Cured-in-place pipe

lining is an economic solution of trenchless sewer rehabilitation, which enables the renewal of defective pipelines without excavation. Whether sewers, house connections, conduits or pipelines – the used type of mobile rehabilitation is fast, flexible, jointless and durable.

Cured-in-place pipe. process description

100 - 1.000 mm pipe diameter
water and wastewater pipes, gravity and pressure lines, gas pipeline area of application
preferably egg shaped and circular cross-section pipe profile
up to 250 meters with impregnation on site length
stoneware, fiber cement, cast iron, concrete, PVC, GRP, etc. pipe material
in- and exfiltration, cracks, damages, root intrusions range of application

Cured-in-place pipe. the procedure

Preliminary works like high-pressure cleaning, as well as removal of joint rings and sediments are executed via robot. Laterals have to be measured and dewatering has to be provided.

The mobile RS City Liner is quickly installed on site. Wall thickness of the liner varies from three to fifty millimeters according to static requirements and diameter.

Impregnation of liner (consisting of epoxy resin, polyester needle felt and a polyurethane coating) is executed in a closed truck, with a two-component epoxide resin on site. A water hose with discharge hole is installed at the end of the liner. Thereafter, the liner gets closed and set under vacuum. Impregnation of liner using an automatic dossier and mixing system follows. Adjustment of resin with calibration rollers.

Inversion with inversion tower
The liner is installed at existing manhole or required installation shaft. Preliner is installed with air pressure to avoid contact of resin with soil and create a better final quality. The impregnated liner is fixed front end on the inversion tower and clamped around the inversion ring. The liner everts solely with water (as cool as possible) pressure (around 0,5 bar) with a calibration role speed of around one meter per minute – liner inversion. Through inversion, the liner is turned insight out. The impregnated part of the liner lies against the existing pipeline and the PU-coating, which protects against mechanical abrasion and chemical corrosion forms the insight of the new pipe.

Curing of liner and opening of inlets
When inversion is done, water is heated up to 80°C to accelerate chemical curing reaction time. After compliance of curing time (depending on diameter and total length), water is cooling down to 20°C followed by leakage tests. Then ends of the liners are cut open, water escapes and all inlets are re-opened with robots. We randomly do leakage tests of inlets and manholes on demand. For optical control and documentation of our work, CCTV is executed.

Cured-in-place pipe. advantages

  • installation over manhole possible
  • little loss of cross section
  • load capacity can be heighten or rebuilt
  • water inversion (no incorrect expansion)
  • hot water cured resin
  • good chemical resistance (several resin types available)
  • epoxy resin: resistant and shrinkage-free
  • applicable for drinking water
  • seamless pipe
  • rehabilitation of pressure lines
  • applicable for house connection with curves
  • applicable for long distances
  • open up inlets

Cured-in-place pipe. further information