KRAH Technologies

Highest quality standards, from project to construction

HANDLING & TRANSPORTATION

Pipes and fittings have to be transported with appropriate vehicles. During the transport and especially during the loading and unloading they have to be protected against damages. During the unloading the pipes using hoists, only belts, that is safe to handle, should be used. Steel wire ropes, chains as wells as sharp-edged lifting devices should be avoided. While unloading of the pipes with a fork-lift, the forks that carry the pipes should be examined for any sharp edges. It is recommended to wrap the forks with a protecting foil or to use a suitable pipe inside the pipes that have to be unloaded. The pipes should be stored on even ground which is free of stones or sharp-edged objects. The pipes are to be stored in such a way that they cannot deform and are protected against dirt, mechanical damages, and pointed load and this applies especially for the spigot and the socket that is integrated with the electrofusion wires. HDPE Manholes are usually equipped with lifting lugs that welded homogeneously to ensure safe loading and unloading on the site as shown in the picture. All these lugs are homogenously welded to the pipe.

JOINTING

All KRAH pipes are produced with an integrated socket and spigot, which are adaptable to the following kinds of jointing techniques:

  • Electro fusion joint
  • V seam extrusion welding
  • Extrusion welding
  • Heat element butt fusion
  • Flange connection
  • Gasket connection

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Installation & Testing

KRAH pipelines are engineered products. The basic installation for these pipes is based on the worksheet ATV A 127. The basis of the installation procedure is:

• DIN EN 1610 • DWA A 139 E According to EN 1610, the load carrying capacity pipe / ground for earth-laid pipes has to be checked before the start of the installation. This can be verified by the static calculation ATV A 127. While making the trenches, ensure that it is protected from its stability due to the impact of ground water, or other neighboring ground works. The trenches are to kept free of water that may affect the installation process. Trench widths indicated in EN 1610 irrespective as shown in the static calculations are sufficient, which shows that the welding machines can be used without any problem.

The embedding of the pipes considerably rules the load distribution and the pressure distribution on the pipe to prevent from any deformation. It is always recommended to use a compactor to compact the soil to the desired level. All materials which are defined in the EN 1610 can be used for embedding the pipes, materials like washed gravel, crashed gravel, sand, granular ground. The mechanical compaction of the main backfilling directly above the pipe should only be started when a layer of minimum 300 mm is above the apex of the pipe.

Note: The compaction which is determined in the static calculation cannot be reached with wet compaction material with less than 11% of humidity

Standards

The standards followed are as below: Gravity Pipes – EN 13476, DIN 16961 Statistical dimensions – ATV A127 Hydraulic dimensioning – ATV A 110 Pipe Installation – EN 1610, ATV 139 Jointing of the pipes – DVS 2207 Vertical shafts for manholes – BS EN 13598, ASTM F1759 & ATV 127

Availability

The following products are available for your infrastructure: 1. Gravity Pipe (Structural or Solid) from DN 300 – DN 4000, with various stiffness class. Available with all standard fittings or customised. Kindly contact the manufacturer for more details. 2. Manholes and Chambers for Sewer or Storm water network using straight shaft from DN600 to DN 3000, with benching channels oriented according to the requirements for any depth. Where the manholes are used for large diameter directional changes, Tangential manholes can also be fabricated. All the accessories required can be customised according to the needs.