Old and bulky cast iron pipelines can still be found in many apartments. But no matter how reliable they may seem, sooner or later their service life comes to an end. Great solution may become complete replacement cast iron to plastic, but, unfortunately, this is not always possible.

Stops someone financial side issue, others fail to come to an agreement with their neighbors. It is in such situations that the need arises to connect plastic and cast iron sewer sections. There are several methods that allow you to carry out such work quickly, efficiently, and without the involvement of professional help.

The entire complex of work can be divided into four stages:

1. Preparing the work site and the necessary tools.
2. Dismantling of the old pipeline.
3. Installation of plastic pipes.
4. Connection of elements.

To make the connection between a plastic pipeline and a cast iron pipeline reliable and durable, you should prepare everything in advance necessary tools and materials:

• A special hammer with a rubber or wooden head. An ordinary iron hammer will not work here, since it can easily damage cast iron, which is so durable in appearance but very sensitive to impacts.
• Cutting tool. This could be a grinder or a hacksaw.
• Adjustable wrenches.
• Depending on the selected connection method, you may need hand press, thread cutter or welding machine.
• Plastic pipes of suitable size. To connect the toilet to the riser, you will need elements with a diameter of 110 mm; for laying pipes to the bathtub and sink, plastic with a diameter of 50 mm is best suited.
• Necessary adapters, gaskets, couplings, seals, sealing agents.

Pay attention! Installation of a plastic pipeline must include inspection hatches. Neglecting this rule will significantly complicate renovation work, if there is a need to carry them out.

Dismantling an old pipe

The cast iron pipeline must be dismantled very carefully to prevent chips or cracks.

Hello, dear reader! In many houses and apartments, cast iron pipes are often adjacent to the water supply and. Therefore, situations arise in which the home master is faced with the question: how to connect a cast iron pipe to a plastic sewer?

In this article we will look at the methods of this connection, step by step operations and advice from practitioners.

The need for such a procedure arises in the following cases:

• replacement of cast iron elements of the sewer main with more modern smooth plastic pipes;
• making new wiring from polymer pipes for pressure sewerage;
• laying a plastic pipeline from the home sewerage system to the septic tank;
• emergency breakdown of a tee or socket made of cast iron;

Connection methods

The choice of connection technology must be based on the integrity of the cast iron socket. Either it is intact and suitable for further use, or it has burst, damaged, or cut off.

Connection with fittings

The use of the fitting looks like the best solution from the point of view of ensuring a reliable connection.

A press fitting is a polymer adapter, at one end of which there is a thread, at the other - a socket extension for a joint with a PVC pipe.

Scheme for installing a press fitting on cast iron:

The method is used in cases where the cast iron pipe does not have a socket at the end, or it cannot be used. The reliability of the connection is ensured by the tightness of the thread and rubber seal fitting.

• At the end of the cast iron pipe, 5.5 threaded turns are cut with a die.
• Wrap the FUM tape, you can use plumbing paste, and screw the fitting.
• A plastic pipe is inserted into the fitting collar at the other end.

Connection with rubber gaskets

Rubber seals are suitable when the bell is safe and sound, thoroughly cleaned, and there is not a single bump on its inner walls. Otherwise, leakage cannot be avoided.

The rubber cuff must be selected according to size.

1. The inner walls of the cast iron socket and the outer turns of the rubber adapter.
2. The seal is carefully and tightly installed in the socket.
3. The plastic tube is inserted into the socket through the cuff at least 5 cm, or deeper.
4. The joints are once again coated with a sealant composition.

This connection is quite reliable and easy to disassemble.

If you have to make a joint with a pipe without a cross, use a polymer adapter with a rubber cuff.

1. The end of the cast iron element is leveled by cutting with a grinder.
2. A rubber ring and seal are placed on it. All this is lubricated with sealant.
3. A plastic adapter, also treated with a sealing compound, is placed over the edge of the pipe.
4. A plastic pipe of the appropriate size is connected to it.

Silicone sealing

This method is the easiest and widely applicable at home. It is suitable if you simply need to cover up the gap that has formed between the walls of the socket and the plastic. In this case, the gap should not exceed two mm.

1. The bell is cleaned and dried with a hair dryer.
2. A special plumbing thread is wound around the end of the plastic pipe, which is a kind of sealant made of polyamide thread and silicone coating.
3. The pipe is inserted into the socket and the cracks around it are filled with silicone. The silicone should go as deep as possible in the socket, to the very end of the plastic pipe.
4. The drying time of silicone sealant is about 5 hours.

Socket connection

The most popular, which has become a classic, method of connecting a cast iron pipe through a socket is caulking with flax and cement.

Since cracks almost always form in the socket during a joint, so-called caulking is used.

1. A plastic pipe is inserted into the cleaned socket until it stops, the end of which is wrapped with linen rope. The winding is coated with plumbing paste.
2. Using a simple screwdriver, push and seal the winding into the crack. The sealant tightly fills two-thirds of the joint space.
3. Then apply cement mortar, add PVA glue to it, and inject it into the joint until the gap is completely closed.
4. The mixture will completely harden only after a day, so using the pipeline at this time is not recommended.

With the advent of silicone, cement mortar is often replaced silicone sealant.

It is believed that this method is unreliable: the coinage deforms plastic part, moreover, under the influence hot water plastic and cast iron expand with different forces and the cement joint will quickly become loose.

Flange connection

The flange is used for joining pipes with a large diameter. It is difficult to use threaded fittings here, but the connection with flanges is strong and reliable. The connection can be easily disassembled if repairs or cleaning are necessary.

To complete the connection, welding work will be required.

Today there is a wide variety of flanges on the market that allow the transition from cast iron to plastic.

Step-by-step connection instructions

Let's take a closer look at the work on flange connections with your own hands. First of all, you need to prepare for the operation: decide on the sizes and types of flanges, materials, and select a tool.

Set of tools and materials

To dismantle a cast iron pipeline element you will need:

• a mallet with a rubber attachment (with a regular hammer you can easily split brittle cast iron);
• grinder for cutting cast iron pipe parts.

To install the structure you need:

• welding machine;
• plastic pipe cutter;
• plastic pipes;
• flange;
• appropriate seal;
• for cleaning the end of a cast iron pipe - a file or a cleaning disc for an angle grinder;
• a screwdriver with bolt bits or socket wrenches of a suitable size.

Work progress

1. Using a grinder, cut off the end of the pipe to the required size.
2. Clean it from nicks with a file or a special disk using a grinder.
3. A flange is welded to the end of the cast iron pipeline.
4. The crimp sleeve is placed on plastic part structure, and its flanged part is bolted to the flange of the cast iron pipe. A sealing gasket (ring) is placed between them.

Connection video

Flange connection video

To insert into sewer pipe When switching from cast iron to plastic, a fitting such as a compensating pipe can be successfully used. It is able to compensate for deformation and failure of the network due to its linear temperature contraction/expansion. In addition, it can give the desired slope to sewer sections.

The pipe is used along with the corrugation when it is necessary to change the height of the cross in order to create the optimal angle for installing the toilet.

Nuances

The pipeline is always routed from the riser.

Remember that cast iron and polymer have different coefficients of thermal expansion. Therefore, it is important to use plastic materials such as silicone for sealing.

When using threaded connection, be sure to wrap tow around the threads and lubricate it with plumbing paste.

It is always necessary to start assembly from the riser

Is it necessary to dismantle the old pipe?

If we are talking about a cast iron sewer riser in apartment building, then, firstly, this should be done by specialists invited by the management company, and secondly, this operation in a separate apartment is very undesirable. As practice shows, it is better to replace the entire riser throughout the entire entrance during a major overhaul.

Hello! Today I will tell you how to make the transition from a cast iron pipe to a plastic one.

This article will help you independently hammer out a cast iron sewer for repair. After which it will be possible to install a plastic pipe into the cast iron socket.

What are the difficulties in this task:

1. According to the diameter standard, a cast iron pipe is larger than a plastic one.
2. It is impossible to disassemble the connection without knowing the hardware. The joints look like a single whole.
3. A cast iron pipe breaks easily; you must work extremely carefully with a hammer.
4. The cast iron socket is caulked with sulfur or cement. With different coinages - different way dismantling.
5. When minting sulfur, you will need a torch and a gas mask.

Diameter standards

Let's look at the situation using the example of a cast iron sewer tee to a bathroom. node

The fact is that it is this tee that is most often changed during repairs, even if it is in working order. It takes a lot more space than plastic. And this is important, since with a plastic tee the toilet can be installed closer to the wall and further from the door. Well, that is, while sitting on the toilet you can read an encyclopedia.

Tool

The minimum we need:

1. Plastic cuff
2. Sealant
3. Lubrication
4. Hammer
5. Flat head screwdriver
6. In case of sulfur, burner and gas mask

Step 1. Chasing

The method of caulking a cast iron pipe depends on how it is assembled:

1. for cement
2. or "sulphur"

1. Cement

You need to take a small chisel or flat-head screwdriver and gradually, slowly, knock out a small piece of cement. We place the screwdriver in the space between the pipe and the socket. We beat in a circle.

Under the cement there is a heel. A heel is a strand of flax impregnated with oil, which prevents the flax from rotting. We pick out the heel as much as possible.

After this we try to move the pipe. In the case of a tee, it is quite simple to move it: we insert some kind of lever into the outlet of the tee: a block or a long key. If the tee still does not move, then knock out the cement further. Don't use a big lever to force it off. There is a high probability of breaking the socket into which they were going to install a new pipe. Be careful. The work is painstaking and cannot be rushed.

2. Sulfur

Warning: fire. To begin with, it is necessary to ensure complete fire safety. You will be working with an open flame, remove anything around that could catch fire. Have water ready in case you do set something on fire. Air. Ensure the room is fully ventilated. Whether it’s winter or the heat of summer, open the window and door so that there is a draft. Otherwise there will be nothing to breathe. I recommend wearing a gas mask or at least a carbon respirator.

I assume that you can heat the bell with a hair dryer. The melting point of sulfur is approximately 450 °C.

After ventilation has been ensured and fire safety, turn on the burner and begin to heat the bell evenly. I highly recommend not putting the burner in one place and leaving. If heated unevenly, the cast iron socket may burst. At least I try to avoid such experiments.

It is not necessary to wait for the sulfur to flow out. It is enough to simply soften it with heat. Insert the lever into the tee elbow and move the tee. As soon as it moves, turn off the burner and, shaking it back and forth, move it to the side.

In the case of cement caulking, the same thing: as soon as the tee moves, start loosening it.

Before finally removing the tee, Immediately prepare a rag or other plug for the pipe. They can drain water from above, and there’s no point in breathing in the smell of sewerage.

Step 2. Clean and install the cuff

After we have hammered out the cast iron pipe and removed old site, you need to take care of the cleanliness of the bell.

We clean and wipe it dry so that no lumps remain.

Then we coat the cast iron socket with sealant and insert the cuff (sealant is not always needed).

I throw the cuffs into hot water for about 30 seconds. They become soft and easier to place!

I shared vitalix1974, in the comments on YouTube

Apply lubricant to the inside of the cuff.

Step 3. Insert the plastic pipe

And now all that remains is to insert the plastic pipe into the cuff.

It happens that the pipe does not want to pass into the cuff,

in this case, you can lightly tap the plastic socket to force the pipe into our cuff. Use a board or plywood to distribute the load by tapping with a hammer. Do not tap directly on the plastic pipe. It can be broken that way.

Good luck with your transitions!

In recent decades, the monopoly of old cast iron pipes, installed almost everywhere in old sewer systems, has been noticeably squeezed out by modern plastic analogues.

And we must admit: plastic pipes and fittings have already shown themselves to be excellent in practice - they are durable and have good permeability (if anyone doubts). In any case, if you still use cast iron pipes in your old house or apartment, you should be prepared that sooner or later you will have to replace them with plastic ones. And if there is no talk of completely replacing cast iron yet (it’s not so easy to change an entire riser in a high-rise building), then anyone can easily connect the pipes together with a reliable joint. And this is not so difficult, in principle anyone can do it, but you still need to know the nuances in order to do it correctly.

As a matter of fact, it is precisely these very nuances of how to connect a plastic sewer pipe with a cast iron one, well known to experienced specialists, that usually constitute main problem for beginners.

So, if you are interested in this issue, most likely you have a cast iron riser or some other piece of pipe that needs to be properly connected to a plastic one.

The quality of the connection must be such as to eliminate the risk of leakage at the joint. Considering that it is usually advisable to complete such work in one day, it becomes clear that one must be well prepared for this “operation.”

Important: When removing old cast iron pipes, do not forget that they are extremely fragile. Do not use a regular metal hammer for this work, use a rubber or wooden one. In former times, joints on sockets cast iron products usually sealed with cement mortar or with rags, having previously soaked them with paint. Admittedly, such a connection is quite strong, so carefully pull the pipe out of the socket, gently turning it from side to side.

What to do if the bell is damaged? You can't leave him in this state. Using a grinder, you need to carefully cut off the section of pipe up to the socket. Then the junction of the plastic pipe with the cast iron one can be joined more efficiently. Clean the cut piece of pipe thoroughly, removing dirt and rust, only then can you begin the joining process itself. You can cut metal with a hacksaw, but it will be tedious and time-consuming.

Important: Do not break off the sawn section of the cast iron pipe. Due to the fragility of the material, the product will almost certainly break somewhere nearby, and you will need to cut it again.

Methods for connecting a cast iron pipe to a plastic one

In cases where the old cast iron pipe must be removed, and inner surface the bell of the remaining pipe is smooth, you can get by in a simple way connections using any of the special plumbing seals.

Simple docking can be done in three ways:

• using a rubber gasket. The plastic pipe is inserted into the cast iron pipe by 3-8 8 cm. The connection can be made quickly and immediately after this the sewer system is in operation. This connection will normally last up to 6-8 years.
• caulk with linen wrap. This method is traditionally used for joining cast iron pipes, but it is also good for mixed joining. 1) in the area of ​​the joint, layers of plumbing winding are wound onto the plastic pipe. 2) the winding is pushed into the gap between the pipes with a spatula or screwdriver (this is called chasing); 3) it is good to treat the transition to a cast iron pipe with a solution of water, cement and PVA glue. It is not advisable to use the sewer for at least a day.
• seal with silicone. The method is good when there is a small gap (up to 2 mm) at the junction of the pipes. When carrying out work, pay attention to the tightness of the joint below. 1) thoroughly dry the joint; a hair dryer will help speed things up; 2) silicone is driven into the gap between the pipes with a construction gun, and the deeper, the more reliable. 3) the silicone must be allowed to dry, this is at least 3-5 hours.

At creative approach these options can be combined. If the gap between the pipes is large, rubber gaskets are used along with caulking. In the case of connecting the toilet with a “bayan” (corrugated pipe), caulking is used with a linen winding, covering the joint with sanitary silicone. It is also used to coat cast iron crosspieces and rubber seals.

It is important to understand that the junction of a cast iron pipe with a plastic one will serve reliably only if it is not subjected to various types of mechanical stress and temperature changes during the installation process. After all, this is what it is main reason leakage – the tightness is broken due to the fact that cast iron and plastic have different coefficients of thermal expansion.

If we are talking about sewer pipes through which hot water flows do not pass, this condition is not difficult to comply with.

It happens that apartment owners do not resort to adapters at all - a plastic pipe is simply inserted into a cast-iron socket sealed with cement. As a result of this, it is deformed, and the cement from the hot water is full of cracks. So the joint loses its tightness.

Advice: in extreme situations, you can seal the junction of plastic and cast iron pipes with porous rubber, carefully wrapping it around the plastic pipe, and then drowning the remains in the socket.

In practice, the connection of cast iron pipes and plastic ones can be done in several ways, depending on whether the cast iron pipe has a socket or not. If there is a socket, even an untrained person can make the joint. If the bell is missing or damaged, you will have to show skill and tinker. Fitting connections are used successfully. To do this, take a press fitting with a thread for cast iron at one end, and a socket for plastic at the other.

Before you start work, prepare a special rubber adapter, which is designed for installation in a cast iron socket; you can easily buy one in any plumbing department. Sewer pipes, as a rule, have the same diameters; you can hardly go wrong. You will need an adapter with a diameter 5 cm or 11 cm. However, there are pipes of other diameters, then you will have to determine its value yourself.

The docking process is simple. The bell is cleaned of rust, dirt and moisture. It is advisable to coat it with sealant. The rubber adapter is also lubricated with any sealant, for example, silicone, and then recessed into the cast iron socket. Attention must be paid to ensuring that it is completely recessed in the socket, i.e. reached the limit.

The end of a plastic pipe is inserted into the adapter - the result is a reliable and easy-to-make connection, easily dismantled if necessary (clean, check), then returned to its place.

Attention! The plastic pipe entering the cast iron socket must have a slope towards the riser.

Connection of pipes with socket

In this case, we will need smooth edges of the pipe. The transition from a cast iron pipe to a plastic one is carried out in two stages. After cleaning the surface of the pipe, a special rubber adapter is put on it, pre-coated inside with sealant. A plastic adapter is put on top of it. The plastic waste pipe is inserted into the plastic adapter. This connection is also removable. Before purchasing adapters, make sure that their diameters correspond to the required ones.

Tip: if a loose connection is detected, it is recommended to use silicone sealant, which can be used to fill existing cracks.

Fitting connection

For it you will need a pipe cutter, which we will use to cut threads on a cast iron pipe. It is assumed that the bell is missing. If the metal already has a thread, the joining process is greatly simplified. If there is no thread, then it must be cut. To do this, lubricant is applied to the pipe, after which the thread we need is cut with a pipe cutter.

FUM tape or ordinary tow is wound onto the finished thread, after which a press fitting is screwed onto it. You need to screw the fitting on by hand, without using a wrench. The point is that wrench It's very easy to overtighten the connection. As a result, the fitting or pipe may be damaged. It will be possible to eliminate a possible leak a little later, after the water is turned on.

As you can see, the process of replacing pipes, as well as joining them together, can be done independently. The most important thing is to work carefully and patiently, adhering to the work technology.

Correct caulking of the fan tee. Dismantling of cast iron sewer. Transition from cast iron to plastic (video)

Replacing a cast iron pipe with a plastic one for a toilet (video)

Sewer pipe socket

Plumbing. How to connect two pipes without a coupling and neck. Experiment

Replacing a cast iron pipe with plastic in the kitchen

When it is necessary to replace cast iron sewer pipes with plastic products, many homeowners are interested in how such work should be done. According to experts, such a connection can be made using a press fitting or using one of four methods of simple joining without it.

All of the above methods provide reliable pipeline repair.

Simple connection of cast iron and plastic sewer pipes

Method one - using a rubber gasket. If old pipe It can be removed from cast iron without any problems, and the inner surface of its socket (cuff) is smooth, then you can use a simple connection method using a special sealant. The plastic pipe needs to be inserted into the cast iron pipe by 3 centimeters, or better yet, by 8 centimeters.

The connection in both cases is made using the same technology, for which:

• first remove rust and dirt from the cuff;
• to the rubber transition located with outside cuffs, apply sealant (read also: " ");
• a rubber adapter is inserted into the cast iron socket;
• place a new plastic pipe in the cuff.

In the case when the connection is made with a pipe without a socket, then you need to use a plastic adapter.

In this situation, proceed as follows:

• a part of the cast iron pipe is cut off using a grinder and the edge is leveled, after which a rubber adapter is put on it;
• the “dressed” edge of the pipe is coated with sealant;
• A plastic adapter is placed on top of it, also treated with sealant (read also: " ").

The size of the cuffs and transitions must correspond to the diameter of the pipes used. The connection of cast iron and plastic sewer pipes according to the transition technology is no different for products different diameters.

In this case, the work is performed in the following sequence:

• at the junction, plumbing tape is wound onto the plastic pipe in several layers;
• using a wide screwdriver or a narrow spatula, firmly push the winding into the gap formed between the pipes (this is the work called caulking);
• the place of transition to a cast iron pipe is coated several times with a polymer-cement solution consisting of water, PVA glue and cement;
• After completion of work, the sewerage system should not be used for at least one day.

The joint, which is made in this way, is quite reliable and was used everywhere before it appeared on the domestic market. construction market silicone sealants, and now it is still used if you need to connect a plastic pipe to a cast iron pipe in a place under a washbasin or sink. Using high-quality sewer pipes and fittings, even after several years of using this method, leaks do not occur at the junction.

Method three - sealing using plumbing silicone. When connecting a plastic pipe to a cast iron pipe, a small gap may form, the dimensions of which do not exceed 2 millimeters. Then replacing sewer pipes from cast iron to plastic using this method turns out to be very effective (more details: " "). Special attention When carrying out work, care must be taken to ensure the tightness of the joint in its lowest part.

Docking in accordance with this method must be performed in the following sequence:

• Before connecting a cast iron sewer pipe to a plastic one, thoroughly dry the joint using a hair dryer;
• The gap between the ends of the pipes is filled with silicone using a construction gun. The deeper the sealant penetrates, the stronger and stronger it will be. more reliable connection between pipeline elements;
• The silicone layer needs to dry well. Typically, it takes about 3-5 hours to dry completely, depending on the thickness of the silicone applied. The joint can be coated with it both from the inside and from the outside, as in the photo. You should not use the sewer until the silicone dries.

Method four - combining the three methods described above. In order to increase the reliability of the joint between plastic and cast iron pipes, it is permissible to combine the methods described earlier in the article. For example: if there is big gap between the pipes at the junction, caulking and rubber gaskets can be used.

When connecting the toilet to sewer system with the help corrugated pipe use caulking with linen winding and then cover the joint with sanitary silicone. At the same time, the same material is used to coat the cast iron crosspiece located at the junction and the rubber seals. When caulking, the polymer cement solution can be replaced with silicone sealant.

How to connect cast iron and plastic using a press fitting

Press fitting- this is a transition element for cast iron pipes with a thread for these products at one end, and on the other side there is a socket for sliding connections of plastic elements. When using it, you will need tow or Teflon tape.

Process connecting pipes using a press fitting:

• first of all, using a grinder, cut off the old pipe or unscrew the coupling on the pipeline at the place where there will be a joint with plastic element;
• lubricate the edge of the pipe with grease or oil to the place where it comes out of the die;
• using a thread cutter, cut the thread, then wipe it and wrap FUM tape or tow on it, smearing the winding with silicone;
• Then screw the press fitting onto the thread by hand. Tighten it after turning on the water supply if a leak occurs at this location.

Before inserting a plastic sewer pipe into a cast iron one using a press fitting, you need to take into account the difference between the coefficients thermal expansion cast iron and plastic. For this reason, experts do not recommend screwing fittings made from polyvinyl chloride onto a metal base.

By following all the rules for connecting plastic and metal pipes, you can do this kind of work efficiently. on our own without inviting professionals.