Galvanized steel pipe: technical parameters and

04-05-2018
Pipes

The main enemy for any metal product is corrosion. And reliable protection is galvanized steel pipe, which today is used in many areas of human life, for the installation of various types of pipelines and the construction of frames. The price of such treatment is several times lower than the cost of other methods of protection against rusting processes.

In this article we will try to consider the methods of manufacturing and the scope of galvanized steel.

Steel Metal

Normative documents

Let's start with the most secret and mysterious, the fact is that such materials do not have their own standard. And so it turns out, the product itself exists and has been produced for a long time, but the GOST for a galvanized steel pipe simply does not exist.

Note! For a long time, the production of galvanized pipes has been conducted in accordance with the standard for steel pipes, from which the product mix was borrowed.

In fact, galvanized materials are manufactured in accordance with the following documentation:

  • Production of steel pipes according to GOST 3262 75;
  • Galvanized pipes according to GOST 10704 91 longitudinal electric-welded.

If everything is clear with the first standard, then it is completely unclear why the second GOST is used for galvanized pipe? To explain it is quite simple. The fact is that pipelines are often exposed to aggressive external influences that lead to corrosion, namely welded longitudinal welded pipes are best suited to solve this problem, i.e. they have a low price, but they are perfectly protected from corrosion.

Note! There are no bans on the production of such materials - spiral-type or seamless, there is no need to manufacture high-strength and thick-walled galvanizing. And the installer can produce cold galvanizing after completion of the work.

Pipe manufacturing

Instructions for the production of galvanized metal from steel corresponding to both standards allows you to create tubular products by the electric method.

It consists of the following stages, which answer the question of how to make a galvanized pipe with your own hands:

Strip cutting
  1. The raw material for such production is strips (flat sheet metal), which comes to production in the form of rolls. These rolls are unwound and cut in strips along;
  2. After cutting, the strips are welded to an endless belt, which is wound on a specialized drum.. This procedure ensures the continuity of further production;
  3. With the help of rollers a round billet with an open seam is formed.;
  4. Next, the resulting workpiece must be welded along the seam. One of the following most popular methods can be used for this:
  1. HF - induction welding, one of the cheapest;
  2. TIG - welding using a tungsten electrode, in an argon atmosphere.

Note! TIG welded pipes are considered to be as reliable as possible due to the fact that welding is performed at a lower speed. In the process, the arc of the apparatus manages to melt a large surface around the seam. However, the reliability of cheaper materials is enough, for example, for heating or plumbing.

Production Line
  1. The hot product after welding is dipped in cold water.;
  2. Next, the pipe passes the inspection in the flaw detector, which detects weld defects;
  3. Next, the pipe pass on the calibration rollers, which eliminate defects in shape and size;
  4. Next, the resulting pipe is cut into segments of a given length;
  5. Another control operation, which consists in visual inspection;
  6. Finished products are packed and shipped to the warehouse..

Galvanizing process

Hot galvanized on the photo

But galvanized steel pipes are not just welded steel, but also a corrosion-resistant coating.

Let's find out how to galvanize pipes:

  • Hot coating method - from the point of view of layer uniformity and protective characteristics, this method is considered the best. To implement it, it is enough just to dip the pipe into a bath with hot zinc;

Note! There is a limitation to this method, and it cannot be applied if more than 0.2% of carbon is present in the metal.

  • Galvanizing - the product is immersed in the electrolyte, where a potential difference is created between the steel and the zinc electrode. The result is a reliable uniform coating, the thickness of which is easy to control;
  • Gas thermal technology consists in spraying a melt of zinc, which is sprayed onto the surface under the influence of hot air;
  • Thermal diffusion, as a method of galvanizing, involves the transfer of zinc to a gaseous state at high temperature, after which its molecules tend to settle on the surface of a cold pipe;
  • Cold zincing can be used to treat surfaces of any type other than the internal diameter of the pipe. In this case, the zinc powder is diluted in varnish and applied as a paint on the product from a can or spray.

Despite the wide variety of modern materials for anti-corrosion treatment, zinc is still the best option for plumbing, gas or heating. (See also the article Sewage system: features.)

Council A galvanized metal pipe of 32 or 100 mm is much better than its plastic or composite counterparts due to its high operating temperature and resistance to mechanical stresses. Installation of galvanized pipes procedure is not so time consuming to refuse it to the detriment of the quality and reliability of the created system.

Finally

Large diameter products

If you need a reliable and durable pipe that is resistant to rusting processes, then without hesitation you can opt for galvanized steel pipes. Well, if the created pipeline needs to be insulated, then a galvanized casing for pipes, which is also resistant to corrosion, should be purchased for the insulated area.

The main thing in the process of buying to pay attention to the integrity of the coating. And the video in this article will reveal to you even more subtleties of the choice and installation of structures made of galvanized metal.