Sliplining has been used for over 70 years, and effectively, it is placing a new pipe inside and existing pipe. This technology is one of the methodologies that PW Trenchless specializes in. In fact, PWT was the first contractor in BC to use this type of pipe in the repair of a 100 year old sewer which runs through a Victoria graveyard.
Many types of pipe are suitable for use internally, but HDPE (high-density polyethylene) is the most common. Sliplining also uses PVC and FRP (fiberglass-reinforced pipe) and once the new Carrier pipe is installed within the Host pipe, concrete is pumped in to fill the void and provide structural rigidity and strength. The finished pipe restores structural integrity and stops infiltration. The new pipe is smaller in diameter than the previous Host pipe and this may prove unsuitable for some applications where increased flows have occurred over time.
The new Carrier pipe can be installed as one solid piece pulled in place or in sections and pushed into place. For smaller diameters, HDPE pipe is often used, but for larger diameters, either CSP (Corrugated Steel Pipes) or GRP pipe (Glass Reinforced Plastic) are used. PW Trenchless also uses rectangular GRP pipe from time to time, as was the case to line a large box culvert storm sewer in the City of Richmond.
Some complex projects have internal bends and elevation changes that can only be completed using GRP pipe. These GRP pipes can be moulded into complex shapes to accommodate any variety of bends.
Regardless of the method, sliplining is considerably less intrusive than excavating, removing and replacing existing pipes. Many large culverts are under roadways and highways and there never is a good time to close a major arterial roadways to install pipe via open cut methods.
The scope of work encompassed the rehabilitation of approximately 380m of 36" (914mm) diameter steel water pipeline for the Douglas Rd. Main No. 1 section, from Delta Ave. to Beta Ave. in Burnaby BC. The selected method of rehabilitation was …See Project
PW Trenchless and the City of Victoria engaged in the Rehabilitation of an almost 100 year old Sewer. Victorian era Victoria B.C. quickly outgrew it's existing cemetery by the early 1870's. The City purchased 12 acres from Robert Burnaby Ross Bay …See Project
While rehabilitating the Trans Canada Airport Culvert, it was decided to employ a full Sliplining method in order to repair the second culvert. New culvert pipes that are slightly smaller than the existing culvert were delivered to the south end …See Project
An alternate tendering process where the contract is awarded to one entity which comprises both engineering and contracting.
Because PW Trenchless Construction offers such innovative solutions for underground utilities, it is often beneficial for the owner to request solutions based on a performance specification. This allows PW Trenchess to offer unique solutions while working with equally innovative engineering companies.Learn More
New installation methodologies include HDD & traditional open cutLearn More
In this day & age of pipe systems reaching the end of their projected lifespan, pipe replacement and pipe rehabilitation have become major fields of engineering.
PW Trenchless Construction provides viable options such as pipe bursting, loose fit lining and internal pipe re-construction whether partial & fully circumferential.Learn More
The aging culverts under roads and highways in many case have reached the end of their engineered life-span. We consider the rehabilitation or replacement of these culverts to be vital to our built environment.
PW Trenchless has been a pioneer in working with MOTH, railway companies and municipalities in developing rehabilitation methodologies for the hundreds of thousands of culverts that currently exist in BC. We have offered solutions in both procurement and construction from design-build to sliplining, invert rehabilitation and full circumferential relining.Learn More
Often pipe failure can be concentrated to one section, for various reason, leaving the rest of the pipe in good condition. The repair of these localized failures are know as external point repairs (EPR's).
EPR's demonstrate PW's ability to work as both a trenchless and civil contractor, completing EPR contracts using our civil contracting skills and assisting other pure trenchless contractors who only have the capacity to work in an existing pipe.Learn More
Pipe upsizing is the fundamental concept of pipe bursting.
The vast majority of pipes are less than or equal to 200mm in diameter, but with today's densification practices of urban design, there is a major demand to increase current capacity to handle extra flow. Pipe bursting provides the ideal solution to this issue, particularly in an urban setting .Learn More
Horizontal Directional Drilling is a low impact Trenchless construction service where pipe is installed in a shallow arc along a bore path which has been created by a drilling rig. Often the terms Horizontal Directional Drilling (HDD) and Directional Boring are used interchangeably, but in our industry we use the word “boring” when we utilize smaller sized drilling rigs with small diameters for short crossings in the hundreds of feet, and we use the word “drilling” when we utilize larger rigs with large diameters for long crossings in the thousands of feet.Learn More
When you join PWT, you become part of a community of people who are engaged in the most innovative practices in the Trenchless Industry. We have been instrumental in setting up a scientific method for cities to gain carbon offsets/credits from their use of trenchless construction. This system has been reviewed by the BC Government and has been approved as of December 2018. We expect to see it in common use shortly.