A modern way of installation of house gas pipeline

Radmil CZ s. r. o., gas installation company from Vracov, was contacted by an investor with a request to build a house gas pipeline in a family house in Polešovice. The original intention was to use PE plastic pipes for the exterior (underground) part and the subsequent transition to copper pipes inside the building.

After watching the presentation of the MERABELL GAS PROFI system, they decided to try out in practice what benefits a possible change in technology can bring them. When comparing the costs of installation material, it turned out that even a higher purchase price per meter of stainless-steel piping does not necessarily mean higher total material costs. In this particular case, the price for 21 m of GAS PROFI piping, KOPOFLEX® protector and two nuts was even a few hundred crowns cheaper than the original budget for the combination of PE and copper, where a significantly larger number of transition and connecting elements would be needed. In addition, there is no need to build inspection openings for detachable joints along the route.

Technical design

The required pipe dimension DN25 / 5/4” was selected using online pipe calculator www.merabell.com/calculator. A 30m coil of yellow MERABELL GAS PROFI pipe with a diameter of DN25/5/4” (M00129) was selected. A KOPOFLEX® protector with an outer diameter of 50 mm was used for the exterior part of the piping.

The piping runs from the main gas shut-off valve at the plot boundary to the technical room in the basement of the family house, where the appliance (gas boiler) will be located. The length of the entire gas piping from the main gas shut-off valve up to the boiler is 21 meters in total, and thanks to the MERABELL GAS PROFI sheathed pipe, it was possible to build a line without a single joint. This significantly speeds up the installation itself of the gas piping and, in addition, eliminates the possible threat of leaks in the joints along the route.

Main benefits of GAS PROFI pipes

The MERABELL GAS PROFI pipe is equipped with a robust yellow protective jacket made of PE (polyethylene). For pressing purposes, this jacket can be easily removed from the ends with the help of MERABELL cutting knife (M0304). After pressing the nut, it is recommended to re-insulate the exposed pipe ends with vulcanizing tape (M0321).

The MERABELL GAS PROFI system is certified according to the ČSN EN 15266 standard (Stainless-steel pliable corrugated tubing kits in buildings for gas with an operating pressure of up to 0.5 bar). This EU standard allows the pipe to be routed in a wall without a protector, underground and through a building structure in a protector, when passing through a peripheral wall in a protective pipe.

Excerpt from standards and technical regulations

Source TPG 70401:
It is necessary to use stainless-steel pipes according to EN15266 for the construction, repairs and extension of house gas pipelines.

Source EN 1775:
Article 5.2.5 prescribes that joints made of stainless steel-flexible pipes may only be made by persons with special training and reference is made to informative Annex E for instructions on how to join this type of pipes.

Part E2: Only a pipe and fitting system that meets the requirements of EN 15266 should be used.

Gas distribution systems consisting of stainless-steel flexible pipes run underground:
When installed below ground level, the pipes must be placed in a protector, one end of which is led out into the space (cabinet, niche, etc.) so that a gas leak can be checked. A sufficient solution is to lead out one end of the protector, with the other side being designed as a sealed end. The unsealed end of the protector must be secured against inflowing water, e. g. during the rain, etc. The depth of laying the pipeline below ground level must be at least 600 mm. If the minimum installation depth of 600 mm below ground level cannot be observed, the pipework must be mechanically protected against any impermissible loads, e. g. by a protective pipe.

Recommended installation procedure

  • prepare excavation with minimal depth of 80 cm and fill it with sand
  • insert the protective pipe into the passage through the peripheral masonry (for DN 5, min. inner diameter should be 40 mm)
  • measure the length of the piping from the main gas shut-off valve up to the appliance (including internal pipeline)
  • prepare the protector for underground part of the distribution system
  • prior to laying into the trench, slide the protector onto the pipe in a free space (be careful not to damage the PE jacket by careless handling, contact with coarse and sharp objects)
  • place the pipe with the protector in the trench and pass it through the wall into the building
  • thread a nut on the piping, press the end of the piping, fit the gasket and install into the cabinet with main gas shut-off valve
  • make a backfill up to the height of 30 cm and lay a warning film
  • fill up to ground level

Project assessment

Despite minor delays during installation, which are completely natural when using the new installation technology for the very first time, the assumption of significant time savings has been clearly confirmed. In this particular case, the use of the MERABELL GAS PROFI piping system has reduced the installation time from 5 to 6 hours for two installers to 2.5 hours! From the point of view of safety, it is important that a house gas pipeline without a single joint along the route was built.

With comparable material costs, MERABELL GAS PROFI is clearly a more efficient solution than the originally designed PE/copper combination due to its significant reduction in installation time and higher safety.