1. Appointment of tow and how it works.
2. Varieties of sealing materials.
3. Method for sealing pipe threads with tow.
In plumbing work, tow is used to seal pipes and transitions connected by threads. It is made mainly from flax waste and is a coarse fiber of small size. If the tow is wound correctly, leakage protection will be provided throughout the life of the pipeline. Answering the question of how to wind tow on a thread, it should be said that the quality of workmanship prevents the risk of a leak in the plumbing system.
There is a gap between the threaded connections through which water freely exits the pipeline. If there is a properly laid plumbing tow in it, then the gap becomes smaller, and in the process of water penetration into such a connection, the flax swells and the leak stops.
Variety of sealing materials.
The main materials that create an airtight layer between threaded connections include:- plumbing tow;
- FUM tape;
- liquid FUM.
Silicone is used as additional material to tow, but by itself, due to its properties, it will not be able to provide reliable protection of the connection from leaks.
FUM is a thread winder consisting of a Teflon tape that is not wetted by water and creates a water-repellent layer in the joints.
Liquid FUM is a one-component sealant of blue color, upon contact with air, it slowly hardens and forms a sufficiently strong and dense filler that prevents water from flowing out of the system. But, if when using the above materials, pressure testing of the water supply can be done immediately, then after applying the liquid FUM, before checking the system, you need to wait a certain time, depending on the diameter and ambient temperature.
Method for sealing pipe threads with tow.
High-quality thread winding is carried out using the following materials and tools:- pipe lever wrenches in the amount of two pieces;
- plumbing tow;
- FUM tapes.
We will consider the procedure for obtaining a high-quality tight threaded connection using the example of combining a union nut (American) with an external thread of 1 inch and a check valve.
From the tow we separate a strand with a length approximately equal to 5 - 7 turns of a diameter of 1 inch and a density indicated in the photo.
We apply the resulting workpiece to the beginning of the connecting element of the American, while its thread should be directed towards you, and wind it clockwise, along the turns and vice versa. We bring the end of the tow to the beginning of the thread and with our fingers, clockwise, smooth it down. As a result, it should turn out as in the photo.
Then, on this part, we wind the FUM clockwise so that it completely overlaps the plumbing linen and lies on it in 2 - 3 layers.
Teflon tape prevents the tow from turning and moving off the part. Making money on the American check valve and with the help of keys we tighten them until a noticeable load occurs.
Such a combined thread winding, with appropriate skill, almost always ensures a reliable connection of two detachable elements of the pipeline. When all components of the system are assembled, it is necessary to pressurize it at a pressure of approximately 1 bar and inspect all threaded connections for leaks.
When using low-quality parts, the amount of winding should be slightly reduced, since during the swelling of flax, forces arise that can lead to damage to the part.
Some people ask: what is best for sealing threads, fluoroplastic sealing material (FUM tape) or sanitary tow? This debate has been going on for a long time, because it is impossible to give an exact answer.
For each specific type of procedure, its material is suitable. And every product can be great. alternative to another. But the goal is the same - to make the connection airtight. Therefore, let's look at plumbing tow, its specifications, as well as the process of its winding.
Linen is a popular winding material. The old name is tow. Linen is an environmentally friendly material that does not cause any harm to human health. The product does not require certification, therefore, it is possible to seal the drinking water pipeline.
Additional material, which is also needed for the impregnation of sanitary tow, is environmentally friendly. Thanks to impregnation, this material will last a fairly long period of time. Linen is a public product. The product is sold in absolutely any plumbing store, so finding it will not be difficult.
Consider the advantages and disadvantages of this material in detail.
Flax Benefits
The advantages of this product:
- Small cost. Tow has the smallest price tag in comparison with other windings. Therefore, at the time of purchase, it is better to pay attention to the quality of sanitary tow. If flax is sold in the form of a pigtail, then this is a quality material. If in the form of a tight bay, then this indicates a low quality.
- Versatility in use. It can be used for any type of connection if the winding is carried out correctly.
- During swelling, the winding in volume becomes larger. This means that if the connection starts to leak, the material will immediately close everything. Small leaks will be closed.
- Resistance to mechanical influences. Only flax allows you to orient plumbing fittings more accurately. You can make one turn back, while the tightness is not lost.
Disadvantages of flax
There are also cons:
- In addition to tow, it is necessary to use other means, for example, grease, sealed paste, silicone and other products. If linen is an organic material, then it can rot due to the influence of water and air. Air enters during repairs or maintenance, which must be carried out every year. And the listed products can interfere with this process.
- It is necessary to carry out preliminary preparation of the thread. Most manufacturers who produce fittings make pre-made threads for plumbing tow. She has notches. If they are missing, then they must be created. This can be done with pliers, a file or a hacksaw. They are necessary so that the plumbing material cannot slide along the turns.
- If the connections are made of brass or bronze, then during winding it is necessary to work carefully and carefully. If you put a thick layer of winding on such connections, defects will appear on the threads. It may be that the thread even breaks.
- During the winding of this organic material, strict rules must be observed. In addition to carving, you must first prepare the plumbing material itself. It is necessary to impregnate it with some substance to prevent future decay. It is necessary to carry out winding, observing the direction. Wound against twisting. The ends of the linen must be brought out of the thread, then they should be pulled. Hold with your finger and scroll.
- It is also worth noting that the additional materials that are indicated above do not prevent the destruction of the connection. If you use silicone to glue different elements of the connection, then it will be extremely difficult and even impossible to separate them later. If flax is used without the use of additional materials, then rust appears on the winding, which will pass to steel.
Comparison with FUM tape
Sealing means sealing the water supply. If it is necessary to seal pipes for cold water, then in this case linen and ribbon are equally suitable. You just need to do the winding correctly. But if it is necessary to seal pipes made of plastic or metal-plastic, then it is better to opt for the FUM tape.
The main advantage is that with the help of tape the work will go much faster, since installation is quite easy. Also, the threads of the fittings are even, so the use of plumbing tape will be much more effective.
However, the fum tape loses its effectiveness if it is necessary to seal a pipe whose diameter is more than 20 millimeters. Linen should be used for pipes with this diameter.
Pipeline for hot water sets its own terms. The product should not only seal perfectly, but also have good resistance to high temperatures. Fluoroplastic sealing material (fum-tape) in this situation is not the best option.
During winding, the FUM tape is split into fibers, which fill all the voids, thereby preventing the penetration of water. The high temperature of the water can affect the fibers so that they shrink, eventually leading to a leak. Tow has a high level of resistance to hot water.
Also, do not forget about the small price of tow, even with the use of additional materials. Plumbing tape is an expensive winding. If you need to carry out work of large volumes, then you will feel a significant difference in cost. But installation is much easier and faster with the use of fum tape.
It may be that you need a combination of two plumbing materials. The turns of the FUM tape can be laid using tow fibers. Or in a completely different way, that is, two turns of plumbing tape can be wound from the top of the tow. This procedure is rarely practiced due to distinctive features mount.
Mounting a linen product requires certain skills from a person. Installation of fluoroplastic sealing material will be performed even by a beginner.
The procedure for winding sanitary tow
How to wind tow on a thread? Before winding the tow, it is necessary to pre-prepare the thread. Since the surface of the thread is most often flat, the winding will begin to slip and bunch up. And sealing is not possible. The thread must have notches, thanks to which the fibers can catch on the threaded surface. The winding will not slip and will provide high-quality sealing.
You can make such notches or notches with a file or needle file. If you do not have these tools, then you can use pliers. With the help of them it is necessary to squeeze the thread in a circle. But it is better to purchase a thread on which manufacturers have already made notches.
Then a strand of fibers must be separated from the pigtail. Choose a strand that will fit in thickness. The material should not be too thick, but not too thin. The strand of fibers should not have lumps. If there are lumps, they must be eliminated. The winding process can take place in different ways.
Many specialists twist the product before winding, others braid thin pigtails, and some wind it loose. It depends on the person himself. The overall result will be the same.
At first, additional material can be applied to the thread, then the dry fibers of the strand can be wound, and then one layer of the product is applied. You can immediately wind the impregnated product. The result will also be the same. It depends on convenience.
How to wind tow correctly? In any chosen option, the winding of the turns is carried out in the direction of the thread. Outside the thread, the end of the strand of fibers must be clamped with a finger. The first turn is applied in the form of a "lock". Be sure to wind the strands tightly, do not leave gaps. As the winding is completed, the strand of fibers must be glued to the companion product closer to the extreme part of the thread. The winding of the tow on the thread is done crosswise.
These are the most common and popular methods for sealing threaded connections. All of them are great, but you need to follow certain rules and nuances.
Outcome
Flax is a popular material in plumbing, designed for threaded connections. The wound tow will provide high-quality tightness of the connection. Tow plumbing is cheap even with the additional use of related materials. Properly carried out winding eliminates the possibility of leakage due to swelling of the product itself.
Most people will choose linen as it is environmentally friendly. However, before winding, it is necessary to carry out additional work related to the preparation of the thread. It is necessary to make notches for winding a strand of fibers. When sealing joints made of bronze and brass, care must be taken not to damage them.
Each person can carry out installation, but you must strictly adhere to the rules and then you will not have problems.
Here's how much to eat modern materials to seal the joint, and the good old flax does not give up its positions.
What is his task? Plumbing linen allows you to fill in all the free space inside the thread as tightly as possible. To withstand mechanical loads and temperature deformations during operation.
What is needed for this? Master skill. quality material and quality carving.
Thread. Or rather, her preparation. You can be a good craftsman, but get a leak on an unprepared thread. The thread must be notched. Flax should cling to something when twisting the thread into the coupling. On smooth threads, there is a high chance that the linen will slip into the end of the thread.
Therefore, on a smooth thread, the notches will have to be applied by yourself.
You can scratch the thread for this. Use for this pieces hacksaw blade, broken drills, files, etc. But be careful, you can easily get hurt.
I bite the thread with plumbing pliers. It turns out quickly and accurately. Someone may object that this way you can squeeze and ruin a thin-walled fitting.
Very good. I'd rather crush him than he'll collapse inside the clutch later.
Yet. Before winding flax, it is necessary to assemble the joint dry, without flax. First, you will see how the thread is screwed in. May be tight or skewed. Secondly, count the number of turns. When screwing on elbows, tees, taps, eccentrics and other oriented fittings, this helps a lot.
Screwed in? Have you checked? Did you count the turns? Fine. We take linen.
Linen is in braids, in balls, on coils. How it is wound and sold, there is no difference. The main thing. Linen must be clean. That is, it should not contain debris and tangled lumps.
Separate a strand of flax. It is difficult to say what the thickness of the strand should be. It all depends on the diameter of the thread and the length of the flax. The landmark is something like this - after winding, the thread should not be visible.
There is a lot of debate about where to start winding - from the beginning of the thread or from the end. Absolutely all the same. From where the hands are sharpened, from there and shake. Who is comfortable. I wind from the beginning, along the thread.
Now apply sealing paste. For example, I take Unipack paste. Not because it is the best, but because we sell it everywhere. Previously, about 20 years ago, I used paint. Then, succumbing to fashion, smeared silicone sealant. As soon as sealing pastes appeared on sale, I immediately switched to them.
The tightness of threaded connections depends entirely on the packaging. And although only at first glance, winding flax on a thread is not difficult, as in any other business, it also has its own subtleties and secrets.
For example, it often happens that the tow is cut off by a thread or, on the contrary, climbs out. In this case, it is necessary to scratch the thread, making small notches on it.
So, how to properly wind the flax on the thread, the better to lubricate the tow in the process of sealing the thread and will be discussed below.
Today, there are two most popular materials for sealing threads, these are fum-tape and flax - also known as tow. Both the material for packing threaded connections have both their positive and negative sides.
The advantages of flax for winding threads are inexpensive cost, durability in use and some other advantages. For example, linen swells when it comes into contact with liquid, and it often happens that a small leak closes up the next day.
It is more convenient to work with tow and you can’t do without it when winding cast-iron threads and other threaded connections with large diameters.
To know how to properly wind flax on a thread, you need to remember the following:
- The winding of flax on the thread is carried out clockwise or in other words along the thread, in the direction of its twisting.
- After sealing the thread with tow, its surface is lubricated with a special paste to prevent decay during operation.
- To prevent the linen from slipping off the thread during its winding, small notches are made on threads made of non-ferrous metals (bronze, brass, copper) using pliers or plumbing crabs. Black metal can not be scratched.
If you still don’t know how to lubricate tow for threads, then you should understand that both special purchased pastes, such as Unipak or plumbing sealants, and other lubricants, in particular, lithol and grease, are suitable for these purposes.
It is not very convenient to work with the latest lubricants for tow, since you can’t wash your hands from them later, and the effect on flax during its operation may not be as positive as when using special lubricants and sealants.
To properly pack the thread with flax, you need to take a small amount from the whole “braid”, and from the beginning of the thread, start laying flax in each turn clockwise. At the same time, it is important to monitor the uniformity of winding flax so that each thread contains approximately the same amount of it.
You should not wind flax tightly around the thread, because in this case it will be very difficult to twist it later, and the risk that the thread will burst increases significantly. This is especially true for non-ferrous metal threaded connections, which have very thin walls and low strength.
It is normally considered that after winding the tow on the thread, its upper edges are barely visible. In this case, the installation of a threaded connection with your own hands can be done quite easily and without excessive effort.
As a rule, it is not worth saving with the amount of tow by winding threads from ferrous metal - cast iron or steel. This is especially true for cast-iron threads, from which, after winding the tow, it simply peels off.
After the linen is wound on the thread, its surface is lubricated with a sealant, while the paste must be pressed into the tow, and that in turn into the thread. Only you need to do this again clockwise, or in the direction in which the flax is wound.
The debate about what is better to use as a sealant for threaded connections (winding) - flax or fum-tape - has not subsided for more than one year. This situation is explained by the fact that it is impossible to give an unambiguous answer to this question. For each type of work, either flax or fum tape is preferable. And often the recommendation of one does not exclude the use of an alternative sealant. If plumbers cannot come to a common opinion among themselves, then what can we say about non-professionals? But after all, even mere mortals sometimes need to connect something with each other. And it's hermetically sealed. Let's try to sort out the recommendations "on the shelves". On the properties of the fum-tape and the technology of its winding. And today our review is devoted to flax, or tow, for plumbing.
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Sanitary flax: cheap and cheerful
Linen is a classic winding. Sometimes it is called tow in the old fashioned way.
Advantages of flax for plumbing work:
- Low price. Cheaper than any other winding. When buying, you need to pay attention to quality. Good flax is sold in a pigtail or not a tight bay, has no lumps, is clean (light in appearance).
- Versatility. Suitable for any kind of connections. Of course, with the right winding.
- The ability to increase volume in the process of swelling. That is, if immediately after the connection there is a small leak, it very soon "closes" itself. Flax fibers get wet and, swelling, block small leaks.
- Mechanical resistance. The only material that allows you to more accurately orient sanitary fittings. It is possible, if necessary, to make a half-turn-turn back without loss of tightness.
But there are also disadvantages:
- Mandatory use of related materials with it (lithol, grease, fum-let, sealed paste, silicone, oil paint). Linen is of organic origin. And like any organic matter, it has a tendency to rot, especially under the combined influence of water and air. And the air enters the water supply or heating systems during the repair or routine inspection, which should be carried out annually. The accompanying material is designed to prevent rotting.
- Requires special thread preparation. Many manufacturers of fittings make the threads on them already prepared under the winding of flax. The threads are notched. If they are not there, then they need to be applied to plumbing (with a file, pliers, less often with a hacksaw). They are needed so that linen, in the process of joining, does not slip along the threads and does not come true in a bundle.
- Requires care in brass and bronze connections. Too thick a layer can break the thread, cracks will appear.
- Plumbing flax is the only material that is very demanding in terms of winding rules. In addition to the already mentioned preparation of the thread, you need to prepare the flax itself: impregnate it with related material to prevent decay. Then wind, observing the direction of the threads, that is, against winding. Bring the ends of the fibers out of the thread area, tighten and, holding them with your finger, screw the connection onto the thread, tighten.
- The disadvantages include the fact that the accompanying materials (not all) prevent the dismantling of connections (for example, to replace part of the system, connect new elements or in the event of a leak). Silicone and paint stick the parts of the joint together so that the process of separation can be quite difficult, sometimes simply impossible. The same problems arise when separating steel elements, when, incorrectly wound flax (or without accompanying material) as a result of decay, allows the occurrence of rust in the threaded connection.
Which is better: linen or fum-tape?
When it comes to sealing threaded joints, the first thought that comes to mind is plumbing. When installing a cold water pipe from steel pipes neither flax nor fum tape has clear advantages. The main thing is to wind the seal correctly. But when this water supply is mounted from or, a fum tape is preferable. Its advantage in this case is due to speed. Non-metallic plumbing is mounted faster than steel. And to reduce the speed of installation only because of winding (and winding flax is more difficult and longer) is not effective. In addition, the thread of the fittings is even and neat, and in such conditions the fum tape is more effective. But it should be remembered that when connecting fittings with a diameter greater than 20 mm, the fum-tape is inferior in sealing quality. In such connections sanitary flax turns out to be more efficient.
Installation of plumbing for hot water and heating dictates its requirements. Including in terms of winding. In addition to the presence of water in the pipes, it must be borne in mind that it is hot. That is, the winding must not only be airtight, but also withstand the effects of temperature. Fum-tape in this regard has proven itself not in the best way. At the moment of connection, the fum-tape splits into fibers and they clog the voids of the connection, clogging the passages for water. Under influence high temperatures, which must be present in the heating system and are possible in the hot water system, these fibers are compressed. Often this is enough for a leak to occur. Linen is resistant to temperature.
If we take into account other properties of these materials, then it is worth noting the low cost of flax, even taking into account the accompanying material. Fum tape is more expensive. Not by much, but when carrying out large-scale work, this difference can be significant. But the use of fum tape, as already noted, increases the speed of installation.
There are also cases when the combination of linen and fum tape is the most effective. Coils of fum tape are laid with flax fibers. Or vice versa, one or two turns of fum tape are wound over a linen winding. The decision on this is not often made by plumbers, in view of the particular conditions of installation or operation of the pipeline.
And the last thing - winding flax requires a certain skill from the plumber. Fum tape is not so demanding on this process.
Photo: depositphotos.com How to wind flax on a thread?
Before you start winding flax, you need to prepare the thread. The fact is that on a clean and even thread, flax in the process of joining may not be able to hold on, slide off, stray into a bundle. Of course, there can be no question of any sealing in this case. The threads should have notches for which the flax fibers will catch. This will allow the winding to stay in place and ensure a tight seal. These notches are applied with a needle file, a file, and if possible, with a hacksaw. IN last resort you can strongly squeeze the thread in a circle with pliers, the ribbed jaws will leave notches on the threads. Fitting manufacturers often produce threads already prepared for plumbing linen.
Then a strand of fibers is separated from the flax pigtail. It is important to choose a strand of suitable thickness so that the winding is not thin and not too thick. There should be no lumps in the strand: if there are, they must be removed. Some plumbers twist a strand of flax fibers before winding, someone weaves thin pigtails, and someone winds the strand as it is, loose. It doesn't matter who cares. It does not affect the final result.
There are two options for the next steps. You can apply an accompanying material to the thread, wind dry flax fibers and then apply another layer of material. And you can wind the strands of flax already impregnated with the accompanying substance. In terms of efficiency, there is no difference between these methods. The result will be the same.
In any case, you need to wind the turns of flax in the direction of the thread. The end of the strand is clamped with a finger outside the thread, the first turn is made with a “lock”. That is, it is superimposed with a cross to clamp the end. Then the strand is wound as tight as possible, coil to coil, without gaps. At the end of the winding, the end of the strand is glued to the accompanying material closer to the edge of the thread.
