MATERIAL CHARACTERISTICS

BASIC CONSTRUCTION METHOD

SIZES AND DIMENSIONS

TYPICAL FLOATATION SCHEMATIC

BUOYANCY CAPACITIES FOR COMMON SIZE FLOATS

FLOATATION CALCULATIONS

 

MATERIAL CHARACTERISTICS

High Density Polyethylene pipe (HDPE) has been used since the early 1950's. Its life expectancy is approximately 50 years when transporting water at 73.4° F. HDPE is used for a variety of industrial applications such as corrosive gases, fuel gases, water, and sewage.

LIGHTWEIGHT – Polyethylene pipe is much lighter than concrete, cast iron, or steel pipe and it is easier to handle and install. The reduced manpower and equipment requirements of HDPE frequently results in significant installation savings.

THERMAL CHARACTERISTICS – Polyethylene is a thermoplastic material. The characteristics of polyethylene pipe are established at ambient temperature (23°C, 73.4°F). The pipe will expand and contract as it is heated or cooled.

TEMPERATURE RANGE – As the temperature decreases HDPE pipe gains strength. The pipe maintains its flexibility and integrity to -180° F.

ULTRAVIOLET PROTECTION – Black polyethylene pipe, containing 2 to 2.5% finely divided carbon black, can be safely stored outside in most climates for many years without damage from ultraviolet exposure. Carbon black is the most effective single additive to enhance the weathering characteristics of plastic material. Other UV stabilizers are not required when carbon black is used.

FUSION – During the heat fusion process, temperatures of 375° - 500° F are used. Butt fusion joints are visually inspected to ensure joint quality.

IMPACT OR HITTING – HDPE pipe is impact resistant. However, hitting the pipe with an instrument, such as a hammer, may result in uncontrolled rebound.

OTHER CHARACTERISTICS – Even when filled with water, HDPE pipe will float on the water surface. Seasonal freeze/thaw conditions have little effect on HDPE.

BACK TO TOP

 

BASIC CONSTRUCTION METHOD

Step 1 - Simply place a cross timber into the prescribed areas of the fused gussets, then bolt through. Half-inch galvanized bolts are typically used for all fastening. Cross timber sizes of 4" x 4", 4" x 6", or 4" x 8" can be used depending on the height desired.

Step 2 - Next place stringers using either 4" x 4", 4" x 6" or 4" x 8" timbers (again, depending on the desired height).

Note: Decking can be placed longitudinal on top of the cross-timbers if a low height is desired.

Connections - In order to connect several floats in progression, we suggest using heavier connecting timbers (such as 6" x 6"). When bolting through the connecting timbers we also recommend using heavier hardware (5/8" or 3/4" bolts). The size of the hardware and connecting timbers will depend on dock location and exposure.


Consultation with a marine contractor is advised.

BACK TO TOP

 

SIZES AND DIMENSIONS
Dimensions, In.
Nom. Size, In.
OD
T
DR
Weight - lbs/100 ft
14
14.000
0.538
26.0
996
14
14.000
0.431
32.5
805
16
16.000
0.615
26.0
1301
16
16.000
0.492
32.5
1050
18
18.000
0.554
32.5
1330
20
20.000
0.615
32.5
2034
22
22.000
0.677
32.5
1986
24
24.000
0.738
32.5
2362
26
26.000
0.800
32.5
2774
28
28.000
0.862
32.5
3219
30
30.000
0.923
32.5
3693
32
32.000
0.985
32.5
4204
OD = Pipe Outside Diameter (inches) • DR = OD /T • T = Minimum Wall Thickness

BACK TO TOP

 

TYPICAL FLOATATION SCHEMATIC

BACK TO TOP

BUOYANCY CAPACITIES FOR COMMON SIZE FLOATS
Float Size
Nominal O.D.Plastic Pontoon

Approximate Float Weight with decking/lbs

Carrying Capacity lbs
5'x20'
16"
1,300
1,900
6'x20'
16"
1,600
2,000
6'x20'
16"
2,300
2,900
5'x20'
18"
1,400
3,400
6'x20'
18"
1,800
3,100
6'x30'
18"
2,500
4,500

BACK TO TOP

 

FLOATATION CALCULATIONS

The REEL FLOATTM System is made of high density polyethylene pipe (HDPE). It typically has a density of 0.955 gm/cc. This means that the floatation device will float even when full of water (floats will not support extra weight when full of water).

REEL FLOATS are produced using a technique called heat fusion. This process provides a hermetically sealed float. Calculation of the supportable weight

Step 1 - Determine the weight to be supported. Determine the total weight to be supported and divide this value by the feet of float that you plan to use. This is the load per foot. When you have selected a size of float, add the float weight per foot to the load per foot. The float weight per foot values are found in Table 2.

Step 2 - Select a percentage of submergence. Select a percent of submergence for the float. The percent of submergence is the percent of the float diameter that is under water.

Step 3 - Determine support capacity Using the size of the float that you chose in Step 1, read the float buoyancy (B) from Table 2. This is the maximum amount of support that this float can provide. Using the percent of submergence, read the submergence factor (F) from Table 1. Multiply the float buoyancy (B) by the submergence factor (F). This will give the usable support per foot for the float.

Step 4 - Compare the usable support per foot to the load per foot. Compare the load per foot to the float support capacity per foot. If the load per foot is larger than the support capacity, a larger float will be needed. Select a larger float size and repeat steps 1 through 4. If the load per foot is less than the support capacity per foot, a smaller float may be usable.

Step 5 - Determine the actual submergence of the float. Once the proper size float has been determined, the actual submergence for the float may be determined by dividing the load per foot by the float buoyancy (B). This is the actual submergence factor (F). This actual percent submergence can be read from Table 1.

TABLE 1
Percent
Submergence
Submergence
Factor(F)
Percent
Submergence
Submergence
Factor(F)
Percent
Submergence
Submergence
Factor(F)
Percent
Submergence
Submergence
Factor(F)
5
0.019
30
0.252
55
0.564
80
0.858
10
0.052
35
0.312
60
0.623
85
0.906
15
0.094
40
0.377
65
0.688
90
0.948
20
0.142
45
0.436
70
0.748
95
0.981
25
0.196
50
0.500
75
0.804
100
1.000

 

TABLE 2
Nominal Size Inches
Actual Size Inches
Weight #/ft
Float Buoyancy (B) #/ft
Internal Volume Ft3 /ft
14
14.000
8.05
66.7
0.941
16
16.000
10.51
87.1
1.230
18
18.000
13.29
110
1.556
20
20.000
16.41
136
1.921
22
22.000
19.87
165
2.325
24
24.000
23.64
196
2.767
26
26.000
27.74
230
3.247
28
28.000
32.17
267
3.766
30
30.000
36.92
306
4.323
32
32.000
42.04
349
4.919
34
34.000
47.44
393
5.553
36
36.000
53.18
441
6.225

BACK TO TOP