Not a single overhaul of a house or apartment is complete without replacing communications. So, special attention is paid to the sewer system. Today, many people practice joining sewer plastic pipes. Cast iron has long been a thing of the past. They were replaced by more modern materials. Well, let's look at how to connect plastic pipes for sewage correctly.
Types of Plastic Pipes
To begin, consider what kind of communication exists. On the market you can find different products:
- Products made of polyvinyl chloride. They are marked with PVC. They are the most popular pipes. They are used universally both in the economy and in industry. Differ in the lowest cost. At the same time they have an attractive appearance, due to which they are used in open systems. Typically, the connection of plastic sewage pipes is performed by fittings or welding. But polyvinyl chloride products are cold-bonded. For this, a rubber cuff and plumbing glue are used. The result is a reliable and tight connection of sewer plastic pipes. Such products are not afraid of climate change, but it is better to use them in a cold environment. Such pipes are not suitable for heating, as they melt at temperatures above 80 degrees. In this case, it is better to use chlorinated PVC. These pipes are designated CPVC.
- Products made of polypropylene. These are strong and at the same time quite light pipes. They are suitable for various purposes, including sewage. But among the minuses, poor flexibility should be noted. Such material is not elastic. To make turns and bends, you need additional tees and corners. Due to the multilayer structure, the material withstands temperature extremes. The connection of sewer plastic pipes is carried out by heat welding. The result is an almost monolithic junction. But you need to understand that this connection is not separable.
If polypropylene pipes have been selected, the installation must not be allowed to overheat the material. So, it becomes very fragile, and the connection does not last long. Poor connection may also be due to the presence of water and dirt in the workplace. The surface should be as clean and free of moisture as possible.
Polyethylene
This is another type of plastic pipe. They can be used in areas with increased seismic activity, as they are very flexible. There can be two types:
These are low and high pressure pipes, respectively. The first type is usually black. The installation of such communications is not recommended at temperatures below +5 degrees. Material loses flexibility at low temperatures. Installation is carried out by means of compression (crimp) fittings or by the method of electric welding.
It is worth saying that such pipes can also be used for an external sewage system. But it is additionally recommended to install the insulation so that the material does not suffer due to severe frosts.
Typically, the connection of a cast iron sewer pipe with a plastic pipe is done through fittings. This element allows you to get a high-quality and tight connection. This design will not allow water and odors to leak. Such elements do not need repair.
Fittings Features
There are several varieties of them. Products differ:
- By design (extension cords, turn signals, tees and couplings).
- To destination (connecting and intermediate fittings).
- Shape (L-shaped, straight and T-shaped elements).
When inserting the pipe into the fitting, the rubber gasket should be put in the joint.
What is taken into account before connecting?
You need to understand that sewer pipes are part of a large system. Therefore, you first need to:
- Create a system drawing. Be sure to take into account all the facilities where the connection will be provided (toilet, shower and bath).
- Determine the junction of the pipes with the riser. This is where fittings are required. So, a connection can be made of sewer plastic pipes of 110 millimeters or 50. The latter option is optimal for a washing machine, shower, bath and sink.
It is not worth taking this material with a margin, as it will be difficult to damage it. But you need to purchase a turn signal fitting. He will connect the hose extending from the plumbing fixture and the sewer pipe. If this element is not used, it will be difficult to obtain a tight connection. Because of this, a puddle often occurs at the junction in the bathroom or in the kitchen.
What else do you need to pay attention to when connecting sewer plastic pipes?
- Possibility of providing a bias of pipes is provided. This contributes to faster fluid drainage. This slope is calculated so that the reduction per meter of pipe does not exceed three centimeters.
- The arrangement of the sewer system begins from the devices in the direction of the main riser.
If it is an outdoor sewage system
It is laid on the territory near the house, where a well is necessarily used. Such a construction facilitates easy cleaning of the sewer. To clean it without problems, you need to use large diameter pipes. If the sewer pipe cuts into the outside, the size of the latter increases. It is recommended to take the product with a margin so that if necessary, the connection of new plumbing does not change the entire system.
After finishing the preparatory work, you can get down to business. Types of sewer pipes and connections foresee two options for performing work: detachable and one- piece connections.
Methods
What are the ways to connect a plastic sewer pipe? There are several of them:
- Detachable.
- One-piece method.
Next, we will talk about each in detail.
Detachable way
Plug connections of plastic sewer pipes can be:
Experts recommend using the first method for PVC pipes. And in order to make the connection of a cast-iron sewer pipe with a plastic one, an additional rubber gasket is used. Work is carried out step by step:
- The pipe is cut. The cut should be as even as possible. A chamfer is not done.
- The loose flange fits over the cut.
- A rubber gasket is installed. It is mounted in such a way that it protrudes from the cut by 10 centimeters.
- A flange is applied to the gasket.
- Connection with mating flanges is in progress.
- Bolts are fixed.
Coupling connection
It can be used both for the installation of pressure and unsupported systems, and during repair work. For this we need:
- Cut off at the right angle the ends of the elements that need to be connected.
- Attach a sleeve to the fitting. This is done so that the central part is at the junction of the pipes.
- Pipe marking is performed. This mark must correspond to the position of the coupling.
- The ends of the pipes and the sleeve inside are treated with grease.
- The pipe is installed in the coupling until it stops. The second is mounted in such a way that the axis seems to be single.
- On the second sewage pipe, the coupling slides up to the mark made earlier.
This connection method allows you to parse communications if necessary. But during installation, special attention is paid to the tightness of the joints.
One-piece method
Such connections can be made in different ways:
- To the bell. To do this, you need to connect the bell with the smooth end of the pipe and with the rubber ring. Previously, the surface is cleaned of dirt and degreased. In this case, the chamfer is necessarily removed from the smooth end. The surfaces that join are treated with silicone grease. It is important that the longitudinal axis of the elements coincides. A smooth end is installed in the socket. The pipe must not be retracted beyond the installation mark.
- By welding (butt and socket). In the first case, the ends are melted, which will be connected, and the place of fasteners is melted. In this case, there must be a confident pressure. In the second case, the internal part of the bell of one pipe and the external surface of the second are fused with a welding machine.
- By bonding. To do this, you need a special glue. They need to grease the ends that connect. The choice of glue depends on the material of communications. So, if the toilet is connected to the sewer from plastic pipes, BF-2 is used. If metal and polymer pipes are used, epoxy adhesive is used. Metal and rubber are connected by 88N composition.
Most reliable option
According to reviews, the simplest type of connection is to socket. Even a beginner can handle this job. But in order to get a tight connection of a cast-iron sewer pipe with a plastic one, you need to use the rubber ring of the bell. The bell should be directed in the opposite direction from where the water will be directed.
By the way, if there is no grease for pipes at hand, you can use ordinary liquid soap or household detergent.
As for welding, this is a very complicated way. This will require a special soldering iron. But this type of connection is the most reliable. You can apply glue. This is the key to high bond strength. But first, the surface must be cleaned of dirt, and also degreased.
Fittings are fixed by means of o-rings. The method is quite simple and is suitable for small diameter communications. But the fixation must be performed in such a way that there is constant access to this area. So, if necessary, you can get rid of blockages. If pure plastic pipes are connected, they do not need additional preparation.
How to connect a plastic sewer pipe with a metal one?
To do this, resort to the use of rubber gaskets. This is possible if, after removing the old pipe, the inner surface of the cuff remains flat. In this case, the plastic pipe is inserted into the metal pipe by 3-8 centimeters. Thus we get a quality connection. The service life is at least eight years.
Typically, a sewer riser has two exits. The first has a diameter of 50 millimeters, the second - 100. One outlet is used to connect to the toilet, and the other to connect the drain, which provides the conclusion of the apartment sewer. But in both cases, the connection will be the same. How are sewer plastic pipes connected to metal pipes? To do this, you must:
- Remove all dirt and rust from the socket.
- Apply sealant to the outside of the cuff.
- Install the rubber adapter in the metal sleeve.
- Install a new sewer pipe in the socket.
If you have to work with a pipe that does not have a bell, you need to use a special plastic adapter. How is the connection made in this case? To do this, you must:
- Cut off part of the metal pipe with a grinder, while aligning the edge.
- To put on a rubber adapter on this part.
- Seal the pipe edge with sealant.
- Install a plastic adapter on top. The latter is also treated with sealant before joining.
We carry out sealing with sanitary silicone
If a small gap (no more than two millimeters) is formed when connecting the cast iron pipe to the plastic one, you can use this method. But special attention is paid to sealing the joint at the bottom. Before docking you need:
- Dry the joint thoroughly. Use of the building hair dryer is allowed.
- Drive silicone into the gap between the pipes. This is done with a construction gun. Keep in mind that the deeper the silicone penetrates, the more reliable and tight the connection will be.
- Time is expected - from three to five days. This is necessary so that the silicone is completely dry. Only after this can you begin to operate communications. It should also be remembered that a thicker layer requires more time to dry.
Here's how the joints are sealed when installing metal and plastic pipes in a sewer system.
Conclusion
So, we found out what types of plastic sewer pipes and joints are. As you can see, there are many ways to install pipes. The main thing is that the connection is reliable and tight. After all, if there is a slight breakdown, the smell from the sewer will spread throughout the room.