How to make a hiden gas pipeline in an apartment building

The problem was solved by a pipe under the plaster

The old steel gas pipeline of an apartment building in Otrokovice, which dates back to the 1940s, no longer meets the safety regulations. Condition of these pipes was so critical that a small gas leak could already be smelt in the corridors of the house. It was therefore necessary to build a completely new distribution system. However, the company Martin Dolanský - GASEDO, selected for this contract, encountered a major problem. No plans of the original gas pipeline have been preserved, and even the current inhabitants of the house had no idea where the pipelines were exactly routed.

Based on consultations and technical support from MERABELL, the installation company decided to build the main spine of the pipeline from solid stainless steel pipe routed in risers in the corridor of the house. They chose the flexible stainless steel MERABELL GAS PROFI pipe for gas distribution lines leading from the gas meter to the apartment units. They are coated with a special PE sheathing and can thus be installed under the plaster without the need to use a protective sleeve. The easy formability of the MERABELL GAS PROFI pipe allows the pipe to be routed in the shortest possible way, thus greatly simplifying the shape of the pipe and safely avoiding existing water and electrical wiring.

Why did Martin Dolanský - GASEDO decide to use the yellow MERABELL GAS PROFI flexible pipe?

Speed and cost of installation - assembling a gas pipeline from conventional materials such as copper would require the use of dozens of different shaped elements with the need for precise crimping. Preliminary planning of the shape of the pipelines alone for the purpose of approximate estimation of the required fittings would be a relatively time-consuming activity, and even then would only be indicative for a contract of this magnitude. There would very likely be repeated unproductive trips to the wholesaler for missing fittings. Let's not even talk about material costs. Stainless steel bellows pipe is slightly more expensive than copper pipe, but because it eliminates the need to use fittings for the actual piping, stainless steel becomes a cheaper option, especially for more complex shapes. On top of that, there is also a significant time saving thanks to the speed of installation. The use of the flexible stainless steel pipe MERABELL GAS PROFI absolutely speeds up the planning of material purchases. All you need is a long enough coil of pipe, a nut, a gasket and possibly a few pieces of nipples. The ability to easily bend the stainless steel pipe at any angle by hand brings radical time savings, as it eliminates the need to crimp tens or hundreds of fittings that would be necessary with copper piping. In this particular case, the company estimates time savings of up to 40%!
The resulting design - the MERABELL GAS PROFI pipe is coated with a yellow protective PE sheathing and thus meets the ČSN EN 15266 standard, which allows the pipe to be routed under plaster even without a protective sheath. In this case, it could therefore easily be placed in the wall so as not to interfere with the appearance of the common areas of the house.
Safety - gas distribution with MERABELL stainless steel pipe can be built with a minimum of joints. Here specifically, the connection is only at the beginning at the gas meter and then at the other end of the pipeline at the gas tap. Therefore, there is no risk of a leak in the route in the future. As the old plumbing rule goes: "the best connection is no connection".
High quality and durability of the piping - the stainless steel bellows piping is partially flexible. Therefore, they are perfectly resistant to possible expansion or vibration, thus avoiding the occurrence of a possible puncture. In addition, the MERABELL GAS PROFI pipe is covered by a 10-year manufacturer's warranty.

Installation procedure

With using of on-line pipe calculator (see www.merabell.com/calculator yellow piping was selected: MERABELL GAS PROFI with DN15 / 3/4”, coil 60 m long. The gas cooker is to be connected by M0020 MERABELL GAS PROFI R1/2”–G1/2” hose, length 100 cm.

PIPE CALCULATOR

The main spine of the pipeline was constructed of solid stainless steel pipe and the side branches of the pipeline were stretched from DN15/3/4" bellows pipe. This was connected with a system joint (G3/4" nut, 3/4" 24/16×2 flat gasket) and a brass reducer to the gas ball valve at the G4" outlet fitting of the gas meter, which was located in the utility room in the hallway of the house. The pipeline was then continued along the surface of the wall and led through the penetration to the corridor, where it was formed into a groove under the plaster. Where the kitchen was located, the pipe was routed through a culvert to the location of the gas stove. The gas pipeline DN15 / 3/4" is terminated by a system connection (nut G3/4", flat seal 3/4" 24/16×2 and transition nipple G3/4" - R1/2") with a ball valve, after which a 1 m long MERABELL GAS PROFI gas hose is connected.

The pipeline construction was carried out by two parties: the first assembly crew of 3 people installed the actual piping and the second crew of 2 people carried out the construction work. Thanks to the ease of construction preparation (the requirements for precision in cutting the groove for the flexible pipe are considerably lower than for the rigid pipe) and the speed of installation (the distribution from one piece of pipe and all the bends are made by hand), the time to build the distribution for one entrance of the apartment building was reduced from the original eight working days to only five days (37.5%).

Within 6 weeks, a gas pipeline was built for 48 apartments in 6 entrances of the apartment building. 360 metres of MERABELL flexible pipe were used.

Benefits of the MERABELL GAS PROFI pipe with protective sheathing

Certification 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.
It is made of high quality stainless steel AISI316L (surgical steel).
It is flexible and allows shaping only by hand.
It is covered with a yellow PE (polyethylene) protective sheathing.
It has a superior 10-year warranty.

Recommended installation procedure

Measure the length of the piping from the gas meter up to the appliance.
Cut a groove in the wall to accommodate the pipe.
Plan the location of sockets used to fix the piping to the wall.
Prepare a protection tube in which the piping is to be passed through the wall.
Pull the pipe in the protection tube through the wall.
Shape the pipe by hand as required and insert it into the groove in the wall and fix it by cement mortar or clamp it in the sockets.
Thread a nut on one end of the piping, crimp the end of the piping, fit the gasket and connect it to the gas meter.
Thread a nut on the second end of the piping, crimp the end of the piping, fit the gasket and install gas lock.
Instal the gas hose into the gas lock.
The grooves with the pipe are then filled with cement screed and structurally repaired.

Project assessment

The installation company took less than 4 weeks to build a completely new gas pipeline for 48 apartment units instead of the originally planned 6 weeks. Thus, the assumption of a significant reduction of installation time was unequivocally confirmed.

It is also important for the residents of the apartment building that this was the last worry and expense because of the gas pipeline. The lifetime of the stainless steel pipe is at least the lifetime of the building itself.

The “clean” final appearance of the common areas of the house, which allowed the pipes to be hidden in the walls of the house, is also notable.