How to make the transition from a cast-iron sewer pipe to a plastic one

In modern buildings, the internal sewer system is assembled from plastic pipes. They have several advantages and are easier to install, as there is a wide variety of fittings that allow you to make turns, connections and transitions from one diameter to another. In a completely different way, the problem of replacing old rusted elements with polymer products is being solved. In this case, an adapter for a cast-iron sewer pipe is needed, with which it will be possible to dock the plastic with the metal.

Definition and purpose of sewer taper

Adapters from cast iron to plastic fulfill two purposes: they connect elements of different diameters and from various materials. They are used in external and internal sewer systems. By design, they are divided into 2 types:

• concentric connecting vertical risers;
• eccentric, serving in horizontal connections.

Plastic transitions, depending on the purpose, have a different design:

• Couplings are used for joining products of the same size. They are made in the form of a barrel, the inner diameter of which corresponds to the outer section of the pipes.
• Corners with rotations of 45 - 90 degrees, having threads on one side.
• Tees and crosses that allow you to perform wiring of various configurations with different diameters.
• Contours - the shape of the product helps to go around the obstacle in the form of pipes to reduce the number of elements.
• Compensators withstand water shocks and temperature differences.

The connection of plastic adapters is carried out by welding, threading, gluing, using elastic seals.

To quickly connect polymer pipes to cast iron wiring, rubber or polypropylene cuffs are used with external and internal connections. In the presence of a metal bell, an adapter is inserted into it, the outer cross section of which corresponds to the internal diameter of the expansion of the pipeline element, so the use of sealant is not required. In the absence of a funnel, an external cuff will have to be used.

Production material

Various adapters are used for adapters:

• cast iron;
• steel;
• polypropylene;
• polyvinyl chloride;
• rubber.

Modern fittings made of gray cast iron are coated with a bitumen mixture, which protects pipes from corrosion and cracking during temperature extremes. The strength of the products allows them to be reused. They are well connected with all kinds of plastic products. The disadvantage of heavy construction.

PVC adapters connect pipes of any configuration from plumbing to the output in the riser. Products allow you to connect and change the flow direction, switch from one pipe size to another. Polyvinyl chloride can withstand temperatures of 60 degrees and is resistant to dissolved chemicals.

Polypropylene has several advantages over the other materials used. The polymer can withstand temperatures of 80 degrees, for a short time within one minute - 95 degrees. In the effluent, an acid-base equilibrium pH of 2 to 12 is allowed. However, before installation it is necessary to check the products for stability in specific conditions. Polypropylene adapters are corrosion resistant and have a minimum weight. The material withstands shock loads.

Product Dimensions

Plastic tappers have the following running diameters:

• 50/75;
• 110/124;
• 50/75 with a cuff;
• 50/72 with gasket;
• 110/124 with gasket;
• 110/125 with gasket;

Polypropylene:

• transitional cuff: 50/32/50;
• taper 50/75 with 2 sets of a sealant.

Rubber junction:

• 50/32 for connecting washing machines;
• 50/40;

Elastic products withstand temperature extremes and retain the tensile property of the material from 0 to 72 degrees.

Installation Rules

There are several ways to connect. The choice depends on the possibility of caulking fasteners. In addition to a rigid fitting, rubber sewer products are used - cuffs or reductions. They find their application when connecting washing machines and dishwashers, the drain holes of which have a diameter of 32 mm.

Experts do not recommend using silicone, linen cables or sealants when joining plastic products. They are successfully replaced by sealing rubber rings. If leaks appear after installation, adjust the skewed ring.

Elastic gaskets have a fairly high rigidity, so installation difficulties arise. In this case, the end on which the seal is put on is coated with a liquid detergent.

Rubber cuff

If the old pipe was pulled out of the socket easily and the integrity of the cast iron surface was preserved, the end of the plastic pipe is inserted at the extension of 3 or 8 cm. A quick and high-quality connection can last 8 years.

For plumbing fixtures that are located close to each other, there are 2 outputs to the riser. One with a diameter of 100 mm is used when connecting drains from a bidet and a toilet, the second - with d 50 mm, for sinks, bathtubs and shower.

The algorithm for attaching polymer wiring to a cast-iron socket:

1. the inside of the cuff is cleaned of rust and dirt;
2. to prevent leaks, apply a sealant on the outside of the rubber product;
3. insert tape.

At the last stage, a connection is made to the polymer pipe.

Plastic fitting

Sewer adapters from cast iron to plastic are used in cases where the cut of the metal pipe does not have a bell. In addition, molded products often have diameters different from the standard, for example, 60 mm. The connection is performed using a taper 50/72 mm.

According to the scheme, the assembly looks like this: a plastic pipe, a 50/50 coupling, a rubber ring, an adapter 50/72, an elastic sleeve, a gasket, a cast iron pipe d 60 mm.

Procedure:

1. the old metal pipe is cut evenly;
2. put on a rubber cuff on the stripped end;
3. apply sealant to its inner edge and the upper part of the plastic fitting;
4. insert the adapter into the seal.

It remains to insert the polymer pipe into the prepared end through the connection sleeve. The size of the cuff and taper should match each other.

Chasing with an Asbestos Cord

The method is used when connecting cast iron products, since the configuration of casting fittings is limited. Operating procedure:

1. the rope is wound on plastic;
2. the wrapped end of the pipe is inserted into the cleaned hole, helping with a screwdriver to close the cracks with asbestos material;
3. prepare a solution of water, cement and PVA glue;
4. Coat the dock with a cementitious compound.

It is recommended to wait a day before using the sewer for drying. This method has high reliability and guarantees leak-free operation for a long time. So connect the cast-iron sinks with a plastic pipe.

If the pipes have a different diameter and the gap between them is large, in addition to the winding, a rubber gasket is inserted. Instead of mortar, you can use building silicone.