In the era of modern building and plumbing materials, you no longer have to rack your brains over how and where to place a convenient and discreet plumbing system. Standard rigid pipes have been replaced by soft flexible hoses enclosed in a durable housing. These parts last for many years, provided the right choice and operation.
Peculiarities
Flexible eyeliner has a number of features, among which the positive ones easily stand out. But negative nuances should also be mentioned in order to avoid an unpleasant aftertaste, a waste of time, effort and money.
The advantages of this flexible eyeliner:
- complete tightness and protection against leaks;
- saving space, allowing you to install additional interior items or equipment without having to worry about bulky pipes;
- ease of changing the location of an object connected with a flexible liner;
- refusal to use a welding machine;
- protection of the hose from water hammer (if a pressure surge occurs in the water supply system, a high-quality flexible line is protected from rupture and water leakage);
- ease of installation and operation (all basic work can be done independently).
Flexible hoses are typically used for various plumbing connections. Most often it is used in bathrooms (connecting a toilet, faucet, boiler to water) and in kitchens.
As for the negative assessments of flexible hoses, most often users complain about problems that arise as a result of improper installation of the hose. To avoid this, experts advise purchasing products only from a well-known manufacturer. Also guaranteed purchase good quality will be a thorough inspection of the product in the store (before you purchased it).
When choosing, you need to pay attention to several important points.
- The weight of the eyeliner should not be lighter than a feather. If you pick up exactly such a product, immediately put it back in its place. At best, this hose will last you a couple of weeks after installation.
- A flexible liner should bend easily in different directions. If you have to make an effort to change the shape of the hose, you can safely put it aside and take on another one, since this one is made of low-quality technical rubber, which can simply crumble from bending.
Another significant drawback is the short service life of the plastic fitting. To accurately choose exactly the right eyeliner, consider the main characteristics of this product.
Specifications
Today, there are two categories of flexible water connections: extensions and adapters. The second are standard hoses that connect the necessary devices to the water supply: sinks, toilets, showers and boilers. They usually have a length of up to 60 cm. Extensions are an auxiliary hose that is connected to an adapter to provide water to the most remote areas.
The service life of any supply hose depends both on the initial quality of the product and on the correctness of its installation and operation.
When purchasing a flexible bathroom liner, pay attention to the presence of colored stripes on the reinforced surface:
- red indicates the possibility of using only hot water;
- blue can only be used in cold water supply conditions;
- both stripes immediately indicate that the hose can be installed to supply both hot and cold water.
Thus, when connecting a tap or toilet to places where only cold water is always used, you can use all three types of flexible hoses. If we are talking about a mixer with two temperature modes, a boiler or a radiator, the use of hoses with a blue stripe is strictly prohibited.
Flexible hoses with a yellow stripe along the entire length of the hose are also available for sale. They are intended only for connecting users to gas supply and have special impregnations and lubricants inside, which are unacceptable for use with water, especially drinking water or for washing. The water that passes through this hose is considered technical and contains impurities hazardous to human health.
It is worth dwelling on the main types of flexible hoses that exist on the construction market today.
Species
Modern manufacturers offer wide range connecting water pipes OK. They are classified according to the type of braid, internal filler (main tube), type, quality and size of fittings. Let's look at the most common division, based on the type of braid.
According to this characteristic, flexible liner can be:
- reinforced;
- bellows
The first is a rubber base (quality products are made from durable rubber) covered with steel braiding. In this case, the casing of such a hose can be made of different materials. For example, galvanized steel and aluminum occupy a leading place among analogues. This is explained by the low price - and nothing more. Such braiding is absolutely short-lived; it practically cannot withstand the average water pressure in the water supply system and breaks down very quickly. This should not happen, because the upper skin of the rubber hose is designed to strengthen it and prevent water from escaping.
In terms of quality and durability, the best braid is considered to be made from durable stainless steel wire. She provides reliable protection internal rubber hose. According to manufacturers, the service life of such liners reaches ten years or more.
Nylon braiding is a reinforced treatment of the water hose that can withstand even the maximum pressure in the system.
By choosing reinforced braid for flexible hoses, you automatically receive the following benefits:
- installation speed;
- ecologically clean materials manufacturing;
- high strength;
- flexibility.
The second type is an elastic corrugation made of stainless steel. Bellows hoses last longer and have higher technical characteristics.
There are two modifications of corrugated elements:
- with a specified length;
- with variable footage.
For the first, manufacturers immediately determine standard sizes, ranging from 20 cm to 80 cm. The step in the length of the product is 10 cm. The second has a floating range over which it can be stretched. For example, on sale you can find bellows liners with variable lengths of 150-250 mm, 200-350 mm and others. It is worth considering the fact that the maximum stretch is indicated for reference - it is not advisable to stretch the eyeliner that much.
The quality, strength and durability are evidenced by the use of bellows hoses for industrial purposes. Very often, this type of liner is used when connecting sprinklers - ceiling-mounted fire extinguishing devices. The main nuance lies in the plumbing system. A sprinkler installation is a whole network of pipes that constantly contains water under pressure. Therefore, choosing a particularly high-quality eyeliner material comes in handy.
Among the disadvantages of bellows flexible hoses is their noisy operation at high pressure in the water supply system. Despite the fact that this does not happen often in modern apartment buildings, some users recommend using it as little as possible in private properties.
Fittings are usually supplied with flexible hoses. Often these are brass fittings or nuts that come in various shapes and sizes. To select the correct mount, it is necessary to measure the diameters of the pipes in the room where the installation will be carried out.
Plumbing previously consisted of ornate intricacies of pipes, tubes and adapters. But today, thanks to flexible hoses, it has become possible to install devices that use water supply in the smallest rooms. The angled flexible connection allows installation even in hard-to-reach places. Thanks to the peculiarity of its mounting, it can be positioned close to the wall and thus increase the usable area of the room.
Dimensions
The main parameters of flexible hoses are the diameter of the hose and its length. In this case, the caliber is important not only in the tube, but also in the fittings. For example, modern flexible eyeliners are manufactured with a maximum diameter of 1-2 inches. And the most commonly used ones have parameters of 1/2, 3/4 and 3/8.
As for the length of the reinforced or corrugated hose, each manufacturer has its own. In addition, it is practically individual for each individual case. If we consider a stationary liner, then the maximum length is 60 cm. In corrugated sliding models, this indicator can only start at 500 mm, and finish within 5000 mm. The latter are extremely rare, mainly on an industrial scale.
Manufacturers: review and reviews
The most popular today are flexible eyeliners made in Italy. They have proven themselves in the construction market, and many users are happy to note their advantages.
One of the most popular Italian trog brands today is Parigi. According to customer reviews, the products of this brand are highly durable. The manufacturer guarantees the service life of reinforced flexible hoses from 3 to 5 years, while bellows products can last more than 7 years. Special attention Italians pay attention to detail: fittings and nuts are made of high-quality nickel and have a service life of more than 10-15 years. Product prices are high, which approximately 60% of users consider the main disadvantage.
Mateu is a Spanish manufacturing company that has established itself as a high-quality manufacturer in the mid-price segment. In sets of faucets for the kitchen or bathroom, you can often find flexible hoses with a metal braid from this particular company. They also produce their own products in large quantities. brands for large construction hypermarkets.
Another feature of the Spanish manufacturer is the production of reinforced connections using PEX hoses. According to the descriptions of professionals, this type of hose has a maximum service life, since they are made of cross-linked polyethylene. The operation of such material in some cases reaches 50 years. Another feature of the PEX hose is its versatility: flexible hoses with such a base can be used to connect both complex devices (for example, heating systems) and simpler ones (cold and hot water supply).
The domestic plumbing industry is also not standing still. A large number of high-quality, but more affordable products are produced by such manufacturers as “Giant”, “Monolith”, “Aquatechnika”. Users note large number advantages of these eyeliners. But still, approximately 50% of respondents insist that some of the technical characteristics specified in the product data sheet do not correspond, but on the whole they remain satisfied with the purchase.
In order for each part to function correctly and for as long as possible, it is necessary to strictly follow the rules for connecting and installing elements. Despite the fact that even a high school student can handle this process, you should take into account some expert advice during installation.
Connection rules
Connections between water supply systems are carried out using special mounting fasteners. As mentioned earlier, these are fittings and nuts. The hose must be attached freely, slightly sagging, so when choosing the length, rely on a large number. As for the fittings themselves, they come in different diameters (0.5-1.5 inches) and different shapes. If the water pipe and the connection have different diameters, a special adapter comes to the rescue, which can be easily found in all plumbing stores.
Let's look at the basic rules for installing a flexible water line.
- Before installation, or even better before purchasing, perform a complete inspection of the fittings (fasteners). Check whether the gasket is in place and the condition of the threads and braid.
- After installation, it is necessary to connect the water supply to the system and check the operation of the line for leaks within 30-40 minutes. If a leak does appear, try tightening the nuts a little tighter. But you also need to be careful not to overdo it, so as not to spoil the fastening.
- The bend of the hose is allowed in a ratio of no more than 5-6 diameters of the outer tube.
- Shlag is very sensitive to high temperatures, so try to avoid using the product in unfavorable conditions.
- Twice a year it is necessary to check the tightness of the installation and inspect the external condition of the flexible connection.
- If the hose length is not enough, you can purchase a special extension. To avoid metal corrosion due to electromechanical reaction, it is necessary to use pairs of the same material.
- Despite the service life specified by the manufacturer, it is recommended to replace flexible hoses at least once every 3-5 years.
Flexible connection to the mixer is one of the most common elements used for the installation of plumbing fixtures. There are a huge number of different flexible hoses on the market, which makes choosing the right part difficult.
We want to help you understand the features and characteristics of the connections, especially if you intend to install the mixer yourself.
Flexible hoses for connecting plumbing fixtures
Purpose
Connectors made of flexible material are used to connect various plumbing fixtures.
In general, the scope of application of these products is much wider; they are found in almost any pipeline:
- gas,
- technical,
- automobile, etc.
However, within the framework of our article, we consider only the plumbing segment of their use.
So, a flexible lead is used to connect the following devices:
- Taps and mixers;
- Boilers;
- Shower cabins;
- Washing machines;
- Dishwashers;
- Pumps and pumping stations;
- Gas water heaters and boilers;
- Toilets, bidets, toilet installations.
Why has this type of pipe become so widespread? Everything is very simple: using a flexible hose you can connect any device without connecting steel or plastic pipes exactly to the point of connection, because for this you often have to not only cut and weld metal, but also ditch the walls.
Moreover, any inaccuracy will lead to the fact that the work will have to be redone or the device moved, which is highly undesirable.
In addition, the faucet is often connected in a hard-to-reach area, especially in small bathrooms with a clutter of pipes and various appliances. The use of a flexible supply eliminates any such problems, since it can be laid almost anywhere and along the most winding route.
At the repair stage, you just need to remove the water sockets from the wall or floor near the intended installation location of the washbasin. Then you simply select the appropriate length of liners and connect the mixer to the pipes.
Important!
They cannot be used as a replacement for main lines. It is also undesirable to use them in heating systems to connect radiators.
Device and materials
The flexible inlet for the mixer is designed very simply - it is a rubber tube into which fitting bushings are inserted on both sides. From above, the connection between the pipe and the bushing is pressed with steel crimp. The product also has external reinforcement in the form of a braid of metal or polymer wire.
Couplings with internal threads (cap nuts) or fittings with external threads are used as fittings.
- Most often, a nut-fitting assembly (designated g/w) is used to connect the mixer.
- However, on sale you can find a nut-nut (g/g) version.
- Sometimes fitting-fitting (w/w).
The most typical standard nut size is ½ inch, fitting size is M10.
Often there is an option with a 1:2 inch fitting; you also come across a 3:8 inch nut (you have to use an adapter fitting to connect it). Models with a long fitting are common and popular among plumbers, as it is more convenient to connect them to the mixer from the bottom of the sink.
IN quality models hose fittings are made of sanitary brass (Cu Zn39 Pb3). It can be pure or nickel plated. The crimp sleeve is made of stainless steel (GOST 08Х18Н10 or AISI 304).
Important!
In modern construction stores, you often find products with fittings made of a silicon-aluminum alloy (silumin).
This is an unacceptable option, which can be destroyed even at the installation stage, so you should not buy it.
You can easily determine what the nut and fitting are made of: if you scratch nickel-plated brass, the bottom of the groove will be yellow. Silumin will remain monochromatic. In addition, aluminum alloy is much lighter than brass.
The hose itself must consist of ethylpropylene rubber (EPDM), a non-toxic rubber approved for transportation drinking water. This material is elastic and can withstand peak pressures of up to 50 atmospheres.
Here, when choosing, you need to smell the product: if it emits a characteristic unpleasant smell of synthetics, it means that the hose is made of technical toxic rubber, which, moreover, easily breaks and crumbles when bent strongly.
The union nut must be equipped with a sealing gasket, and the fitting must be equipped with one or more rings. These gaskets and rings should also be made of ethylpropylene rubber.
The outer braid in normal products consists of stainless steel or polymer fiber. Such liners last from 8 to 20 years and can withstand operating pressures of 10 – 20 atmospheres.
However, there are models on sale with aluminum braiding, and sometimes the reinforcement consists of ordinary galvanized steel.
Important!
Aluminum braiding will last a maximum of 2 - 3 years, steel braiding can rot in a week.
As a result, the hose may burst, and petty savings on the quality of the liner will cause you a lot of serious problems.
The length of eyeliners usually ranges from 30 to 200 cm, but if desired, you can find almost any size. Flexible connections also sometimes include bellows - tubes made of corrugated stainless steel. They are more durable and reliable, but their price is higher.
Despite the fact that the installation instructions for the products are incredibly simple, certain rules must be followed when connecting them:
- Before connecting, be sure to inspect the product for defects, breaks in the braid, the presence of sealing gaskets and rings;
- When choosing a hose, choose a length so that it is not stretched, and the turning radius was no less than 5 - 6 of its outer diameters;
- During installation, bends are not allowed, it is better to make rings instead;
- It is strictly forbidden to twist the tube along the longitudinal axis;
- The threaded connection of the nut and fitting does not require sealing with tow or FUM tape, its role is played by rubber rings and gaskets;
- The nut is tightened by hand until it stops, then tighten the wrench half a turn, to a maximum of 270 degrees. Over-tightening risks cutting through the gasket, which leads to leaks.
Important!
Buy only high-quality products made from materials that meet the standards.
Saving can be costly.
Conclusion
The use of flexible connections allows you to connect a wide variety of plumbing fixtures to the water supply. When installing mixers, they are often completely irreplaceable, so it’s time to choose suitable model you should take it seriously, which the video in this article will help you with.
A flexible stainless steel water connection is one of the most practical and reliable ways to solve the problem of connecting two sections of pipeline in a production workshop, kitchen, bathroom or toilet.
What is flexible eyeliner
Often, when constructing a water supply route or repairing it, it may be necessary to give a section of pipe mobility, the ability to bend and move in a given direction.
As a rule, this need arises when connecting the final consumer of water: toilet, faucet, water heater, dishwasher etc. A similar problem arises when laying water communications in areas in hard-to-reach places.
In both cases, flexible eyeliner comes to the rescue. Modern plumbing technologies provide two types of these devices:
- A rubber hose with a metal or plastic braid.
- A bellows-type pipe is a flexible corrugated hose made of stainless steel.
Both methods have proven themselves positively and successfully cope with the tasks assigned to them. And yet, stainless steel has a number of clear advantages that are simply not available for hoses made of rubber, due to physical properties material.
Features of use
The features of a mobile stainless steel hose include its unsurpassed reliability, versatility and long service life. Stainless steel provides a number of advantages that are not available for pipelines made from other materials:
- absolute inertness to the chemical effects of detergents and sanitary products, often used in bathrooms, catering units, and production shops;
- resistance to oils. Unlike rubber or polymer products, stainless steel pipes do not change their qualities under the influence of technical and edible oils, present in your kitchen or production;
- safety. If we are talking about a pipeline, the purpose of which is to supply drinking water, this is an important property. Studies have shown that the level of microflora in stainless steel pipes is several times lower compared to steel, plastic or rubber.
- unsurpassed abrasion resistance, the ability to withstand high pressure in the water supply system, for example, when connected to pumps or water treatment filters;
Important to know: a flexible stainless steel hose is able to withstand huge temperature changes from -55 to +700 °C, and at the same time maintain its physical and operational qualities.
- are used to supply hot and cold water, as well as water steam with temperatures up to 450°C, which makes this type of pipeline indispensable for the construction of baths, saunas, and laying heating systems, connecting heating boilers, etc.
Main selection criteria
When choosing a flexible hose for water supply, the main thing is not to make a mistake with the diameter. A narrowed diameter section causes pipe vibration and violates the design characteristics of the entire water supply system. To avoid this, experts advise using the following simple rules:
- the minimum diameter of the hose for connecting the toilet is 10 mm;
- a sink, shower mixer or washbasin is connected to the water supply system with a liner with a diameter of 15-20 mm;
- To connect the faucet to the bathtub, it is recommended to use a liner with a diameter of at least 20-25 mm.
It is also important to consider the length of the flexible pipe. The criterion for choosing the correct length is the absence of unnecessary bends and stress on the hose during its installation.
Interesting fact: Many manufacturers of liners do not limit the warranty on the service life of high-alloy stainless steel and brass fittings, and the service life of fluoroplastic gaskets is stated to be at least 30 years.
The issue of selecting the necessary gaskets is relevant. So, for a cold water supply pipeline in standard apartment building The most common flat rubber or silicone gasket is quite suitable; for hot water supply it is better to use a paranitic gasket.
For water pipes that are used to provide water at extreme temperatures, and in pipelines high pressure It is recommended to use a gasket made of fluoroplastic or copper.
Avoid typical mistakes The following rules will help when installing the supply hose:
- Try not to bend or stretch the sleeve unnecessarily.
- Do not allow the hose to twist when connecting it.
- Avoid overtightening the nuts, this will preserve the integrity of the sealing gaskets.
- Do not allow the hose to bend closer than 50-70 mm from the fastening nuts.
- It is better to form the bending configuration before the fastening begins, and not after its completion.
- Use spacers with a thickness of at least 2.5 mm.
Please note: the minimum bending radius should not be less than the parameters established by the manufacturer.
The only significant limitation in the practical application of a flexible water supply made of stainless steel is its higher price compared to other materials. However, the listed positive qualities are able to compensate for this deficiency.
For more information about flexible eyeliner, watch the following video with tips on operation and selection from a specialist:
At the final stage of plumbing work, faucets, shower cabins, wall-mounted toilet and a bidet or other equipment. This can be done using a rigid, bellows or flexible liner. The first option is much more reliable than the last two, but more labor-intensive; in addition, its execution requires not only the presence of a specialized tool, but also the skills to work with it. Therefore, bellows and flexible hoses (for example, hoses for kitchen faucets with a pull-out or pull-out shower head, shower, etc.) are more practical in everyday life.
First of all, it is necessary to emphasize that although this option for supplying water is considered budgetary, it is quite reliable, provided that the materials are correctly selected and the connection technology is followed.
In essence, a flexible water supply is a rubber hose (the same as a watering hose) placed in a tight-fitting braid made of metal threads. Its main purpose is protection against mechanical damage, both external and internal. The latter may occur due to water hammer. In accordance with the standards, such connecting hoses must be designed for a pressure of at least 10 atm.
Below is an example of a herringbone faucet connection for kitchen sink with flexible hoses (A) used for supplying cold and hot water.
Please note that the sink siphon is connected to the sewer with a corresponding flexible connection (B).
Species
These water hoses come in the following types:
- for connecting the washbasin mixer, shower cabin and other equipment to hot water. To identify them, red threads are added to the braid (“A” in Fig. 2);
- for connection with cold water supply pipes. Their braid contains threads blue("IN");
- universal, allow connection to any type of water supply. The braid of such pipes is marked red and blue (“C”).
Rice. 2. Hoses for cold and hot water, as well as universal ones In addition, the eyeliner differs in the braid material, which is reflected in certain characteristics, namely:
There are pipes where the hoses are made not of rubber, but of rubber; such products are more reliable, but also much more expensive.
As additional protection, the braid can be coated with a silicone layer; according to manufacturers, this can extend the service life up to 20 years.
Despite the fact that it is also physically flexible, it is customary to distinguish this type of eyeliner as a separate type, due to significant design differences. The peculiarity of the bellows liner is that the shell is a metal corrugation, strong, but at the same time flexible; in addition, there is no rubber hose inside.
It is also worth noting that the fitting together with the terminal clamp are connected to the corrugated hose by welding, this significantly increases the reliability of the design. The service life of products of this type is at least 25 years, and they can be used to work with process environments heated to 250°C. As a rule, corrugation is made of stainless steel, but there are VIP category plumbing fixtures where brass and copper are used for this purpose.
This is a new type of eyeliner, and at the moment no non-original products have been noticed on the market. As for the price, it is significantly higher than conventional connecting hoses.
Installation of connecting hoses
Having dealt with the types, let us consider for general reference the typical design of a flexible liner.
Rice. 7. Design of flexible pipes for mixers The product consists of the following main elements:
- Sealing gaskets to ensure the tightness of the connection and prevent leakage “A”.
- Brass or steel nipple "B".
- Rubber or caoutchouc hose “C”.
- Aluminum, stainless steel or nylon “D” protective braid.
- Press the sleeve (clamping the nipple) “E”.
- Connecting fitting (steel or brass) “F”.
- Union nut "G".
The liner is manufactured with three types of connections: nut-nut, fitting-nut and fitting-fitting. Standard sizes for nut – 1/2“, for fitting – M10. Sometimes you may come across a non-standard connection, for example an M8 fitting or a 3/8“ nut. In this case, you will need an appropriate adapter for a kitchen faucet or other equipment.
The length of flexible hoses can be from 500 to 2000 mm; we recommend choosing the appropriate size so as not to install extension connections.
Note that the fitting can be short or long. The latter is more convenient to connect the mixer.
How to choose a faucet hose?
- Availability of a label with the indicated technical characteristics, this will prevent mistakes. Make sure the diameter and type of fastener matches your equipment.
- Be sure to pay attention to the weight of the product; if it has an aluminum braid, the hose will be much lighter than one that uses steel (in most cases, such products have a fitting of questionable quality). As practice shows, they quickly fail, literally within six months, or even earlier.
- You should discard the liner if it is equipped with a plastic fitting; such a mount is not designed for the load required for domestic purposes.
- If the hose is insufficiently flexible, you should also not purchase it, since this sign indicates poor quality. As a rule, this causes several microcracks to appear in the braid, which can cause deformation.
- Pay attention to the sleeve press; stainless steel should be used as the material for them. It is important that their tubes hold tightly - this is an indicator of high-quality pressing.
- Check the design of the union nuts; if they are very thin or light, it means that this is a low-quality product and there is a high probability of problems when using it.
- Low-quality rubber has a sharp, characteristic odor; if you find one, discard this model, since such material will begin to leak quite quickly.
- When choosing hoses for hot water, do not go wrong with color coded, they must be with a red or red-blue thread; those with a blue mark are not suitable.
- Choose an eyeliner of the appropriate length; it is not advisable for it to sag or be stretched.
- Many branded devices (for example, Damixa or Hansgrohe) include 50 cm hoses. To connect a faucet in the kitchen, the length is quite enough, but to connect other equipment they may be short, for example, the standard placement above the bathtub is 150 cm. In this case, you can remove them and screw on the liner of the required length or use it as an extension cord. The last option is not entirely successful. This is due to the fact that an extra connection will appear in the extended hose, which means reliability will decrease.
- Which product to choose, imported or domestically produced, does not really matter; we note that our products are sometimes better and more reliable than foreign ones.
How to change a hose on a faucet - step-by-step instructions
Let's say we are faced with the task of replacing a Grohe faucet in the kitchen or bathroom; all the necessary plumbing equipment has already been purchased. The tools for this purpose will require a gas wrench (you may need two pieces) and fum tape.
We tell you how to replace a Grohe faucet; this is done according to the following algorithm:
- We turn off the water supply. If this is not done, repairs may be required, both for you and for your neighbors below.
- Carefully pull out the old device; to do this, you need to unscrew the liner from the kitchen faucet. Do not apply much force in order not to damage the thread.
- If you are installing a faucet for a sink, we fix it on it (for a bathtub it is attached to special racks). Please note that some branded faucets have a special nozzle on the inlet with a mesh that acts as a filter; do not forget to install it before tightening the inlet.
- We wrap fum tape around the thread, after which we should tighten the underwater hoses.
- If you are installing a bathtub or kitchen faucet with a pull-out shower head, then screw the adapter onto the spout and connect the supplied hose (for the shower head) to it. Wherever there is a thread, we use fum tape.
- At the final stage, we turn on the water supply and check each faucet hose to ensure that nothing is leaking anywhere. If everything is in order, then the installation can be considered successful. Otherwise, it is necessary to close the water supply taps again and check the connections. It is quite possible that water is flowing due to the fact that the rubber seals on the supply hose (“A” in Fig. 7) are not installed or because there is insufficient layer of fum tape on the threads. You will need to disassemble the connections (disconnect the liner) and check, correct the error and tighten the connection.
If you need to connect a flexible connection to household plumbing (regular or built-in type), a bidet with a separate supply, a flush-mounted toilet tank, etc., this is done according to the same principle as replacement (omitting the point where the old faucet is unscrewed).
Many people are familiar with the situation - the flexible hose on the faucet or toilet cistern burst, and all the floors below are flooded.
Unfortunately, the problem is quite common, so today I want to touch on this topic in detail.
Let's remember where it began.
There has always been a need for flexible hoses. Many minds were haunted by the thought of how to make the installer’s work easier and speed it up, and as always, “foreign” manufacturers were the first to think about this, while domestic ones stubbornly produced the “herringbone” mixer, which can be safely described as: “well, , try to connect!
Eyeliners, as in the photo, 
so familiar to us today, in fact, appeared literally in the last decade, having previously undergone a number of changes - at first a copper tube with union nuts, flared at the ends, was produced. For me, this is an ideal, reliable option, but from the point of view of achieving maximum flexibility, it left much to be desired. 
The “minds” strained themselves and developed plastic ones, the principle is the same, but they also equipped them with plastic nuts, they proved to be disgusting - they burst on the body. As a result, they were equipped with brass nuts, and the material was improved. 
As a rule, such liners were used during state construction, and only when connecting cold water supply to toilet flush tanks, our craftsmen, having obtained this miracle through “pull” (it was impossible to find in stores), easily installed it with hot water, and since the material was not designed to operate at high temperatures and accidents often occurred.
Having realized this, the “craftsmen” went further - they began to use oxygen hoses, pressing clamps onto brass fittings. The fittings were sharpened on factory machines, in the quiet of the authorities. The matter can be said to have been put on stream; on the market it was possible to purchase this fitting with the necessary threads (external, internal, proper diameter). At the same time, another type of flexible hose appeared - a high-pressure hose used in hydraulic installations. Believe it or not, people managed to assemble all the wiring around the apartment (house) from such hoses, although there were difficulties connecting union nuts with pipe threads. 
The fact is that the threads here were metric, and connections had to be made through specially machined adapters. This material was highly durable, but the downside was technical rubber, so the water coming out of the tap had an unpleasant smell.
The next step as a flexible connection was the use of metal-plastic pipes. I note that this material was widely used until the water supply was completely replaced with it, eliminating the ferrous metal, but that is not what we are talking about today.
Conditions and rules for installing flexible hoses.
So, we came to the eyeliner that we see everywhere today. It is universal, that is, it is used for both cold and hot water supply. It consists of a rubber hose inside and a metal braid on the outside, produced in various lengths - from 15 centimeters to 2 meters. It ends with union nuts or fittings with external threads of various diameters.
But…
1. Initially, this device was conceived as a connection between water pipes and plumbing fixtures, nothing more, but inventive guys, in order to save money and not overwork themselves, make almost all the wiring, and let’s be honest - all of it! ...I've seen enough.
Make no mistake!
Assurances about performance for 5 or even 10 years are a marketing ploy by manufacturers, and the indicated figure on the tag is just a figment of wild imagination. There is also a statement about insurance of the eyeliner! Honestly? — I have not heard of cases of compensation for losses!
2. The material used in the production of the hoses is absolutely identical; accordingly, the service life in cold and hot water supply is sharply different.
3. The service life depends solely on the characteristics of the line, that is, as indicated above, on the temperature, plus the pressure in the system. We understand, right? There is a system with pressure not exceeding 2.5 - 3 points, and there is 7 and higher.
4. The thickness of the hose wall is no more than 1 millimeter.
5. In addition to the above, it is very important to follow the installation rules:
a) installation by tension is not permissible;
b) when tightening the nut, it is not permissible for the hose to twist after it;
c) if it is necessary to make a ring, then the ring should be as large as possible in diameter.
The mixer comes with instructions indicating the rules for connecting the flexible hose, and it also contains a diagram. 
The following picture is an emergency situation: 
This is the trend in our construction. “Foreign” manufacturers happily supply their plumbing fixtures with these connections, but during installation they often use only the following connection: 
Flexible eyeliner on the verge of failure.
This begs the question: - Why not put it?
Bet! Just don’t be lazy to monitor the water supply system, periodically pay attention to the condition, visually and by feeling.
1. If protruding “hairs” of wire appear on the flexible eyeliner, then this is a harbinger of an accident, because if it sticks out, then the same thing happens inside the braid.
2. If brown spots become noticeable, it means that microcracks have appeared in the rubber hose, which means that a break will occur.
Pay attention to the water supply of your home and avoid a lot of troubles.
3. When leaving your home for a long period of time, turn off the water supply, use the taps at the inlet for this. If you trust one of your neighbors, leave the keys to your apartment in case of an accident.
Video: Real service life of a metal braided hose
Perhaps these articles will be useful to you:
If you have a “sad experience” of flooding due to a flexible liner, share it in the comments. Remember about those around you, perhaps your knowledge will help others avoid problems in the future!
Good luck to the readers in their personal lives, and to the installers in their work, with respect
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