Cast iron pipes for sewage: advantages and various

Despite the fact that recently the main part of the market is made of plastic products and technological ceramics, cast-iron pipes for sewage systems, as well as steel with anti-corrosion coating, continue to be used quite widely. In our article, we will consider the features of these products, paying particular attention to the operational advantages and effective installation technology.

Features of cast iron sewer networks

Regulatory requirements

The manufacture of parts for cast iron pipelines is regulated by a number of regulatory documents. The most commonly used GOST 6942-98, which determines the method of manufacture and technical characteristics of pipes, but in parallel with it you need to focus on other standards.

According to these standards, products must meet a number of requirements:

• Nominal diameter - from 65 to 1200 mm.
• Product length - from 2 to 6 m.
• Wall thickness - from 6.7 to 31 mm. Depending on this parameter, details of classes LA, A and B (the heaviest and reliable) are distinguished.
• The design working pressure is either 1 or 1.6 MPa. When checking the design passes the test under pressure from 2.5 to 4 MPa.

Note! Non-pressure varieties (GOST 6942.0-69) are produced under a working pressure of not more than 0.1 MPa.

• Connection - bell-shaped or flange.
• Pressure cast-iron water pipes according to GOST 9583-75 can have a different configuration of the external socket part: it can be made in the form of a slope or in the form of a ledge. At the same time, a step is necessarily formed inside the socket for a more reliable connection.

Such pipes are made by the method of semi-continuous or centrifugal casting in sand molds. The use of these technologies allows to obtain products with more durable and reliable walls that can more effectively withstand internal pressure.

Installation of socket systems

Instructions for the installation of sewer pipelines largely depends on what kind of pipes we will use for the rhenium of this task. In this section, we will focus on assembling the flare system, and we'll discuss the non-socket varieties below.

Installation of cast iron sewage pipes is carried out thus:

• The end of one pipe is inserted into the extension of the other until it stops and leveling.
• The gap is filled with tow, hammering it with the help of a special shovel and a wooden hammer. Approximately 2/3 of the volume you need to lay the material impregnated with grease or other lubricants, and in the upper third - dry fibers.
• Then we perform sealing using cement mortar (the grade must not be lower than M300 - M400). Compress the solution, then cover with a damp cloth.
• Full drying takes about a month, but after one and a half to two weeks, you can expose the communication to operational loads.

In addition to the described procedure, it is allowed to seal joints between parts using moisture-resistant silicone-based sealants. The caulking (i.e. clogging of the socket) with lead is also reliable, but this technique has recently been increasingly refused, taking into account the toxicity of the metal and the possible harm to the environment.

Dental sewers

The SML Beozrastrubnaya system, which is used in modern construction, can also be assembled by hand.

• For connection, a clamp is used, consisting of a metal clamping part with one or two screws, as well as an internal sealing gasket made of chemically resistant rubber.
• During installation, two sections of the pipeline are laid butt-joint, after which a clamp is applied on top, and fasteners are tightened.
• Conventional clamps are designed for use in non-pressure systems with pressures up to 0.1 Bar. However, when installing crimp cups of a special configuration, the upper pressure limit can be raised to 10 Bar - true, and the price of this design will increase significantly.

The use of this technique facilitates not only the laying of communications, but also the replacement of a damaged section: to remove a pipe, it is enough to loosen several screws.

Features of the operation of iron

Water cast iron pipes, as well as products that are used in the installation of drainage systems, have several advantages.

Among the most relevant are:

• First, the material itself is distinguished by high corrosion resistance in order to distinguish it favorably from steel.
• Thick walls of the structure provide it with a margin of safety, which is one of the conditions for the durability of the entire system..

Note! In addition, by increasing the wall thickness, the noise level is reduced, even when draining large masses of water.

• The cast-iron pipe does not burn, does not melt, does not emit toxins when heated. Also, the material is characterized by minimal temperature deformations, because the finishing of plaster materials around the pipeline does not collapse over time.
• The use of modern clamps for drill-free installation allows for maximum tightness of all joints.

However, do not forget about the minuses:

• Despite its mechanical strength, cast iron does not tolerate impact. So there is always a risk that the pipe will crack either as a result of a heavy object falling on it, or from vibration.

Note! For this reason, it is absolutely not recommended to use this material for arranging communications in areas with high seismic activity.

• Cast iron has a significant mass, and therefore it can only be mounted on structures with a good bearing capacity.
• Repair of cast-iron plumbing pipes is much more laborious than restoring the integrity of polymer or steel communications. Welding does not work here, so you have to either change the entire pipe, or apply a collar with a sealing gasket.

Conclusion

Using cast-iron pipes for external sewage according to GOST, we provide a substantial safety margin to the erected drainage system. Of course, the installation process will be much more time consuming than when using polymer or metal-plastic products, but such communications will not last longer (see also the article Cast iron sewer pipes: their types and 4 basic operating rules).

So if the extra work does not scare you, and you decide to use this material, we recommend that you carefully study the video in this article for more information.