NJ Trenchless Sewer Pipe Repairs
Call us any time for fast, reliable trenchless sewer repair and other NJ sewer services!
Sewer excavation can be a major hassle. No one wants to have their lawn and yard torn up or their driveway demolished because a failed sewer line needs to be replaced or repaired. The problems with open cut trenching are compounded for municipal sewer repair, when disruption to traffic and nearby businesses is a serious concern for communities.
At A1 Sewer & Drain Services, we provide a solution in the form of trenchless sewer repair. We’re the region’s leading providers of NJ sewer services, including trenchless solutions for installing, fixing, and replacing underground water, sewer, and natural gas pipes. We’re always available for fast, responsive same-day service, including 24-hour emergency sewer repairs. Call us any time for service today, at 201-645-0888.
Slip Lining for Trenchless Sewer Repairs in NJ
Sliplining, first used in the 1940s, was one of the first trenchless solutions to be developed for rehabilitating underground sewer and water lines. Like cure-in-place pipe (CIPP) sewer relining, which was a later innovation, sliplining uses a “pipe within a pipe” approach to resolve problems like cracks and leaks in pipes that otherwise retain their overall structural stability.
For sliplining, a new pipe with a slightly smaller diameter is pulled through the old pipe. Grout is used to fill up the annular space between the old pipe and the new pipe.
Sliplining for trenchless sewer line repair can be used on pipes of all kinds of materials, but the new interior segment of pipe is nearly always made from high density polyethylene (HDPE), although fiberglass reinforced pipe and PVC pipe are occasionally used as well.
Methods for Slip Lining
There are two methods used to install a slipline for trenchless sewer line repair: continuous sliplining and segmental sliplining.
- Continuous sliplining uses one long, continuous section of pipe. This is generally made from HDPE or fusible PVC, since these materials can be welded into a continuous pipe of almost any length. The process does not require open cut trenching to expose the pipe. Instead, only an insertion pit and a receiving pit are needed. In many cases, sewer cleanouts or manholes can be used instead as pre-existing access points.
- Segmental sliplining is quite similar, but does not use one continuous piece of pipe. Instead, individual pieces are lowered in and pushed together.
Advantages of Sliplining for Trenchless Sewer Repair
Sliplining is generally the most cost-effective trenchless solution available. The process is relatively simple, and the tools and equipment needed by NJ sewer service contractors are commonplace and easy to come by. Sliplining can be used in pipes ranging from as small as 4″ to as wide as 42″ in diameter, and is effective for pipe lengths up to 3,000 feet.
The installation process is quite fast, and the environmental impact is minimal. Sliplining, like CIPP sewer relining, has the advantage of taking advantage of existing infrastructure, reducing the labor and cost. Instead of digging up, removing, and replacing a damaged sewer line, it can be rehabilitated successfully. After sliplining, the pipe can remain viable for decades to come.
Slip Lining’s Limitations
Sliplining does have a few limitations. One issue is that the new pipe is often significantly smaller in diameter than the old pipe. If it’s used for trenchless sewer line repair, a bit of excavation will still be needed to reconnect the pipe.
Design Considerations for Sewer Pipe Sliplining
When considering sliplining for trenchless sewer pipe repair, there are several important design considerations that engineers and contractors must bear in mind. A few of these engineering considerations include:
- Pipe diameter. The largest feasible pipe liner diameter is generally selected, in order to reduce the pipe diameter loss associated with sliplining. The size and condition of the original pipe will pose limitations in this regard. A polyethylene liner for sliplining will generally have an outside diameter of about 10% less than the original pipe. This provides adequate clearance for inserting the new slipline, while maintaining over 75% of the original flow capacity.
- Liner wall thickness. In non-pressure pipes like main sewer lines, the principle load on the pipe is the hydrostatic load when the water table rises above the top of the liner. Mathematically, Love’s equation is used to show that a free-standing pipe’s ability to withstand hydrostatic loading is a function of the pipe wall’s inertia and the modulus of elasticity of the pipe material. Love’s equation can thus be used to calculate the critical buckling pressure for a specific pipe construction. Designs are selected that provide a safety factor above the maximum expected hydrostatic load, preventing pipe collapse.
- Flow capacity. Another concern is the impact of sliplining on the existing pipe system’s hydraulic capacity. Two equations are commonly used to compare the new line’s flow capacity against that of the original pipe. The Manning Equation is used for gravity flow systems, while the Hazen-Williams Approximation is used for systems other than gravity flow systems. Despite the inevitable reduction in pipe diameter associated with sliplining, this issue is actually offset by the extremely smooth surface of the polyethylene liner. The reduction in the Manning Flow Coefficients and Hazen-Williams Flow Coefficients in most common sewer pipe materials will actually maintain flow capacity at or near its original value.
Sliplining & Other Trenchless Solutions for Sewer Repair in NJ
Need sewer line repair? Call us any time at A1 Sewer & Drain Services for fast, reliable, effective NJ sewer services, at 201-645-0888.