Jacking pipes are subject to exceptional strain. They have to satisfy the highest demands, meet a set of special requirements and have to be adapted to the size and the properties of the jacking machines. Vitrified clay jacking pipes do just that, since their outstanding characteristics and high-quality technical specifications give rise to:

  • Spigots precise to the millimetre thanks to finishing by cutting, milling and grinding
  • Absolutely parallel facings for evenly spread pressure transmission and distribution of tension
  • Couplings DN 200 to DN 1400 made of stainless steel
  • Profile gaskets (rubber elastomere) on the outsides of the thrust rings, to prevent any ingress of soil into the sealed area
  • Water tightness of joints at least 2.4 bar inside and outside
  • Pressure transmission from pipe to pipe with wooden pressure transfer ring (DN 200 to DN 1400)
  • Assembly of pipes, couplings and pressure transfer rings at the factory
  • Production of bentonite adapters or injection nozzles to suit site conditions. Threaded sleeves and sealing plugs made of stainless steel

The main techniques for the construction of sewers are pilot pipe jacking and microtunneling. Careful ground investigation is the basic condition for both techniques.


Abrasion resistance
am ≤ 0,25 mm
Bending tensile strength
15 to 40 N/mm²
Biological resistance
Fire resistance
Chemical resistance pH
0 to 14
2,4 bar
Compression strength
100 to 200 N/mm²
Elasticity module
~ 50.000 N/mm²
Frost resistance
Hardness (according to Mohs):
~ 7
Corrosion resistance
Working life
100 years or more
Ozone resistance
Poisson’s ratio
Crushing strength, according to diameter:
32 up to 160 kN/m
Pulsating fatigue strength
Jacking forces
up to 6.700 kN
Thermal-expansion coefficient
K -1 ~ 5 x 10–6
Heat conductivity
~1,2 W/m x K
Wall roughness
k 0,02 mm
Specific gravity
22 kN/m³
Resistance to pipe jetting
280 bar
Tensile strength
10 to 20 N/mm²
Vitrified Clay Pipe Systems