The further development of TV cameras to those with very small dimensions (Abschnitt 4.3.2.1) makes it possible today to position packers in laterals of DN 100 to DN 150.

As regards the packers used, it depends on the locality of the application:

• Packers for the exclusive injection in the region of laterals and private domain sewers;
• Packers for the simultaneous injection of a limited region of the lateral and the branch connection to the collector;

These processes, according to the information of the manufacturers, are applicable for sealing leaking and/or cracked sewers or pipe joints, laterals and manholes and also part pipe breaks, whereby in this case the stability must still be ensured.

In the regions of the leaks and depending on the ability of the injection medium to penetrate, the embedment is also sealed and fixed.

The processes can all be used with the materials usual in the sewage …

After taking the section of the sewer to be worked on as well as its associated laterals out of operation and arranging the required by-pass flow, flushing with high pressure flushing apparatus is carried out as dirt can influence the chemical reaction of the two components under certain circumstances.

The tailings of the solvent B left in the section of the sewer are neutralised with a diluted solution A. This work is, of necessity, coupled with a leaktightness test in order to prove the success of the injection. The closed-off section of the sewer can then be immediately put into operation again.

In the Sanipor process, the sewer is cleaned with water and the tailings of the gel are removed. This is possible as the gel only reaches its final hardness …

The personnel requirements for carrying out the fill and drain system are 3 to 5 people.

Besides the equipment required for the cleaning and inspection, sufficient sealing balloons are also required as well as 2 to 4 tanker vehicles with integrated or separate pumps and suction installations as well as a container with tools and testing equipment.

The advantages that can be named are:

• Independence of cross sectional shapes, dimensions or piping materials;
• The sealing of sections of the sewer, laterals and structures in one working pass is possible;
• No structures are necessary;
• Sealing and fixing of the soil in the region of damage with the existence of correspondingly large leaks in the piping and soil that can be injected;
• Few personnel and little equipment required;
• No cross sectional reduction.

Fill and drain system, also called flood grouting or line injection, are characterised by a two-phase injection using the section of the sewer as a conveying or distribution pipe for the injection medium and the leaks as injection openings. The required injection pressure is created by means of backing up the affected section of the sewer or the network region.

Some representatives of this group of processes, in alphabetic order are:

• Rathosan [FI-Ratho] ;

The injection processes utilised in the non-man-accessible region serve the purpose of

• Sealing locally limited leaks for preventing infiltration and exfiltration; and/or
• Replacing the static bearing strength.

In contrast to the internal injection with man-accessible cross sections, in which all works can be carried out manually at the site under direct control, the injection in the non-man-accessible region (with the exception of the fill and drain …

It is usual for joint sealing masses to use the chemical raw material base for characterizing and differentiation, on the basis of which certain important information can be obtained on properties and features. However, it must be noted that many masses on the market contain inactive filler material that can influence the properties under certain circumstances.

According to chemical raw materials, there is differentiated between:

• Polysulfides (also …

One possibility to later seal joints and pipe joints in man-accessible nominal size regions is with the insertion of sealing materials (elastic sealing media and plastic sealing media) in accordance with DIN 19543 [DIN19543:1982] and EN 476 [DINEN476:1997] as well as joint sealing masses [Barte80] [Werse80].

DIN 19543 [DIN19543:1982] has been replaced since August 1997 by EN 476 [DINEN476:1997]. As this latter does not specifically deal with sealing …

The process was developed for the repair of locally limited damage in sewer pipes and sewers with circular cross sections in the nominal size range DN 150 to DN 600 with widths of up to 4.00 mm and ovoid cross sections with comparable dimensions. The process is independent of the pipe material [GSTT1/2].

The dimensions of the resin soaked glass weave depends on the following pipe-specific limiting conditions:

• Type of damage;
• Cover and traffic load;…

Short hose processes are carried out from available manholes.

In preparation for the work, the section of the sewer as well as the connecting sewers must first be closed off and taken out of service. The sewer must be cleaned and the exact positions and dimensions of the respective damage as well as connections must be optically inspected; if necessary, the sewer should also be calibrated. Any flow obstacle that have been found and that could hinder …