Other rehabilitation methods

  • Name – Rehabilitation using "top hat"

Technical description of a rehabilitation method
Other rehabilitation methods
rehabilitation of house drains using „top hat”
according to PN-EN 752-5; 13689; ISO 11296-1; ISO 11296-4, 13566-8.

1. Method description

DrainLCR - Liner (LateralConnectionRepair) system is designed for rehabilitation and permanent sealing of brims and laterals of the main pipeline leading to house drains of diameter up to 300 mm. It uses either LCR top hat or LCR sleeve liners. LCR top hat liner seals the connection in the main pipeline on the brim only, while LCR sleeve is installed similarly to short sleeve.

2. Liner installation equipment

  • sewer cleaning equipment (pressure truck)
  • sewer inspection camera
  • compressor
  • power generator
  • EPROS LCR unit
  • by-passing unit (pumps, hoses)

3. Connection rehabilitation technique

The unit can rehabilitate brims of lateral connections between the main sewer and house drains using so-called short sleeve and, simultaneously, rehabilitate a defined section of the house drain. It also can install an LCR top hat liner. It uses a pre-shaped, flexible tube that functions as a shaping element. The main pipe (packer tube), cylindrical on the side, has an additional lateral tube (bulb tube), positioned centrally at 45° or 90°.

Before installation, the bulb tube is inserted into packer tube with the LCR sleeve or LCR top hat (they have the same shape as the shaping element). Then air is vacuumed from the packer and bulb tubes. It prevents the rehabilitation material (LCR sleeve or LCR top hat) from slipping. 

The assembly is moved to the rehabilitation place using a fiber optic rod; the operation is facilitated with 2 telescopic wheel assemblies. The assembly can be rotated axially in the rehabilitation spot using the wheeled assemblies and a rotation drive. A camera mounted on the assembly is used for its final positioning.

Then a control panel is used for operating the expansion mechanism (Pathfinder). It expands the basket and presses the integrated brim against the pipe wall. Now the packer is withdrawn using the fiber optic rod and the brim is inserted into the lateral connection. If the lateral connection opening is not found, the assembly can be moved, so as the expansion basket fits the lateral opening.

After the positioning the packer tube is inflated, the bulb tube is introduced to the lateral connection and the basket is withdrawn. Insertion is delayed using a HD line released and braked by a winch. Completion of the lateral connection introduction is confirmed with a sound signal. After curing the sleeve, air is vacuumed from the assembly and the assembly can be moved from the rehabilitation place.

Basic advantages of the system

Reliable installation method:

1. Introduction is possible only if the LCR basket is properly positioned.

2. The signal is sound only after completion of the insertion.

Technical advantage: only insertion methods allow rehabilitation on bends and in cases when pipes are dislocated.

Compliance with practical requirements: effective rehabilitation also possible with ground water present and using few pieces of special equipment.

Economical: low investment cost: only necessary packers are purchased.

Practical: light, mobile unit that can be transported in a light truck.

Flexibility: the repair can be done using a pneumatic ram or carriage.

Availability: for easier axial introduction of LCR packers to the sewer, they can be pneumatically positioned at an angle.

  • Name – Chemical resistant mineral liners

Man-accessible pipelines and manholes
Technical description of a rehabilitation method
Other rehabilitation methods
Chemical resistant mineral liners
according to PN-EN 752-5; 13689; 13566-1; 13566-8

1. Method description

The rehabilitation method using chemical resistant mineral liners is designed for rehabilitation of man-accessible sewers and manholes. It is used in sewers that do not require structural support.

The main purpose of the method is to seal the sewer and level the irregularities in the old sewer caused by corrosion.

With regard to sewer environment, the material also meets a range of other conditions which make it suitable for such specific applications, including resistance to sulfates and sulfuric acid, watertightness, steam permeability, etc.

2. Liner installation equipment

  • sewer cleaning equipment (pressure truck)
  • sewer inspection camera
  • by-passing unit (pumps, hoses)
  • platform truck for transporting the material
  • hoisting crane (or container truck with a hoist)
  • pumps for feeding grout
  • sewer ventilation unit
  • pneumatic fretsaw
  • pneumatic jigsaw
  • testing equipment

3. Preparation to installation

Assessment of the sewer’s technical condition

Before starting rehabilitation, the pipeline is cleaned using a hydrodynamic sewer cleaning unit mounted on a truck. Then the pipeline is inspected using a remotely controlled camera. The video footage is used for preparing a detailed digital report on the pipeline’s technical condition. The report is a base for classifying the sewer’s technical condition.

Choice of the rehabilitation method

The rehabilitation method depends on the technical condition class and damage degree. After the assessment of the sewer’s technical condition, geodetic data have to be analyzed, including ground water level compared to the base of the sewer, motor traffic in the area, and other parameters that impact parameters of the selected liner.

Storage and transport to the site

Wykładzina w postaci sypkiej lub workowanej jest dostarczana na plac składowy (magazyn) i stąd, w odpowiednich partiach, przewożona na plac budowy.

4. Instalation of the liner

The order of operations in applying proper chemical resistant mineral lining is as follows:

  1. Clean the sewer of fine and larger solids using the pressure truck (10-20 MPa) and remove manually rubble and stones.
  2. Clean hydrodynamically, using water (70-100 MPa), walls and ceiling of the sewer to remove corroded weakened element of the sewer, grease and other solid deposits.
  3. Prepare the walls and ceiling for applying the mineral liner: remove dripstone, seal cracks, level irregularities using appropriate materials (quick-setting mortar, injected grout, tacking agents).
  4. Spray the wet sewer surface with the mineral liner, using a worm pump. In case of a brick sewer, apply two layers of the liner. The first layer is to fill the joints between bricks and show minor leaks not found earlier. They have to be sealed before applying the second layer. Optimal thickness of the layer is 10 mm and when many layers are applied, the total thickness should not exceed 25 mm.
  5. Dry the floor of the sewer by installing a by-pass and relevant connections. The by-pass can be installed inside the sewer (it operates gravitationally then) or outside it, using wastewater pumps of capacity up to 1,200 m3/h3.
  6. Clean the floor of the sewer using the pressure truck.
  7. Clean hydrodynamically the sewer floor using water or sandwater.
  8. Prepare the floor of the sewer for applying the mineral liner, using other relevant materials.
  9. Spray or apply manually (in oval sewers) the mineral liner.
  10. Remove the by-pass and finish the spots used for its installation. 
  11. The sewer can be put into operation only after 8 hours following complete application of the liner.

5. Inspection

5.1. TV Inspection

After the installation and opening connections, acceptance TV inspection (including VHS or CD recording) is carried out. Inspection report is also prepared.

5.2. Tests

According to PN-EN 13566-1, 13566-8.

6. Correction of flaws

Flaws are corrected using primary material (chemical resistant liner) or other special materials.