Kramer Direct is pleased to add the Herrenknecht Direct Pipe System to our list of client services
Direct Pipe is a proven, sophisticated hybrid which combines the advantages of HDD and micro tunnelling to allow single pass installation of steel product pipes in diameters from 36 to 60 inches.
Major advantages include:
- Greatly reduces the possibility of hydraulic fracture and inadvertent returns.
- Able to operate in all geologies from sand and silt to gravel, cobbies and hard rock.
- Single Pass –borehole is excavated and product pipeline installed at the same time. No reaming –no pullback.
- Steerable both vertically and horizontally. Capable of managing both uphill and downhill slopes –as well as curved drives along the alignment.
- Requires access from only one side. Ideal for water outfalls and sensitive environmental areas.
- Small footprint –ideal for densely populated or congested industrial settings.
- Lower manpower and equipment requirements.
- Able to launch from surface, a shallow pit or deep shaft.
- Capable of a much shorter and shallower crossing profile, thereby requiring less pipe.
- Fully closed slurry circuit which uses up to 70% less bentonite. The mud system cleans and reuses the bentonite –thereby greatly decreasing disposal costs.
- Our DP System is staffed and operated by experienced personnel under the guidance of DP General Manager Rob Schenker. In addition to hands on DP experience in Alberta, Rob has 30 years of tunnelling, boring and HDD experience throughout Western Canada and the United States.
Pipeline installation in one step
With the unique Direct Pipe® technology, Herrenknecht has opened up new possibilities for installing pipelines in every geology. This method combines the advantages of microtunnelling and HDD technology. In one step only, a prefabricated pipeline can be installed and the required borehole excavated at the same time. This allows speedy and highly economic installation of pipelines with lengths of more than 1,500 meters.
Two technologies cleverly combined
From the launch pit, the soil is excavated using a slurry-supported Herrenknecht Microtunnelling Machine (AVN). It pumps the excavated material through a slurry circuit inside the prefabricated pipeline, to a separation plant located above ground. The pipeline, which is surface staged on rollers and welded to the end of the Microtunnelling machine, the pipe is pushed into the borehole at the same time as excavation takes place. The necessary thrust force is provided by the Pipe Thruster. It pushes the Microtunnelling machine forward together with the pipeline – with a thrust force of up to 500 tonnes in increments of 5 meters. The push force is transferred to the pipeline through the Pipe Thruster’s clamping unit and then to the AVN cutterhead. During excavation, the tunnel face can be controlled consistently and safely using slurry-supported tunnelling technology even in heterogeneous, water permeable soils. Uphill and downhill slopes, as well as curved drives along the alignment, can be managed precisely by guidance systems (U.N.S.).