greater than 1,000,000 was 0.00914. Sincerely, Blake P. Tullis, Ph.D

1-800-233-1305 www.isco-pipe.com 24

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual

Chapter 5 Product Dimensions Large Diameter Culvert Liner Liners for large culverts are provided in two products. Snap-Tite® culvert liners are made from solid wall HDPE pipe. This product is joined using the patented Snap-Tite® mechanical joint. It is easy to install, reliable, and has a water tight seal. The dimensions for Snap-Tite® Culvert liners are provided on page 26, in Table 7, " Snap-Tite® Dimensions and weights for DR 32.5".

Profile wall pipe that can be used for culvert lining. Profile wall HDPE pipe has smooth interior and exterior with a hollow core. The geometry of this product makes it very stiff. It is joined by extrusion welding. See Table 8: Profile Wall Pipe Dimensions, Page 27 for dimensions.

Product Dimensions

1-800-233-1305 www.isco-pipe.com © Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

25

ISCO Snap-Tite® Manual

Table 7: Snap-Tite® Dimensions and Weights for DR 32.5 Liner

Culvert Size ID 12" ID 15" ID 18" ID 18" ID 21" ID 21" ID 24" ID 24" ID 27" ID 27" ID 30" ID 30" ID 36" ID 36" ID 36" ID 42" ID 42" ID 48" ID 48" ID 54" ID 54" ID 60" ID 60" ID 72" ID 72" ID 84" ID

Product Dimensions

Liner Size OD 10.75" 12.75" 14" 16" 16" 18" 20" 22" 22" 24" 24" 28" 28" 30" 32" 34" 36" 39.37" 42" 42" 48" 48" 54" 54" 63" 63"

Weight/ft 4.75 6.67 8.05 10.50 10.50 13.30 16.42 19.86 19.86 23.62 23.62 32.19 32.19 36.93 42.04 47.43 53.20 63.69 72.37 72.37 94.55 94.55 119.70 119.70 162.98 162.98

Notes 1.

Snap-Tite® sizes 8" thru 18", standard lay lengths are 11', 21', and 26'.

2.

Snap-Tite® sizes 20" thru 63", standard lay lengths are 9', 19', and 24'.

3.

Special lengths are available in all sizes.

1-800-233-1305 www.isco-pipe.com 26

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual

Table 8: Profile Wall Pipe Dimensions Profile Wall Pipe is manufactured in accordance with ASTM F894. Profile Wall Pipe Size

Nominal Pipe ID (inches)

18 19.5 21 24 27 30 33 36 40 42 48 54 60 66 72 78 84 90 96 108 120

18 19.5 21 24 27 30 33 36 40 42 48 54 60 66 72 78 84 90 96 108 120

Average Outside Diameter for Max. Stiffness (inches)

for Min. Stiffness (inches)

20.2 21.7 23.7 27.1 30.4 33.8 39.6 40.7 45.2 47.5 53.8 60.5 67.2 73.9 80.6 87.4 94.1 100.8 107.5 121.0 134.4

19.9 21.7 22.9 26.2 30.0 32.7 37.6 39.1 43.4 45.4 51.8 58.7 65.2 70.7 77.8 84.5 90.5 97.2 103.2 115.9 128.6

Notes 1. 2. 3. 4.

The above chart represents a range of sizes and stiffness classes. Stock will vary from plant to plant. All dimensions approximate. Contact ISCO for exact size and availability. Profile Wall Pipe is available in a series of different Ring Stiffness Constants (RSC) values that comply with ASTM F-894-98 “Polyethylene Large Diameter Profile Wall Sewer and Drain Pipe”. Profile Wall Pipe is available in standard lengths of 20 and 40 feet with custom sizes 3 feet to 50 feet. Contact your local ISCO Representative for design assistance to meet your specific project needs.

1-800-233-1305 www.isco-pipe.com © Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

27

ISCO Snap-Tite® Manual

Chapter 6 Design Guidelines

Design Guidelines

Drawing: 6 Snap-Tite® Male End and Joined to Female End 1.0 Introduction Due to the high cost associated with excavation, restoration, and traffic re-routing, it is frequently cost effective to restore existing culverts rather than replace. The main advantages of rehabilitation over restoration include: • Traffic disruption is minimized or even completely eliminated. • Contamination of watercourses is avoided. • Existing slope and vegetation need not be disturbed therefore there is little need for concern regarding slope stability and/or erosion. The cost of restoring trees, fences, embankments, guard rails and reinstating vegetation is avoided.

• Existing pavement is undisturbed therefore there is no concern regarding pavement settlement or jointing. • Due to the very smooth inside surface of the liner pipe the flow capacity of the restored culvert may frequently exceed that of the original culvert even when in new condition. 2.0 Select a Liner Pipe Diameter To maximize flow capacity the largest feasible diameter of liner pipe should be selected. This is limited by the size and condition of the existing culvert, through which it will be inserted. Sufficient clearance will be required to ensure trouble-free insertion. Consider the length of pull, severity of any off-set joints, localized deflected areas, and structural integrity of the existing culvert.

1-800-233-1305 www.isco-pipe.com 28

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

ISCO Snap-Tite® Manual The selection of a polyethylene liner that has an outside diameter 10% less than the inside diameter of the existing culvert will generally serve two purposes. First, this size differential usually provides adequate clearance to accommodate the insertion process. And second, 90–100% or more of the original flow capacity may be maintained. A differential of less than 10% may provide adequate clearance in larger diameter culverts. It is quite common to select a 5–10% differential for culverts with a diameter greater than 24 inches, assuming that the condition of the existing culvert will permit its insertion. Field inspection of the existing culvert is vital to ensure a proper liner selection and installation. 3.0 Determine the Structural Requirements for the Liner Pipe The polyethylene liner pipe may be required to withstand the following loading conditions: • Insertion, i.e. push/pull forces • Grouting pressures • Ground water pressure

Fortunately, high density polyethylene (HDPE) is very tolerant of deformation, scratches, scrapes and gouges. For the purposes of a culvert liner it is quite safe to assume that if the liner has been installed without obvious damage, i.e. tears through the wall, kinks or cracks, the liner will function adequately. 3.1 Insertion Forces It is extremely difficult to estimate the amount of force required to push or pull a polyethylene liner pipe into an existing CMP culvert. These forces can, however, be minimized by properly inspecting and cleaning the existing culvert to ensure that all sharp edges are repaired and that all debris has been removed. Flowing water within the culvert during installation will actually aid the installation process rather than hamper it. 3.2 Grouting Pressures Prior to its initial set-up, grout will act as a fluid and apply an external hydrostatic pressure to the liner. Care must be taken to ensure that any unbalanced grouting pressures do not exceed the safe allowable limits for the HDPE liner. Unbalanced grouting pressures can be minimized by utilizing low density grout and/or by installing the grout in lifts. Table 9 provides allowable grout pressure for Snap-Tite® Culvert Liner.

Design Guidelines

• Earth pressures • Traffic loads

Table 9: Maximum Grouting Pressure (Ring Compression Strength) for Solid Wall Snap-Tite® Culvert Liner Service Life

DR 32.5

DR 26

10 hours Long term

2.2 psi 1.1 psi

4.4 psi 2.2 psi

Notes: Values based on 1% deflection in liner. Increased deflection decreases strength. This table based on 73 degrees F. As temperature increases, strength decreases. A decrease in temperature increases strength. One psi equal 2.31 feet of water.

1-800-233-1305 www.isco-pipe.com

© Copyright 2006 ISCO Industries, LLC. All Rights Reserved.

29