House Connections/Service Lines

In the last stage of the distribution grids, service lines transport medium from distribution systems into buildings, or plants. These lines pass through inside or outside meters.

Application

House connections and service lines serve essential functions in our everyday lives. Whether it’s delivering potable water for household use or supplying natural gas for heating and cooking, these connections play a crucial role. One challenge in the target applications is integrating meters and pumps, as well as managing the transition created by transition adapters, tapping saddles and ball valves into the network, which depends on local standards. Water house connections have dimensions ranging from d25 to d63, providing water pressures up to 10 bar. Gas house connections, on the other hand, usually span from d20 to d63, with pressure ranges between 25 and 100 mbar (depending on each application).

The quality of house connections and their proper installation significantly impacts their performance. Ensuring leak-free systems and maintaining adequate pressure are key considerations. Additionally, strict adherence to safety regulations and local requirements is vital to safeguard both water and gas connections.

FAQs

What is the preferred jointing method for house connections?

Electrofusion is a straightforward method for joining polyethylene pipes in house connection applications (water and gas). For heating element fusion jointing, plastic pipes are connected using electrofusion fittings until they are permanently joined together. Our electrofusion fittings (couplers, fittings, and saddles) have integrated resistance wires to which electric current is applied during the fusion process. This heats the inside of the fittings and the outside of the pipe to the fusion current temperature, melting them. The measurements of the outer pipe diameter and the fitting correlate to achieve fusion pressure during jointing, resulting in a homogeneous joint. The welding pressure required for the polymer melt is due to the volume increase of the melt and the fitting design. The fusion data transfer of the fittings is carried out using bar codes logged with the fusion device. After cooling, a permanent, homogeneous joint is formed.

Advantages of Electrofusion:

  • Pull-out resistant, so no buttress is required for underground lines
  • Jointing of pipes of the same material types (PE 80, PE 100, PE 100-RC) and combinations thereof
  • Different SDR classes can be welded together
  • No fusion bead on the inside of the pipe
  • Low space requirement due to lightweight and compact fusion devices
  • Fully automatic fusion process with high process reliability
  • Gap-free traceability through fusion protocols and identification of welded components
  • Low investment needed because welding of all dimensions occurs with one fusion device

Electrofusion machines, compact and portable, are crafted from robust materials, allowing use in harsh conditions with minimal space. They offer excellent data storage options and are configurable with little advance training required.

In addition to electrofusion, we recommend using compression connections,  with our iJOINT system. This jointing technology is specifically designed for house connections and service lines in water applications, offering high pressure resistance and excellent pull-out strength. Its innovative design facilitates fast, forgiving, and effortless installation, even in challenging trench and weather conditions. Whether for new installations or renovation work on existing lines, this versatile system delivers reliable results.

 

Is polyethylene suitable for transporting drinking water safely?

Drinking water is the most important form of sustenance, so requirements for the pipes and piping components that transport it are correspondingly high. Pipes, fittings, and valves made of polyethylene meet all the chemical, technical, and hygienic demands required of them. Furthermore, they have already been guaranteeing the reliable transport of gas worldwide for decades. As part of the European drinking water approvals, each PE piping system component is tested organoleptically (for smell and taste without the use of aids) and analytically (chemically) for its suitability for drinking water (e.g. in accordance with KIWA “Publication 94-01” or KTW-BWGL and DVGW worksheet W 270).

Biofilm cannot be prevented and is always present in the drinking water supply network across the board. Independent studies on the subject of biofilm (microbial growth) clearly show that, over an operating period of two years, colonization by microorganisms increases by roughly the same extent for all pipeline materials. However, increased water temperature and minimum flow/dead space are favorable conditions for the formation of biofilm and its proliferation. The use of disinfectant under practical conditions controls the scope of the biofilm formation but does not remove it completely. The testing of our products according to DVGW worksheet W 270 certifies that, from a microbiological standpoint, PE is safe for use with drinking water.

Is it necessary to shut off gas lines when tapping or repairing?

Whether a new installation, subsequent tie-in of mains or service lines – our saddles are faster and easier to use than standard tees. The connection to non-pressurized or pressurized pipes is suitable and allows tapping under pressure.

“Tapping under pressure” or “Hot-tapping” refers to the process of making a connection to an existing pipe while it is still carrying media (water or gas). Instead of shutting off the flow completely, which can be disruptive and time-consuming, new branch connections can be installed without interrupting the flow. This technique is commonly used for extensions or adding new connections to existing pipelines.

When it comes to repairs, whether for gas or water lines, it’s essential to shut off the media flow. There are various options available for this:

  • Closing fittings (gate valve, ball valve, pressure tapping valve)
  • Setting an isolating bladder (to be used with gas, not with water for reasons of hygiene)
  •  Squeezing off gas
  •  The greatest care should be taken when working on gas lines under pressure (strict adherence to national policy).
  • Close to repair points, assemble temporary shut-off devices in all gas-bearing lines.
  • Temporary shut-off device = set isolating bladder.
  • Gas pressure ≤ 50 mbar (for manual bladder).
  • Install gas shut-off bladder against the flow using stop off saddles and bladder removal tools (manual bladder only in an emergency!).

For more information, please have a look at our planning fundamentals.

What kind of local regulations impact the installation of house connections?

House connection installations are impacted by diverse local regulations, which can vary from country to country or even within specific areas. Adhering to these regulations is crucial for establishing durable and dependable connections. For instance, while gas meters are often placed outside buildings for easy access during meter reading and maintenance in the Netherlands, others still involve indoor installation (typically in basements or garages) due to colder climates (f.ex. in Sweden).  When it comes to water house connections, there are also differences in set parameters: In Germany, the DVGW (German Technical and Scientific Association for Gas and Water) sets standards for water connections. These cover pipe materials, installation depth, and meter placement. In Australia, the Water Services Association of Australia (WSAA) provides guidelines for water connections. These address meter location, pipe sizing, and backflow prevention.

With our global presence, we offer specific support to enable each area to create connections for life.

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Georg Fischer Piping Systems (Switzerland) Ltd. - GF International

Amsler-Laffon-Strasse 9

8200 Schaffhausen

Switzerland

GF logo on the headquarters building