The main types of flexible connections for connecting water in everyday life
When connected to a water main, several types of flexible piping are used, which have the following features.
Rubber and PVC hoses
The main advantage of these products is their low price and the ability to work under high pressure - for this they contain frames made of strong threads or metal spirals coated with rubber on the outside and inside. The maximum pressure for which reinforced rubber hoses are designed does not exceed 10 bar. at the temperature of the supplied liquid from -50 to +120 C.
A rarer type of flexible hoses are PVC hoses of high plasticity, which are reinforced with a reinforcing spiral placed inside. Products are lightweight, resistant to aggressive chemicals, not afraid of ultraviolet radiation, have a smooth inner and ribbed outer surface.
PVC hoses are mainly used in industry, they are designed to work with a pressure of about 15 bar., Their main disadvantage is the small operating range of water temperature - from -20 to +60 C.
Fig. 3 Flexible water and gas connection made of rubber
Reinforced eyeliner
It is a soft metal hose with a braid, which can be made of aluminum, galvanized steel or stainless steel, sometimes a rubber tube is placed in a synthetic nylon material (this type is practically not used in everyday life).
Flexible reinforced hoses have the following parameters:
- Products in steel or aluminum braid are designed to work no more than 3 years, the service life of stainless steel hoses reaches 10 years, nylon-coated hoses can last 15 years.
- During operation, aluminum or steel braid withstands pressure up to 5 bar., Stainless steel is designed for 10 bar., Nylon hoses withstand pressure in the system up to 20 bar.
- The maximum working fluid temperature for hoses with aluminum, stainless and nylon braid is 80, 95, and 110 C, respectively.
When choosing braided hoses, they generally prefer products with a stainless coating - they have high performance parameters, and their couplings are made of high-quality non-ferrous metals. In this, stainless steel products differ from cheap types of aluminum, where union nuts and adapter fittings can be made of brittle silumin (aluminum-silicon alloy).
Fig.4 PVC flexible hose
Bellows hoses - design
The main material for the manufacture of the braid of bellows hoses is AISI 304 stainless steel with a thickness of 0.3 mm. During production, it is compressed to a corrugated shape and wound into a spiral. The bellows can be made in the form of a welded joint with a fixed length or by crimping, while the length of the eyeliner can vary within certain limits.
Cap nuts and fittings are usually made of stainless steel and non-ferrous metals (high-quality brass, bronze) with a chrome coating, the ends of the braid of several links are folded into them. Sealing gaskets in connecting fittings are made of rubber or fluoroplast.
Basic rules for connecting flexible underwater hoses
After selecting the product of the required length with union nuts and fittings corresponding to the connected equipment and pipes, underwater hoses are mounted, observing the following rules:
- Before installation, the product checks for the presence of gaskets, the quality of the braid and connecting fittings.
- The hose is fastened in a free hanging position without tension, twisting and sharp bends, the bending radius should exceed the diameter by at least 5-6 times.
- The inlet hose is fastened manually, the presence of leakage is checked after 30 minutes with a dry cloth. In case of leaks, you can slightly tighten the cap nuts and fittings with an adjustable wrench, avoiding pinching the gaskets.
- In order to avoid electrochemical corrosion, it is desirable to make a threaded connection from the same alloys.
- After installation, the tightness of the system is checked for leaks at least once every six months, the need to replace the eyeliner with a braid is indicated by the presence of exfoliated metal hairs on its surface.
Fig. 9 Installing a bellows water line in a kitchen sink
What is a bellows water supply and its scope
A bellows is a corrugated shell made of various materials, which may contain one or more layers and does not lose its physical and chemical properties under the influence of mechanical deformations, internal and external pressure, temperature changes and their combinations.
Easy installation, high performance and ability to dampen vibrations allow the use of bellows water supply in the following cases:
- Connecting household plumbing equipment (faucets, toilet bowls) to the water supply.
- Water supply to showers and kitchen watering cans.
- Connection of equipment for water supply - hydraulic accumulators, electric pumps, boilers, various plumbing fixtures.
- Use in heating systems for connecting storage tanks and radiators.
- For draining water from washing machines and dishwashers.
- For connection to gas mains of gas stoves, household and industrial gas boilers, boilers and so on.
Fig. 2 Bellows flexible hose - main types
Water connection installation
Installation of new equipment is necessary if:
- household appliances or plumbing equipment are connected for the first time;
- a leak of a previously installed product was detected;
- the transfer of the connected equipment is required and the length of the installed piping is not enough.
In any situation, when installing the device, it is recommended to adhere to the following scheme:
- hose preparation. Before installation, it is recommended to straighten it to its full length, check the device for damage and deformation, check the complete set;
- system preparation. Connection can be made only after shutting off the water supply. If individual taps are installed on the risers in an apartment or other room, then the flow is shut off independently. If there are no taps, then to turn off the water, you need to contact the management company;
Individual taps for shutting off water
- dismantling of equipment that has become unusable using a wrench (adjustable) wrench. When removing the liner, be aware that water remains in the device. Therefore, when dismantling, it is necessary to substitute a basin or other container to collect water;
Dismantling process
If during dismantling it is not possible to unscrew the nut due to the formation of rust, then you can use WD-40 liquid or any solvent, which will remove plaque.
- sealing. When installing a new device, it is necessary to pre-seal the threads. To do this, you can use linen thread, FUM tape and other analogues, as well as install the o-ring included in the kit;
Thread seal
- fastening a flexible hose to water pipes and plumbing equipment (household appliances);
- tightness check. If, when the water is opened at full power, no leak appears within 10-15 minutes, then there are no leaks.
How to replace the eyeliner, look at the video.
To prolong the service life of the bellows connection, it is necessary to turn off the water supply during a long period of non-use and systematically check the operability of equipment and devices,used to connect.
Criterias of choice
When choosing, consider:
- device parameters;
- manufacturer.
Basic selection options
The most important parameters that matter when choosing a bellows water connection are:
- hose length. For normal operation, it is necessary that there is no tension when installing the hose, that is, the length is selected taking into account the margin;
- operating pressure and temperature of the device. Bellows hoses from different manufacturers are designed for different operating parameters. The pressure and temperature at which it is possible to use flexible piping are indicated in the technical documentation;
- connection method. Manufacturers produce hoses for connecting water supply of two types: with a nut-nut connection and with a fitting-nut connection. The nut has an internal thread and is usually connected to supply pipes. The fitting is equipped with an external thread and is installed for connection to a mixer or other equipment;
Varieties by connection method
To connect washing machines and other household appliances, liners with an angled nut adapter are used, which makes it possible to reduce the space between the wall and the appliances.
For connecting household appliances
thread size on the connecting elements. Hoses are available with the following parameters.
| Size in mm | Size in inches |
| 15 | 1/2 |
| 20 | 3/4 |
| 25 | 1 |
| 32 | 1 1/4 |
Typical dimensions
Popular manufacturers and their features
The quality of the product largely depends on the manufacturer. Consumer reviews allow us to determine the range of the most popular companies that manufacture bellows connections for water supply. These include:
- Turkish company Veka. G-BEKA connectors can be used to connect any equipment under any conditions. The products are durable. Warranty period of use - 3 years;
- Russian company "AquaProfil", which manufactures products under the brand name Aquaprof. The manufacturer was one of the first to start producing reinforced hoses with an increased wall thickness, which allows to extend the service life and almost completely eliminate the possibility of mechanical damage;
- OSCAR-M (China). Eyeliners at a budget price are of high quality and long service life;
- Witzenmann GmbH (Germany). Products under the Hydraflex brand are distinguished by reliability, but also by high cost;
- Russian company Zubr. Products differ in the minimum cost and high level of durability.
