GOST 8732-78 Hot-deformed seamless steel pipes. Assortment

Electric-welded steel pipes GOST 10704-91

Electric-welded steel pipes with a diameter from Ø10 (mm) to Ø1420 (mm) in accordance with GOST 10704-91. The pipe has a wall thickness from 1 to 32 (mm), weighing from 0.222 to 779.7 kg per 1 running meter.

Electric-welded steel pipes with a diameter from 10 to 1420 (mm) according to GOST 10704-91

How to deal with import designations

There are not only products from domestic manufacturers on the market. There are pipes marked according to the American system. Let's start with the fact that they distinguish between two types of pipes: pipes and tubes. Both words translate as pipe, but they are intended for different systems and the requirements for them are different.

Pipes type

Type of Pipes - electric welded and seamless. They are designed for transporting liquids and gases. So this is exactly the type that can be used in our heating and water supply systems. The main characteristic of pipes type pipes is the internal diameter. There are two strength standards in this group, which determines wall thickness and operating pressure.

• Schedule 40 or standard. The designation may include st (as in the figure below). These are products with standard wall thickness.
• Schedule 80 or extra heavy. The designation is EX. This is a material for use in high pressure pipelines.

Difference in internal diameters of Pipes of different strength categories: standard and heavy

As you understand, with the same external size, the clearance will be different. Let's take a two-inch pipe as an example. It is designated as NPS=2″ internal diameter in different designs differs:

• standard (standard) schedule 40 - 2.067 inches (which is approximately equal to 5.25 cm);
• extra heavy schedule 80 - 1.939 inches (approximately 4.925 cm).

These categories standardize wall thickness and maximum operating pressure. The outer diameter remains constant, but the actual inner diameter changes with the wall thickness. That is, NPS=2″ describes the inside diameter, which will be about two inches, but will vary depending on the wall thickness. Here the situation is similar to our standards: there is a certain list of values ​​to which actual parameters are rounded when labeling. Once again: if we are talking about a two-inch Pipe type pipe (the marking says NPS), you need to understand that we are talking about the internal diameter, but it will not be exactly two inches. It will be either a little more or a little less. Same with other sizes in inches.

Type Tubes

The word Tubes refers to pipes that are marked by outer diameter. The internal one will depend on the wall thickness. Therefore, this standard also contains the concept gauge, which can be translated as gauge. It just indicates the wall thickness.

The same diameters of steel pipes do not mean the same weight

The marking is marked with ASTM. The numbers following the abbreviation describe the outer diameter. In this group, we may be interested in copper pipes.

Steel pipe range

1. D(mm) - Pipe outer diameter
2. Din (mm) - Inner diameter of the pipe
3. t(mm) — Wall thickness
4. F(cm²) — Cross-sectional area
5. M (kg/m) — Nominal weight of 1 m of pipe
6. Wx,y(cm³) — Moment of resistance

Techniques for making simple and original potholders

Any idea should be implemented by a home craftswoman using diagrams and sketches, which greatly simplifies the work process. Original and unusual products, along with traditional models, can be made using different techniques:

• Crocheting is an original and uncomplicated technique used for making potholders of various shapes and differing in aesthetic appearance;
• simple stitching, the technique allows you to make products that are not complex in design, used to decorate the kitchen and protect your hands from hot surfaces;
• patchwork and patchwork techniques are used to create real works of art, with minimal expenditure of materials and your own time.

The easiest way to make a potholder is to sew several layers of fabric and be sure to use insulation. Crochet products look festive and original; they use strong and dense threads that do not ignite easily (smolder, but do not burn).

Brands and guaranteed parameters

The tables contained in the regulatory documents for pipe products made from stainless steel contain various parameters. In particular, from these tables you can take information about the grades of steel used for the production of such pipes.

Permissible deviations from dimensions must be within the values ​​​​specified in the table

Knowing the brand of material from which the pipe is made allows you to get an idea of ​​which of its parameters are guaranteed. These include in particular:

• A – mechanical characteristics of the steel used;
• B – its chemical composition;
• B – the relationship between the chemical composition and mechanical properties of the alloy used.

Diameter

The outer and inner diameters of steel pipes have different characteristics. They may be as follows.

1. Conditional. Displays the nominal internal dimensions.
2. Nominal. This is the actual size of the dimensions.
3. Outer. This value is the main one when classifying large-volume products.
4. Internal. This value is very important when choosing connecting elements for large volume pipes.

At the same time, the indicator of wall thickness for pipe-rolling materials of this type becomes no less important.

Certain fixed values ​​for the outer diameter of these products are also known. They make it possible to select the required dimensions, taking into account the preliminary tasks of the structure being designed.

In reality, the outer diameter plays a significant role in certain situations. For example, when constructing units for drainage in premises, because in this situation fasteners are selected taking into account the values ​​of the outer diameter of the main elements.