| Improve Sewer
Hydraulics With HOBAS Sliplining |
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Introduction
Hydraulics is typically an important consideration when
planning pipeline rehabilitation. When sliplining is the
chosen method, a slight diameter decrease will result.
However, because of the much better flow characteristics of
HOBAS liner pipe, normally the rehabilitated line's
hydraulics are improved relative to its existing condition.
Parameters
The parameters that effect the changed hydraulics are the
host and liner pipes' Manning's "n", diameter, and
slope. Since the slope is unchanged, the relative flow
capacity is computed as follows:
(QHOBAS / QExisting) = (nExisting
/ nHOBAS) (DHOBAS / DExisting)(8
/ 3)
Characteristics
The n value of existing sewers varies widely, perhaps from
0.013 to 0.024 or higher. Due to corrosion, off-set joints,
sliming, and other deterioration, a likely value for aged
sewers is at least 0.018. The n value for new HOBAS pipes
has been measured at 0.009. After several years of service
(sliming, etc.), one agency determined an n value of 0.011.
Chart
The chart below shows the ratios of flow capacity of the
HOBAS liner (Q HOBAS) to the host pipe (Q Existing) for
various diameter combinations and ranges of Manning's
"n". A ratio of greater than one indicates
improved flow capacity after lining with HOBAS, while a
value below one means a reduced flow capacity after the
rehabilitation. A 1.1 ratio is a 10% flow capacity increase.
A 0.9 ratio is a 10% flow capacity decrease. |
| Host
Pipe Existing Flow Coefficient, n |
|
| |
|
0.013 |
0.014 |
0.015 |
0.016 |
0.017 |
0.018 |
0.019 |
0.020 |
0.021 |
0.022 |
0.023 |
0.024 |
|
| 20"
into 24" |
0.009 |
0.961 |
1.035 |
1.109 |
1.183 |
1.257 |
1.331 |
1.405 |
1.479 |
1.553 |
1.627 |
1.700 |
1.774 |
20"
into 24" |
| 0.010 |
0.865 |
0.932 |
0.998 |
1.065 |
1.131 |
1.198 |
1.264 |
1.331 |
1.397 |
1.464 |
1.530 |
1.597 |
| 0.011 |
0.786 |
0.847 |
0.907 |
0.968 |
1.028 |
1.089 |
1.149 |
1.210 |
1.270 |
1.331 |
1.391 |
1.452 |
| 24"
into 30" |
0.009 |
0.851 |
0.916 |
0.982 |
1.047 |
1.113 |
1.178 |
1.244 |
1.309 |
1.375 |
1.440 |
1.505 |
1.571 |
24"
into 30" |
| 0.010 |
0.766 |
0.825 |
0.884 |
0.943 |
1.001 |
1.060 |
1.119 |
1.178 |
1.237 |
1.296 |
1.355 |
1.414 |
| 0.011 |
0.696 |
0.750 |
0.803 |
0.857 |
0.910 |
0.964 |
1.017 |
1.071 |
1.125 |
1.178 |
1.232 |
1.285 |
| 30"
into 36" |
0.009 |
0.936 |
1008 |
1.081 |
1.153 |
1.225 |
1.297 |
1.369 |
1.441 |
1.513 |
1.585 |
1.657 |
1.729 |
30"
into 36" |
| 0.010 |
0.843 |
0.908 |
0.972 |
1.037 |
1.102 |
1.167 |
1.232 |
1.297 |
1.361 |
1.426 |
1.491 |
1.556 |
| 0.011 |
0.766 |
0.825 |
0.884 |
0.943 |
1.002 |
1.061 |
1.120 |
1.179 |
1.238 |
1.297 |
1.356 |
1.414 |
| 36"
into 42" |
0.009 |
1.001 |
1.078 |
1.155 |
1.232 |
1.309 |
1.386 |
1.463 |
1.540 |
1.617 |
1.694 |
1.771 |
1.848 |
36"
into 42" |
| 0.010 |
0.901 |
0.970 |
1.039 |
1.109 |
1.178 |
1.247 |
1.316 |
1.386 |
1.455 |
1.524 |
1.593 |
1.663 |
| 0.011 |
0.819 |
0.882 |
0.945 |
1.008 |
1.071 |
1.134 |
1.197 |
1.260 |
1.323 |
1.386 |
1.449 |
1.512 |
| 42"
into 48" |
0.009 |
1.051 |
1.132 |
1.212 |
1.293 |
1.374 |
1.455 |
1.536 |
1.616 |
1.697 |
1.778 |
1.859 |
1.940 |
42"
into 48" |
| 0.010 |
0.946 |
1.018 |
1.091 |
1.164 |
1.237 |
1.309 |
1.382 |
1.455 |
1.528 |
1.600 |
1.673 |
1.746 |
| 0.011 |
0.860 |
0.926 |
0.992 |
1.058 |
1.124 |
1.190 |
1.256 |
1.323 |
1.389 |
1.455 |
1.521 |
1.587 |
| 48"
into 54" |
0.009 |
1.097 |
1.181 |
1.265 |
1.350 |
1.434 |
1.518 |
1.603 |
1.687 |
1.771 |
1.856 |
1.940 |
2.025 |
48"
into 54" |
| 0.010 |
0.987 |
1.063 |
1.139 |
1.215 |
1.291 |
1.367 |
1.442 |
1.518 |
1.594 |
1.670 |
1.746 |
1.822 |
| 0.011 |
0.897 |
0.966 |
1.035 |
1.104 |
1.173 |
1.242 |
1.311 |
1.380 |
1.449 |
1.518 |
1.587 |
1.656 |
| 54"
into 60" |
0.009 |
1.129 |
1.216 |
1.302 |
1.389 |
1.476 |
1.563 |
1.650 |
1.737 |
1.823 |
1.910 |
1.997 |
2.084 |
54"
into 60" |
| 0.010 |
1.016 |
1.094 |
1.172 |
1.250 |
1.328 |
1.407 |
1.485 |
1.563 |
1.641 |
1.719 |
1.797 |
1.875 |
| 0.011 |
0.924 |
0.995 |
1.066 |
1.137 |
1.208 |
1.279 |
1.350 |
1.421 |
1.492 |
1.563 |
1.634 |
1.705 |
| 60"
into 66" |
0.009 |
1.135 |
1.223 |
1.310 |
1.397 |
1.485 |
1.572 |
1.659 |
1.747 |
1.834 |
1.921 |
2.009 |
2.096 |
60"
into 66" |
| 0.010 |
1.022 |
1.100 |
1.179 |
1.258 |
1.336 |
1.415 |
1.493 |
1.572 |
1.650 |
1.729 |
1.808 |
1.886 |
| 0.011 |
0.929 |
1.000 |
1.072 |
1.143 |
1.215 |
1.286 |
1.358 |
1.429 |
1.500 |
1.572 |
1.643 |
1.715 |
| 66"
into 72" |
0.009 |
1.164 |
1.253 |
1.343 |
1.433 |
1.522 |
1.612 |
1.701 |
1.791 |
1.880 |
1.970 |
2.059 |
2.149 |
66"
into 72" |
| 0.010 |
1.048 |
1.128 |
1.209 |
1.289 |
1.370 |
1.450 |
1.531 |
1.612 |
1.692 |
1.773 |
1.853 |
1.934 |
| 0.011 |
0.952 |
1.026 |
1.099 |
1.172 |
1.245 |
1.319 |
1.392 |
1.465 |
1.538 |
1.612 |
1.685 |
1.758 |
| 72"
into 78" |
0.009 |
1.184 |
1.275 |
1.366 |
1.457 |
1.549 |
1.640 |
1.731 |
1.822 |
1.913 |
2.004 |
2.095 |
2.186 |
72"
into 78" |
| 0.010 |
1.066 |
1.148 |
1.230 |
1.312 |
1.394 |
1.476 |
1.558 |
1.640 |
1.722 |
1.804 |
1.886 |
1.968 |
| 0.011 |
0.969 |
1.043 |
1.118 |
1.192 |
1.267 |
1.342 |
1.416 |
1.491 |
1.565 |
1.640 |
1.714 |
1.789 |
| 72"
into 84" |
0.009 |
0.972 |
1.047 |
1.121 |
1.196 |
1.271 |
1.346 |
1.420 |
1.495 |
1.570 |
1.645 |
1.719 |
1.794 |
72"
into 84" |
| 0.010 |
0.875 |
0.942 |
1.009 |
1.076 |
1.144 |
1.211 |
1.278 |
1.346 |
1.413 |
1.480 |
1.547 |
1.615 |
| 0.011 |
0.795 |
0.856 |
0.917 |
0.979 |
1.040 |
1.101 |
1.162 |
1.223 |
1.284 |
1.346 |
1.407 |
1.468 |
| 84"FL
into 90" |
0.009 |
1.183 |
1.274 |
1.365 |
1.456 |
1.547 |
1.638 |
1.729 |
1.820 |
1.911 |
2.002 |
2.093 |
2.183 |
84"FL
into 90" |
| 0.010 |
1.064 |
1.146 |
1.228 |
1.310 |
1.392 |
1.474 |
1.556 |
1.638 |
1.720 |
1.801 |
1.883 |
1.965 |
| 0.011 |
0.968 |
1.042 |
1.117 |
1.191 |
1.265 |
1.340 |
1.414 |
1.489 |
1.563 |
1.638 |
1.712 |
1.768 |
| 84"
into 96" |
0.009 |
0.996 |
1.072 |
1.149 |
1.226 |
1.302 |
1.379 |
1.455 |
1.532 |
1.608 |
1.685 |
1.762 |
1.838 |
84"
into 96" |
| 0.010 |
0.896 |
0.965 |
1.034 |
1.103 |
1.172 |
1.241 |
1.310 |
1.379 |
1.448 |
1.517 |
1.586 |
1.654 |
| 0.011 |
0.815 |
0.877 |
0.940 |
1.003 |
1.065 |
1.128 |
1.191 |
1.253 |
1.316 |
1.379 |
1.441 |
1.504 |
| 96"
into 102" |
0.009 |
1.215 |
1.309 |
1.402 |
1.496 |
1.589 |
1.683 |
1.776 |
1.870 |
1.963 |
2.057 |
2.150 |
2.243 |
96"
into 102" |
| 0.010 |
1.094 |
1.178 |
1.262 |
1.346 |
1.430 |
1514 |
1.598 |
1.683 |
1.767 |
1.851 |
1.935 |
2.019 |
| 0.011 |
0.994 |
1.071 |
1.147 |
1.224 |
1.300 |
1.377 |
1.453 |
1.530 |
1.606 |
1.683 |
1.759 |
1.836 |
| 96"
into 108" |
0.009 |
1.043 |
1.124 |
1.204 |
1.284 |
1.364 |
1.445 |
1.525 |
1.605 |
1.686 |
1.766 |
1.846 |
1.926 |
96"
into 108" |
| 0.010 |
0.939 |
1.011 |
1.084 |
1.156 |
1.228 |
1.300 |
1.372 |
1.445 |
1.517 |
1.589 |
1.661 |
1.734 |
| 0.011 |
0.854 |
0.919 |
0.985 |
1.051 |
1.116 |
1.182 |
1.248 |
1.313 |
1.379 |
1.445 |
1.510 |
1.576 |
|
- HOBAS Diameters are
nominal for 36 psi pipe stiffness
- Existing Sewer assumed
full sized, Nominal diameter = ID
- FL = Flush Joint. In tight
fit cases, it may be required to utilize a flush joint.
The ID's of the flush joint are nominal for the typical
minimum flush joint pipes.
- HOBAS 84" nominal
size is based on the 87.0 OD mold.
Benefits
Sliplining rehabilitation of sewers with HOBAS pipes
provides many benefits. Not only is the flow capacity
frequently increased, but the host pipe is structurally
reinforced, corrosion is stopped, and leakage is eliminated.
Conclusion
To enjoy the many benefits of sliplining rehabilitation,
specify and use HOBAS pipes on your next project. |
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| SHOW |
DATE |
BOOTH |
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Apr 27- May 2 |
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