Sealing lubricant for threaded connections. What are the advantages of sealing threaded connections
Sealing threaded connections- a rather serious thing. This is the moment to which close attention should be paid in any case, without exception.
After all, threaded connections in plumbing are used almost everywhere. On new-style water pipes, you can still find advanced fittings based on adhesive joints, soldering or special crimping tools, but even in this case it still does not go out of fashion.
And what can we say about the more ancient water supply systems, with which the vast majority of modern buildings are equipped.
In this article, we will answer your question of how to seal threaded connections without spending too many resources on this process.
Article content
Why is sealing necessary?
Many may immediately ask themselves, why is it necessary to additionally seal the thread? After all, you just need to tighten the nuts well, and make sure that there are no leaks anywhere.
However, not everything is so rosy. It just seems that the thread on a pipe or fitting is a reliable and monolithic thing. Of course, by tightening it properly, at first you will forget about any troubles, but this will not always be the case.
Temperature fluctuations that often occur, especially in heating systems, cause the pipe material to contract and expand. The changes are invisible to the human eye and are too slow to detect. Which, however, does not prevent them from creating weak, but prolonged pressure.
Vibrations from the water supply work in a similar way. They gradually loosen the thread, weakening it. And these are only two main factors, but there are also side ones. Down to the quality of the metal itself.
However, there is only one conclusion. Sooner or later the thread will loosen. If you do not check the quality of the tightening, while simultaneously reaching it to the desired positions, then this will happen sooner rather than later.
Well, if you immediately discover and be satisfied. In this case, you will be able to avoid serious trouble.
But what if the pipe is in an inaccessible place? Or too close to household appliances or expensive equipment, that is, when a leak occurs, a significant danger immediately arises.
And you won’t run around the apartment with a key every week, checking whether the next compression nut on the corner fitting is properly tightened.
It is possible to avoid such situations. And in different ways. Let's take a look at them in detail.
Sealing methods
There are several options at once, with which you can make it really reliable. It is unlikely that they will be able to function for decades without maintenance (if you do not use modern solutions), but they will still greatly simplify your life.
In practice, it becomes clear that once sealing the connection even in the simplest way using ordinary flax, this becomes enough for household plumbing.
So, the main methods of sealing include:
- sealing with flax and its derivatives;
- fum-tape seal;
- use of teflon thread;
- application of anaerobic gels.
Each method has its pros and cons. It's hard to pick them all out, but we'll try anyway.
In short, flax is the “grandfather”, an ancient way. They used it even when no one knew about the anaerobic gel. Fum tape and Teflon thread are examples of linen substitutes, they are good, but not in every situation.
Well, the sealing gel has its own number of properties that should be considered more widely, so we will fully reveal its nuances a little further.
Now we will analyze each method separately.
Use of linen
Sealing threaded joints with flax is a rather old technique, but still has not lost its relevance. Its advantages are extreme low cost, availability and acceptable efficiency.
Our grandfathers use linen sealant without further processing. The maximum that could be done over it was to coat it with resin. As a result, a rather tenacious and durable sealed material was obtained, which is easy to mount on the thread, while spending a minimum amount of time.
Now linen threads themselves rarely appear in use. They are replaced with linen treated with silicone, special pastes, etc. Note that not all samples of such seals are suitable for use on food water pipes.
The same flax treated with silicone, according to many masters, negatively affects the quality of the liquid, so you need to be more careful with it.
The sealing process itself is quite simple. We wind flax on a thread, we try to fill each turn with a thread. Then we fix it and twist the connection.
The use of fum tapes and teflon threads
Fum-tape is a sealant made of polyethylene of a brand with such a long name that we will not even mention it here. All you need to know about fum-tape is that it is a great solution when you need to seal joints on ordinary plumbing pipes.
It is moderately cheap, environmentally friendly, easy to install and also easy to remove. A big plus of tapes of this type is that they do not affect the quality of the thread and do not decompose in the process of interaction with the metal. While some samples of flax can increase the rate of corrosion of metals.
The fum tape is simply wound onto the thread, and then clamped by twisting the connection.
Of the shortcomings, it should be noted its not very reliable fixation. Excessive vibration or stress may cause the tape to break or slip out of the thread. That is why plumbers do not recommend using it where the pipeline has loads above average.
Teflon thread - is a nylon or Teflon thread impregnated with unique compounds. It is in many ways similar to linen threads and is just as easy to use. But it is distinguished by increased strength, durability and safety in relation to the carrier inside the pipeline.
Sealing gels
Anaerobic or sealing gels - sealants higher order. The gel is used to seal and protect any connections, including threads on bolts, various kinds of mechanisms, etc.
The scope of their application is very wide. Many car manufacturers process almost all threaded parts with such materials to ensure their tightness and reliability.
The gel not only protects the connection from leaks, it also significantly seals it, increasing the limit load threshold.
If an ordinary bolt can be unscrewed by rotating its head with a pressure of up to 3-4 Nm, in extreme cases up to 6 Nm, then a gel-treated bolt cannot be unscrewed even at a pressure of 10 Nm. And if a high-strength gel is used in the work, then far from everyone will be able to disassemble such a connection.
Sometimes only heating helps to solve the situation. Stories about broken threads and incredible efforts when trying to unscrew an ordinary bolt on an engine frame without prior preparation are by no means legends, but a harsh reality.
Operating principle
Anaerobic gel consists of several ingredients. For the most part, we are talking about high-strength polymers that are able to solidify in a certain state.
AT closed, without contact with air, the gel can be kept for a sufficiently long period of time.
Upon contact with air, it begins to harden, but very slowly, which gives a person the opportunity to use it for its intended purpose. The true one begins at the moment when the gel is in contact with both sides of the thread, while not in contact with air.
At this point, it quickly hardens, becomes extremely hard. The thread is, as it were, monolithic or glued. As a result, unwinding even an ordinary bolt becomes extremely difficult.
Manufacturers produce many models of sealants of this type. The most popular and most convenient way their divisions are by color.
There are sealants
- blue;
- red.
Blue gel is a medium strength sealant. It significantly complicates the process of loosening the thread. And by and large, the processed thread itself will not weaken, except when interacting with prolonged and rather serious loads.
Even in order to simply unwind it, you will have to make a lot of effort. The resistance of the blue sealant can still be overcome manually.
But red is no longer available. Rather, it is possible, but only with additional heating. The red sample gel practically glues the structures together. The substance is not subject to mechanical stress. It is recommended to be used on pipelines with strong vibrations and vibrations.
The only sure and easy way to weaken the action of the gel is to heat it. For a short period, it will weaken, become fluid. Otherwise, such a connection can be called heavy-duty and extremely reliable.
Testing thread sealants (video)
Sealing method
Working with anaerobic gels is easy and simple. You only need to follow a few steps.
Stages of work:
- Clean the thread, prepare all the details.
- Apply sealant to threads.
- If necessary, smear it across all channels. In some cases, it makes no sense to smear the sealant, since it will already spread along the plane of the thread at the moment it is twisted.
- Screw the part, forming a connection.
- Wait a few minutes.
- Check connection for strength.
If it is impossible to unscrew the fitting with medium pressure, then the sealant has seized and everything is in order. There is little that can loosen such a thread, so you can be completely calm. There will definitely be no unexpected leaks and other troubles.
The first aqueducts passed long haul to modern pipelines. Today's systems use reliable, environmentally friendly and durable materials. But even the use of the latest technology is not able to guarantee uninterrupted operation. Installation errors, non-compliance with operating standards and the use of unsuitable materials can compromise the entire system. So, one of the key and most vulnerable elements of the pipeline are threaded connections. For sealing there are various solutions, all have their drawbacks and advantages, we will talk about this in this article.
Sealing problems and their consequences.
The first and most obvious problem that occurs with a poor-quality connection is leakage. But what is much more dangerous is that even a perfectly working, at first glance, plumbing can turn out to be a time bomb. When using low-quality or unsuitable seals, the threads can corrode and break under the influence of chemical, thermal or mechanical stress. Unexpected breakthroughs and the need to constantly inspect connections is not at all what you want to get after installing the pipeline. In order not to make a mistake with the choice and protect yourself, consider existing solutions for sealing in order of evolution. itemprop="video" >Sanitary flax
Linen is a natural material, which means that it is environmentally friendly and without any risk can be used for drinking water. But this quality has a downside - biodegradability and fragility. Linen absorbs moisture, which leads to corrosion and thread failure. Replacement of such connections will be needed in three to four years. A more modern solution is linen with a special paste that protects the thread and thread, increasing reliability. But such a connection will still need to be inspected periodically, since the paste facilitates the disassembly process. The substance is non-toxic, but it strongly stains hands and parts. Proper winding of flax will require some skill, it is difficult to achieve an acceptable result the first time. To many, this method seems outdated, but some plumbers still use flax, due to its cheapness and availability.FUM Tape (Fluoroplastic Sealing Material)
This versatile and reliable sealing material has excellent thermal and chemical resistance. Suitable for both drinking water and chemically active liquids and gases. The FUM tape is convenient and does not get dirty in operation, however, it does not guarantee reliable sealing and does not protect against corrosion. It must be borne in mind that vibration loads often cause leakage of connections with the tape. It is also not recommended to seal large diameter joints with it. The use of this material will require professional experience, it is necessary to determine in advance the correct thickness of the winding and the degree of tension of the tape, because if a leak occurs, you will have to start work from the very beginning. Also note that the FUM tape is quickly consumed and has a fairly high price.Polymer threads
This sealant combines the advantages of FUM tape and linen, it is also hygienic, safe and convenient. Unlike linen, it is completely synthetic and immediately impregnated with a sealing compound. The thread does not decompose and reliably protects the connection from corrosion. And unlike the FUM tape, the connection assembled on the thread can be adjusted (adjusted) and it easily withstands vibration and other mechanical loads. All this is due to the structure of the material, which consists of many elementary filaments. However, when used in systems with harsh chemicals and some petroleum products, sealing integrity should be verified by running the system in test mode. Well-known brands on the market are Tangit and Loctite from Europe and from a Russian manufacturer. Threads are comparable in quality, but domestic ones are much more affordable.Anaerobic gels
The most technological and fast method sealing pipes today are anaerobic gels. These are liquid polymer compounds that begin to harden upon contact with metal in the absence of air. Gels have high adhesion (sticking to the surface) to metal and evenly fill the thread. This ensures reliable sealing, resistance of the connection to heavy loads, corrosion and temperature extremes. Polymerized gels are completely safe and non-toxic, suitable for any liquids and almost all gases. But, applying them, you should take into account some features. Before starting work, it is necessary to pre-prepare the thread, remove dirt and, if possible, degrease. In addition, since curing takes place in the absence of air, the composition may become unstable when used in a pure oxygen environment. At temperatures below +14°C, the polymerization time of the gels increases, but this is easily solved by tightening the connection with a wrench and warming it up. Also, heating may be necessary to dismantle the structure if a strong fixation gel was used or a joint with a narrow threaded gap was sealed. A rather high price justifies itself with durability, reliability, economical consumption, speed and ease of use of anaerobic gels. There are several types of anaerobes on the market, the most famous are Seseal and Loxeal from Europe, and StopMasterGel can also be noted from gels. Comparison of the main characteristics of seals you can see in the table:Options | linen strand | fum tape | Russian thread "Record" | Russian anaerobic SantekhMasterGel |
Price | 80-100 rubles / 100 gr. plus impregnation | 200 rubles / 50 linear meters m | 245 rubles / 50 linear meters m | 395 rub/60 gr |
Application technology | Complex. Experience Required | Complex. Experience Required | Simple. No experience required | Simple. No experience required |
Application conditions | Can't stand high pressure, requires impregnation, biodegradable | Weak vibration resistance. Impossibility of alignment | Universal sealing material. Suitable for most tasks. | It is necessary to prepare the thread - degrease, if necessary, remove dirt with a brush |
Resistance to aggressive environments | No | Yes | Yes | Yes |
Degree of vibration resistance | Medium | Low | high | high |
Thread cleanliness and quality | With restrictions | Demanding | unpretentious | Demanding |
Additional material preparation | Requires impregnating treatment | Ready to use | Ready to use | Ready to use |
Working temperature | up to +150ºC | up to +300ºC | -60 to +150ºC | -60 to +150ºC |
Connection life | Several months to 5 years | Up to 13 years old | Over 20 years | Over 20 years |
This review will help a novice plumber decide on a method for sealing pipes. The article contains a detailed analysis of all materials used for this purpose: flax, FUM tape, plumbing thread and various sealants.
It is much better to use silicone sealant instead of paint. When applied abundantly, it impregnates linen well, reducing its hygroscopicity, and also plays the role of a lubricant, facilitating assembly. The disadvantage of this method, as in the previous case, is low manufacturability and the need for additional components. However, it is an excellent choice for a locknut seal and for fitting items that need positioning (faucets, eccentrics, etc.) because the linen winder is adjustable and maintains a tight seal even if the connection is not fully tightened.
Fum
Fluoroplastic sealing material (FUM) is a military development. And although thin polymer tape has long and firmly taken root in the arsenal of plumbers, it was not created at all for use in plumbing and heating systems. Due to its chemical inertness and exceptional heat resistance (up to 300 °C), pipe sealing with FUM tape is used in pipelines with a chemically active, explosive and high-temperature internal environment, including pure oxygen.
The FUM tape protects the thread from corrosion, does not rot and does not dry out; it is technologically advanced and easy to use. The smooth surface of the belt reduces friction, which makes it easier to assemble and dismantle - part of the turns can be done by hand.
Unfortunately, it is the high antifriction performance that is both an advantage and a disadvantage: the connections on the FUM do not withstand vibration and mechanical loads. The second drawback is the depressurization after the thread reverses. For these reasons, repair and installation work on pipeline systems assembled entirely at the FUM becomes like a sapper: one careless movement and some of the connections will have to be rewound. In addition, in order for the sealing of pipes to be reliable, it is necessary to twist into the thread run or counter. The listed disadvantages make the FUM tape unsuitable for installation with positioning, especially taps and valves.
plumbing thread
Thread winding for water pipes is a dense cord made of thin synthetic fibers impregnated with a non-drying water-repellent composition. It has all the advantages of flax in combination with a sealant, but unlike it does not decompose, successfully resists chemical attack and better protects against corrosion.
The plumbing thread allows back-adjustment up to 180° (flax only up to 90°) and partial tightening, while maintaining the tightness and resistance of the connection to mechanical stress in all directions. In addition, this method is more technologically advanced and convenient: the winding is completely ready for use, which does not require unnecessary actions and the use of additional materials. Its only drawback can be considered a relatively high cost.
Plumbing sealants
General advantages of materials in this class are ease of use, corrosion prevention and lubrication. Silicone sealant is rarely used without combination with various types of fibrous materials, and non-drying compounds can be used in pure form only in non-pressure systems, otherwise they will simply be forced out of the thread. Drying sealants withstand pressure well, but with a large gap, they shrink significantly as they cure.
These shortcomings are deprived of an anaerobic sealant, which hardens without air access, but only upon contact with metal. Obviously, both conditions are met inside the threaded connection. At the same time, the volume of the sealant does not change - there is neither shrinkage nor swelling. The material has sufficient chemical and thermal resistance, and is also able to withstand no less pressure than the pipe itself. The gel is adhesive to the metal, which makes the connection rigid and durable, even when not fully tightened. On the open surface, the anaerobic sealant does not harden - the excess can simply be wiped off with a rag or washed off with water.
The main disadvantage of this material is some complexity of use: the thread must be clean and free of grease, and at temperatures below room temperature, the pipe will have to be heated in order for the gel to seize. Disassembling a connection without heating is also not always possible, especially if the diameter is more than an inch.
Conclusion
The least technological option of all considered is linen in any combination. And although impregnation with a sealant brings it closer in properties to a synthetic thread, it is seriously inferior to it in terms of service life, and the low price hardly compensates for this.
The remaining materials are technologically advanced and are approximately equal in terms of durability. The cheapest of them is FUM, but it also has the most disadvantages. Against this background, sealing pipes with plumbing thread looks preferable, despite the relatively high price.
In turn, it is inferior to anaerobic sealant in terms of reliability: its use requires a certain skill, without which it is impossible to guarantee complete tightness. However, skill is a gain, and plumbing thread is easier to use, and it costs less.
Non-drying silicone sealants are best used as an impregnation for flax. Drying pastes and anaerobic gels are quite self-sufficient, but the former demonstrate low reliability with a large thread gap, and the latter are the most expensive material of all. Nevertheless, their price is adequate to the quality, and in most important indicators, these materials are superior to all others.
Thus, the most versatile, technologically advanced and reliable seals are plumbing thread and anaerobic sealants. Their use reduces the assembly time, increases the reliability of the system under any operating conditions, which fully pays for their cost.
Andrey Kazantsev, rmnt.ru
On sale you can find many different materials that are designed to seal the joints of pipelines. The question arises - which of the materials in which cases should be used? And also, - how to use this or that sealant correctly?
It is often possible to apply two or more thread seals at once, then clarification is required - what to prefer. The recommendations given should help to understand these issues and find a solution that will ensure sufficient reliability of the connection of pipes and fittings on the thread for the entire period of operation.
Linen winder
Flax is a cheap material for threaded joints, creating a very high quality seal. The only thing is that it can not be applied in all cases.It is designed for joining metal parts, as it creates a significant density. It is very durable, the efforts applied by the keys to the two parts to be connected require significant.
Therefore, flax is not compacted:
- plastic parts - the tightening torque exceeds the strength of the material, the parts will be crushed, destroyed, at least the thread.
- parts in which a metal sleeve with a thread is embedded in a plastic (polypropylene) shell, due to the risk of rotation (disconnection).
Linen "dry" is not used, it must be lubricated with a special sanitary paste. It is applied either directly to the thread or to wound flax.
Popular experience also suggests that sunflower oil can be used instead of pasta, while the quality of docking does not decrease, at least there is no such information.
A strand is separated from the linen and wound along the thread in each stream. Winding is done tightly and neatly. There should be no protruding hairs. The first two turns are not filled, and a shoulder is made at the end of the thread.
Special plumbing thread
A special thread for seals, high strength (cannot be torn by hand) wound on spools, sold in stores. Its main drawback is its high price, otherwise it has solid advantages.- It can be used on any parts, the tightening torque is less compared to flax, so plastic can also be wound.
- It seals very well and can be used even on torn threads.
Winding is carried out in the same way as with flax - the first two turns of the thread remain empty so that the parts can be joined, and then winding is carried out along each thread stream, at the end of the winding - a double layer, i.e. shoulder.
fum tape
Fum tape is not very suitable for creating reliable connections on pipelines. The material is not very strong, there is no sufficient density in the threaded connection of metal products with it. But for plastic connections that will be dismantled, for example, a summer irrigation pipeline, fum-tape is the most suitable sealant.With fum tape, the parts to be joined can be wrapped by hand. In this case, a small density of the joint along the thread occurs, so that no leaks occur for some time. A slight twisting force does not provide sufficient tightness, does not guarantee that this joint will not leak. For fixed connections, especially if they are inaccessible during operation, it is recommended to use other materials.
If there is a rotation of the connection with the fum-tape, which is already in operation, then most likely there will be a leak. This is a serious drawback, given that rotation does not require much effort.
At the household level, fum tape can be used (and is popular due to its cheapness, ease of use, and low effort) for connections that are in plain sight - when connecting showers, faucets, etc.
Plumbing adhesive sealant for threaded connections
The material is special, not quite cheap, it seals well, there are no cases of leakage after its correct use. But only after the wrong….The obvious disadvantage of sealant glue is that the quality of the joint will depend on the "human factor" more than with windings. The fact is that glue does not work normally on greasy surfaces.
Where will greasy surfaces come from? It may just be carelessness - they dropped oil on the thread or rubbed the part in oil with their hands. Parts can be stored in a lubricated state (primarily for steel). But the main thing is that lubricant is used when threading. After such an operation on steel parts, adhesive sealant is completely unsuitable.
It should be noted that there are glue samples with which the undocking of pipes requires heating over 100 degrees. Such heating is often difficult, not safe, plastic can be damaged, etc. Therefore, the adhesive-sealant is still selected according to the circumstances.
The glue is easy to apply. It is applied only immediately before joining, squeezed out of the tube onto the thread and smeared with a finger over the entire thread without gaps.
In what cases should glue be preferred?
- When connecting plastic parts to metal, glue will be preferable. But such a connection is not common.
Winding features
Thread winding requires great accuracy of execution. The thread must be filled with an even layer without gaps, there must be a sealing material in each stream. It is laid to the end of the thread, where a shoulder is formed from it.
The main seal of threaded connections occurs on the last two threads. On the details, more often, the last two turns of the thread are not cut to the full depth. Therefore, in this place the material is wedged between the two parts very tightly.It is not bad if, during the performance of work, additional (cross) quality control of the winding with flax is organized. This is especially true when several dozens of such connections are performed at once.
conclusions
- For those who are constantly engaged in installation, it is recommended to always have flax, plumbing thread and adhesive sealant with you in order to quickly and efficiently complete any connection. It is recommended to apply all this in accordance with the tips above.
- When doing work at home with your own hands, when something simple and visible is being done, you can use a cheap fum tape, but you need to wind more. When installing entire systems with your own hands, it is better to use linen (with vegetable oil) on metal, and for small amounts of work it is even better to use a thread. Maximum attention should be paid to the quality of winding on the thread.
What should never be used to seal threaded connections:
- It is not necessary to use plain silicone, it is intended for flange connections.
- No need to use paints, whitewash, red lead, which give a little sense, but make the connections semi-collapsible - this is long outdated.
Also read more
I talked about how I drain water from boilers. Today I would like to talk about threaded connections.
Who is this article for?
Having already written the article, I thought - for whom is it? First of all, of course, for me, because when I wrote it, I got a fair amount of pleasure. Secondly, I think, for people who are not professionals and are "afraid to start". Well, if professionals read it and they like it, then I will not even be happy, but just happy.
Well, before starting
Let me remind you that I am not a professional, that is, self-taught, I did not study anywhere in my specialty. But I have a lot of experience.
Unfortunately, or maybe fortunately, no one has yet canceled the threaded connections in our water supply system. Personally, at first it was not very pleasant for me, since these same threaded connections took me a lot of time and I could not test each for reliability in advance. That is, before letting water in, you must first collect everything, then check which connections are flowing, then disassemble and fix everything (!!!). Now I don't care, because I somehow learned to feel "by touch" whether the connection will flow or not. Rather, not even "to the touch", but in the process of twisting. But maybe we'll talk about that a bit later.
What can be used to seal threaded connections
Sealing tape
For modern plumbers, several modern options plumbing thread seals. There is a special tape and there is a plumbing thread. I'll be honest. I do not like the tape at all, that is, absolutely. I tried it, but with it I had the most "spans". In addition, it is consumed faster than other materials. And in combination with a rather serious price, it is in the last place of my rating of materials for sealing threads. I suspect that it will take at least half a package of such tape to connect an inch threaded connection, which is completely unacceptable.
Sealing thread
plumbing thread
plumbing thread
A thread like "Tangit" is generally not bad. But it is also very expensive and it is also quickly consumed. But if the task is to use exclusively modern methods, then it fits better than tape. I wanted to switch to using it, but I kept pulling. And somehow recently I had to call a plumber to install a water meter in my apartment in Moscow. The guy turned out to be quite young and professionally savvy. I talked to him on a professional topic and, among other things, asked, of course, what kind of sealant he uses. He looked at me so sympathetically and said, "Of course, flax! And what could be better?" And if before that I doubted what to use, then after this conversation I somehow stopped doubting. Moreover, I used flax all my life and was very pleased with it.
Plumbing flax
Braid sample of fairly good quality sanitary flax
Flax has been used for sealing threaded joints from time immemorial. A good, thick braid made of very high-quality sanitary flax costs only 20 rubles and has an unforgettable smell. I really like it, although at first it is a little shocking and makes you think about who had this braid cut off ... And is there any deception here, because the braid of sanitary flax smells, sorry, not of flax, but of a goat.
Linen is good because I can twist a thread of exactly the thickness that I need from it. That is, if I connect inch pipes, then I do not wind kilometers of tape on the thread, but simply weave a thread of the required thickness from flax and wind only one layer.
If I need to make a temporary connection, for example, screw on a plug, then linen completely allows me to work "dry". Moreover, the quality of the connection either does not suffer at all, if the thickness of the thread is chosen successfully, or suffers quite a bit, and this does not interfere with work, that is, water does not pass through it. I'm going to talk about aspects of connection quality later.
The relative minus of flax can be considered the fact that the winding of flax on the thread, in turn, also needs to be compacted. But the minus is relative. About him a little later, because it was about the compaction of flax that I wanted to write. So everything that you are still reading up to now is only an introduction to the main topic.
Exotic thread sealing methods
Do you know how threads are sealed on products such as ready-to-use plumbing pumping station? Definitely not flax. And I doubt very much that it is tape or thread. I believe that all the described methods are not suitable for production, since they involve manual labor. I don’t have a very good idea of a machine that would seal a threaded connection in a way that is generally accepted for us ( ordinary people) method.
So how are threads sealed in production? I don't know for sure, but I suspect some kind of glue. And it would be very, very interesting to know. And basically I would like to know if this glue can be bought in a store? And if possible, in what way? I have never seen anything like it on any counter in my life, although, of course, I was interested.
And since the question of glue remains open, the tape has more disadvantages than advantages, the thread is terribly expensive and this is also not its only drawback, you have to use flax, in which the balance between advantages and disadvantages is quite decent and outweighs more in the direction of advantages. Moreover! I suggest novice plumbers not to suffer and choose flax for work. Do not worry! It is modern, reliable and very honorable. Let me remind you that I myself was worried about this, but a professional plumber very successfully reassured me on this subject.
Thread sealing principle when using different sealing materials
I would like to "load" readers with a fair portion of information about the principle of sealing threads in water connections. I am sure that many do not even suspect that each material has its own sealing principle, that is, it is completely different from others.
Notice! I am not writing a textbook here, but I am reporting my observations to you. If you think otherwise, please comment. Registration is not required for this.
Tape sealing principle
We wind the tape on the thread. We make it tight. The denser the better. But if the tape is pulled hard, it stretches (another drawback). Since the tape itself is soft and, it seems to me, that it also melts when the thread is tightened, the tapes must be wound not a little, but not too much. Unfortunately, when we start to twist our parts, the sharp ends of the thread cut the tape into a rather thin noodle. Care must be taken to ensure that all the noodles remain in the thread grooves and seal them properly. No lubrication is needed for the belt. It is slippery in itself and when twisting, I usually cannot determine how well (tight or not) the thread is connected, that is, the connection is twisted as if there is no seal, or there is too little of it. This circumstance also does not at all contribute to my sympathy for the tape.
Attention!
The principle described above may not be the only one and not the most correct one possible. Look at the comments. There is a tape lover's opinion. The reader tells us how to use it correctly and economically.
Thread compaction principle
When compacting with a thread, the principle of use is fundamentally different from other materials. We do not wind it into grooves. It is wound across the thread. The instructions for the thread say so - "Make sure that the thread does not fall into the grooves." The thread is thin, very strong, and coated with a material that makes it look a bit like ribbon. I think it's polystyrene or something like that. When twisting parts, the thread does not break with a thread (it should not break), because it is very thin and, as it were, lubricated. Moreover, the fact that the thread lies across the grooves does not allow it to unwind, and, very importantly, to spin in the thread. What do I understand by this? The fact that if the thread lies in the grooves, then when we wind anything on our pipe, say a coupling, the thread will spin along the pipe thread together with the coupling and will not seal the thread, but will come out from under it. As a result, we will get a not very reliable connection, since it is quite possible that only one or two threads will be sealed. And the rest of the thread will simply unscrew from the thread in the course of winding the coupling.
Of course, winding the thread across the threads of the thread is a kind of breakthrough. But in the same way, this imposes on the plumber a certain duty to ensure that the winding is very uniform. If the thread will often lie on the thread (on past turns), it will give too thick a seal, which will either be cut when winding, or wrinkled, and then the result is generally undefined. It can be said for sure that the ability to wind the thread across the grooves is the MAIN difference between the thread and other sealing options.
Adhesive sealing of threads
I believe that it has practically no flaws. There is only one question. Do such adhesives actually exist, and if so, what is the technology for their use. It seems very likely to me that these could be hot melt adhesives, that is, they soften at a certain temperature. Again, adhesive threads are the realm of fantasy, since I have never seen such adhesives. Well, in general, there are questions about the environmental friendliness of such glue.
No fantasy!
For first-hand information, namely from professionals who have dealt with sealants and adhesives, see the comments.
Linen seal.
When compacting with flax, we twist a thread of the required thickness and wind it into the grooves of the thread. Of course, flax can unscrew along the thread according to the process that I described when I talked about the thread. In order to prevent this from happening, we need to lubricate the surface of the flax so that the coupling (for example) is screwed onto our threads stronger (tighter). Then the friction between the flax and the pipe will be greater than the friction between the flax and the coupling. This will allow the sleeve to firmly seal the flax into the thread grooves. It is this approach that ensures the primacy of flax when used by professional plumbers. But you need to choose the material for lubrication well and correctly.
My personal take
You know, when I learned to combine water pipes, could not find a normal printed manual. He acted exclusively by "poke". It was hard but not too hard. I very quickly found a way to wind flax on a pipe, which I use now. It is likely that it is in general use, because it lies on the surface. Here's how I do it.
- First, I weave a thread from linen, which corresponds in thickness to the thread. There is no guide here. Purely by eye. Obviously, the thread should not fill the entire thread. Then there will be no room for the counterpart of the thread on the part that we will wind.
- Then I wind the linen around the pipe, but not from the end, but vice versa, from the beginning of the thread to the end of the pipe. With the first turn, I try to firmly fix the tip of the linen thread on the very first thread of the thread. But having fixed and properly tightened the first loop, I begin to wind the remaining thread. I wind in the same direction in which the coupling will be wound onto the pipe. It is quite obvious that with this method of winding in one place there will be a transition of the flax thread through the thread of the thread. But it will be only one for each revolution and does not interfere. It is only necessary to carefully monitor that the winding is more or less accurate and there are not very many jumps over the thread. Otherwise, the clutch may cut the flax when winding it up, crush it and push all the flax out. In practice, this is not easy to do. It takes some practice and no rush.
That's all. Then you need to cut off the excess flax, lubricate it and start winding the clutch.
Note!
I bypassed the breakthrough that was introduced by the thread. I also have flax jumps over the thread. And in the amount of exactly one per turn. Thus, the thread does not have a single advantage that it (the thread) can be proud of.
Flax lubricant for sealing threaded connections
Oil paint
But I saw references to lubrication in books. In the books of the Soviet era, it was proposed to compact (lubricate) flax with oil paint. And old plumbers successfully use this method. Oil paint, of course, is something. She first lubricates, and then glues the connection almost tightly. I encountered one of these. I dismantled one heating and cursed everything in the world. Almost every connection I had to heat almost to red. Only then could I unlock it. I note that not everywhere you can just use a hair dryer or a burner like that. There are all sorts of factors, such as wallpaper on the walls, that you don’t want to burn. But it has to.
Silicone sealant
Personally, after I encountered oil paint, I realized that I would not use it. I decided to use silicone sealant. I have personally used it myself in my house for both heating and plumbing. And I liked it. Sealant perfectly lubricates flax. After winding the coupling (for example), some amount of sealant is squeezed out and it can be neatly and even beautifully wrapped around the connection (more precisely, along the rim, which is formed by the connected parts). And finally, the sealant has the ability to dry out, which is also very, very nice.
Already after I used this sealant, I read a warning that silicone sealant should not be used in threaded connections. That the sealant is an acid that corrodes the thread completely.
I gladly report. This is nonsense! As mentioned in the announcement of the cycle, I changed the plumbing, assembled on silicone 10 years ago. When examining the threads with a magnifying glass, I did not find any (!!!) traces of the sealant on the thread. What's more, the threads under the sealant retained their virgin luster! Another thing is that it was not easy to tear off the flax with the sealant from the thread! But even here I very quickly found a way. I cleaned the threads with a dense metal brush. As I said, the threads under the sealant unwinded well and remained virgin, which allowed me to reuse many non-ferrous metal parts.
The next two pictures illustrate the above, namely that the silicone sealant not only ruined the thread, but, on the contrary, made it better. Even the section of the pipe that was exposed to air was worse preserved than the thread under the sealant (in the case of a galvanized pipe).
Modern materials for sealing (lubricating) flax
Remember I told you about my conversation with a professional? So it was he who told and showed me a tube of a special ointment for sealing threaded joints. I bought one and tried it out. I'll be honest. This is something amazing. The effect is simply amazing. I have now forgotten about silicone sealant forever and have no idea how I used to live and work.
Modern agent for lubricating and sealing flax in threads
Briefly speaking! This ointment is extremely oily. She is non-drying. Its main advantage is that now I can practically not worry about the amount of flax in the thread. That is, now I can twist the thread a little thicker and wind it around the thread a little less carefully. In some way, incomprehensible to me, all the linen is crushed and falls into the carving without much effort on my part. I made some connections. Linen seems to become part of the carving. The probability of messing up the connection has globally decreased. Well, the best part is that at a significant price of a tube, the consumption of ointment is more than modest.
It was almost impossible to remove the used thread from the thread without the help of a metal brush.
The hyped connection (the one that was made in the movie)
Please note that all the threads lie completely in the grooves in which they are needed. As I said, flax has practically grown into the carving. This means the connection was exceptionally reliable.
I guess we owe this effect entirely to the super sealant from the tube.
Bad screw connection
But, on the contrary, an unsuccessful connection. It was made "on silicone sealant". Pay attention to the fact that flax went for a couple of turns and then began to wrinkle like an accordion. Nevertheless, the connection stood for 10 years and would have stood for no one knows how long. Probably eternity. And we fixed the quality only when we untwisted the connection.
How tightly should the plumbing parts be screwed on?
Here is a very good question. Do I need to wind one part onto another and still pull it up? According to textbooks, yes. From experience this is not always possible. It happens that a completely wound and tightened corner looks completely in the wrong direction. I'm not worried and just unscrew the corner so that it looks where it needs to. And this connection has never let me down. In short, I will continue to continue to "cheat" in this way. And as you wish.
OK it's all over Now. If someone liked this material - I will be just happy. If you don't like it, then I'm sorry!
Master of long descriptions of short processes
Dmitry Belkin
Article created 08.10.2013
Article edited 01/11/2014
Friends! When you write comments, indicate whether you are a professional or an amateur. A professional is a person who works as a plumber for 8 hours every day. And all the rest are amateurs (conditionally). If you have 100 acquaintances and you fix plumbing for them and work in an office, then you are an amateur. Deal?
Thank you so much for the detailed and well presented information. I'll link to it in the article now.
Mercy, Eldar, for the high appraisal of the project! You and I seem to be doing the same thing. But I never use anything other than linen. It happens that I wind flax dry.
Just yesterday I had to change the current connection in the heating. It was collected on Fuma and flowed after 5 years of service.
Well, I thought about solidol. But there were questions about its composition and the safety of all components. For example, machine oil is extremely unhealthy.
My experience is that tape, in any condition, even insulating blue or black, is especially endearing to amateur plumbers. Personally, I do not really understand such love, but I treat other people's tastes with understanding and respect. Ultimately, only two things are important - that it does not flow, and that it is comfortable and pleasant to work.
This is probably a plus.
I'll tell a story! When I was young and inexperienced, and I was training on my own pipes, there was a time when I put everything together and one connection leaked. But not so much, but so ... one drop per hour. I was too lazy to change it and I put it off the next day. And the next day I decided to take everything apart, and the connection is dry. But where it flowed, a lot of hardness salts accumulated. And I thought that it was hardness salts that additionally sealed the joint. But now I think that it is possible that the flax is swollen. But I still redid this connection.
One more thing. When the leak is stronger than "a drop per hour", it does not tighten itself. I also had such cases.
Let's say that you are the owner of a cool car that automatically brakes when the sensors indicate that it is about to crash into the car in front.
Will you stop using the brakes? Will you specially accelerate to check the automation? Personally, I don't.
Thank you for your kind review and detailed comment.
Dear Yaroslav!
I am reporting to you my personal experience.
It is not so important dry flax or oiled. Either way, it shouldn't leak. Winding linen dry is not such a rare occurrence in fact.
I admit that linen can get wet and swell, but in my practice this has not happened. Well, it happened a couple of times that it dripped a couple of times, and then everything was dry, but it was somehow very unsteady and doubtful. Much more often it happened that the connection was dripping for years. Moreover, if the dripping compound is a simple iron one, then it will definitely rot in the place of the drop. Copper can flow forever. It will simply be green (copper oxides) or white (hardness salts from water).
Is there a possibility of a leak in the future? I do not know, but I think that if it drips, then it will drip until it rots. In my practice, a dripping connection has never broken through. But even for years, I usually don’t drip anything. Only if I didn't notice somewhere. Of course, if you increase the pressure in the system, then it will drip more.
If the connection is not dry, or not completely dry, then it is better to redo it. And if it's dry, then I wouldn't worry.
Dear Sergey! Thank you for your opinion in favor of the FUM tape!
Obviously the author (I, that is) expresses my personal thoughts and preferences here on the site. And all the commentators also only express personal ones. Yes, and you, too, it seems to me, expressed your personal ones. And I am sure that readers of this material will take them into account! For example, your approach to tightening couplings under pressure is new to me.
Your experience is very close to mine.
By the way, a little observation from life. Reworked some of my heating (ready for winter) and used brass parts from a local store. The parts are nice to look at but cheap. I suspect Chinese. 3/4 inch. And now, imagine, the threads turned out to be some kind of particularly deep, or something ... I had to twist the thread much thicker than usual, so that the parts were connected with some more or less tightness. Of course, I connected everything successfully, but I had to redo it 2 times, each time twisting an increasingly thick thread. Otherwise, the parts twisted too (suspiciously) easily.
Hello for you too! Thanks for the comment.
I also had such strange connections in practice. Here they drip and drip. I even looked through a magnifying glass and didn't see anything.