Heating water pipe sewage: systems of cast iron, polymers,

This article is a miniature review of the key properties used in plumbing materials. We have to find out what kind of pipes and fittings are installing the plumbing of sewage and heating, and get to know their main problems. So go.

Sewage

Cast iron

Let's start with the waste systems. The traditional material for their installation - cast iron socket pipes.

Nowadays they can be found in three versions.

1. Traditional sockets for chasing assume sealing with organic fiber (cabol) with resin or bitumen impregnation. The pipe after embossing is sealed with cement mortar or molten sulfur. Long, inconvenient and unreliable: over time, the sockets often leak.

In addition: minting the connection against the wall - to put it mildly, a dubious pleasure.

1. Products with rubber seals much more practical: the connections are easier to assemble and remain sealed for longer. Among the shortcomings, it is worth noting the great effort required to press the pipe into the socket.
2. Pipes from VChShG (ductile iron with nodular graphite) differ from gray iron less brittleness and greater ductility. In fact, they combine the advantages of iron and steel - strength and corrosion resistance. Again, sockets with rubber seals are used for the connection.

Polymers

Modern plastics are less durable than cast iron; However, the high durability and low price of polymers forced the traditional material to make room. All polymer pipes for gravity drainage are bell-shaped, with annular rubber seals, which greatly simplifies their installation.

By the way: the simplest instruction will help reduce the effort required to assemble the socket connection. Remove the outer chamfer on the pipe inserted into the bell and lubricate the rubber ring with liquid or regular soap. If the effort is still too great to do the work with your own hands, assemble the simplest structure of the clamp and the lever.

Here is a brief overview of the key properties of popular polymer sewer pipes.

By the way: the so-called silent multilayer pipes made of polypropylene and PVC can be found on sale, including a layer of increased density. By the ability to absorb acoustic vibrations, they approach the cast iron.

Water supply and heating systems

What is installed heating and plumbing?

Metals

The list of types of metal pipes is not too large:

• Black steel. Connected by threads and welding (gas and electric); It is resistant to corrosion. Service life - no more than 25 years.

Curiously, electrowelded VGP pipes with damaged paintwork often need to be replaced after 10 years of operation.

• Galvanized steel more expensive than black by 30 - 50%. It is reasonable to use only threads for the connection: welding breaks the zinc coating, depriving the overpayment for the corrosion resistance of any meaning. Mounted galvanized plumbing on threaded fittings plumbing and heating, even after half a century of operation, differ little from new ones.
• Copper even more durable: the oldest copper water pipes have been in operation for more than a century. Connections are made by pre-flashing or compression fittings. Copper does not overgrow with sediment, but is vulnerable to mechanical damage.
• Corrugated Stainless Steel It has the strength and durability of copper, but compares favorably with it by simple installation using compression fittings with high-temperature silicone seals.

In addition: the corrugation allows to bend the pipe with a radius equal to its diameter.

Polymers

Modern plumbing systems, heating and plumbing in general, are increasingly mounted with a predominance of synthetic materials. Which ones?

Polyethylene due to limited heat resistance is applied only on cold water. Pipes of small diameter are connected by compression or electrofusion fittings. In the latter case, the coupling fitting has its own heating element that fuses the adjacent surfaces of the fitting and the pipe when the voltage is applied to the contact terminals. Trunk water pipes are boiled end to end.

Cross-linked polyethylene (with cross-links between molecules) is characterized by greater mechanical strength and heat resistance: the working temperature reaches 100 degrees and higher. Molecular memory causes the stretched tube to return to its original size, which allows you to connect the pipe fittings.

Polypropylene is used here; however, hot water, heating and sewage are mounted by pipes with different structures. Intended for work at high temperatures, products are reinforced with aluminum foil or chopped fiberglass (fiber). Connection method - low-temperature socket welding.

Two in one

Plumbing and heating are often connected by another very popular type of pipe - metal-plastic. It is a three-layer structure of cross-linked polyethylene and aluminum. The obvious advantage of the solution is simple installation using compression or press fittings; minus - limited flexibility and stringent requirements for installation technology.

To clarify: the displacement of rubber seals due to the ovality of the non-calibrated pipe leads to the fact that tightness is ensured only by clamping the polyethylene inner shell to the fitting. With cyclical heating, such a connection often leaks.

Conclusion

We hope that our, albeit somewhat superficial, acquaintance with the features of modern materials will help the reader choose the optimal solution for him. Attached to the article video will help in this.