Pipes

Diameters, sizes and prices of polypropylene pipes

At the stages of designing cold and hot water supply points, internal and external sewage, a correctly selected polypropylene pipe is required - diameters, table, price and the required amount of material depend on the purpose of the main (domestic or industrial).

Sizing based on pressure

When choosing PP pipes, water pressure is of great importance. With insufficient pressure, lines with a smaller cross section are selected. As the amount of liquid transported increases, a larger diameter is required. When studying the marking of PP, special attention is paid to the value of N25, N10, etc. It allows you to assess the stability of the material, relative to the water pressure in the line. High-quality PP pipes serve up to 20 years or more.

Types of PP pipes:

РN10 - pipes are designed for a working pressure of 13 atm. and material thickness from 1.9 to 10 mm. They are well operated when laying the "warm floor" system and supplying cold water. The maximum heating temperature is +45 gr. Cross-section of PP pipes: external 2…11 cm, internal 1.6…9 cm.

PN16 is a less commonly used design option that provides a pressure on the wall of 16 atm. It is used for cold and hot water supply with maximum heating temperature up to +60 gr.
N20 (PN20) - products with a thickness of 16 ... 18.4 mm are the best solution for arranging a heating system and water supply with an allowable water temperature limit of 80 gr. Polypropylene water supply system with a pressure level on the walls of 2.0 MPa, is characterized by an external diameter of 1.6 ... 11 cm, an internal diameter of 1.06 ... 7.32 cm.

N25 (PN25) - a water main with a pressure level on the wall of 25 atm. Due to the inclusion of aluminum in the design, these products have ideal characteristics for the arrangement of heating systems, where the water temperature reaches up to +95 degrees. The multilayer structure of the construction determines the high resistance to mechanical and thermal stress. Pipes are produced with an internal section PN25 - 1.32 ... 5 cm, external - 2.12 ... 7.79 cm.

Attention! Marking 10, 20, 25 determines the level of maximum pressure (kg / cm2) on polypropylene pipes. Dimensions, table, price and duration of operation depend on the structure of the material and its reinforcement.

The introduction of new technologies made it possible to obtain a new type of reinforcement for polypropylene pipes - fiberglass. It prevents delamination of the conduit during use, and when laying - the time spent on cleaning cuts after welding. Reinforced products using fiberglass mesh are most in demand, due to the rapid installation of deformation resistance and a long service life without repair.

The main types of pipe sections PP

When carrying out calculations, the internal and external sections are taken into account. Internal parameters allow you to find out the volume of liquid passing over a certain period of time. External dimensions allow you to carry out construction calculations, namely the size of the niche or channel required for the highway. The parameters of the external section are taken into account for the correct selection of fittings in accordance with the internal diameter. All pipe sizes are classified according to the following indicators:

Small cross section - 0.5 ... 7.5 cm. The optimal solution for heating, supplying cold water and discharging sewage in suburban buildings. Pipes with a small diameter are placed in the kitchen, in bathrooms and on common risers. An internal section of 3.2 cm is more common in multi-apartment buildings.
Average section - 8; 9; ten; eleven; 12.5; 16; twenty; 25; 31.5 cm. It is used for arranging water supply and sewerage. Internal section 8, 9 and 10 cm, serves to move chemical products.
Large section - 40 cm or more. It is used for water supply and ventilation.

Pipes are marked in inches and mm. For convenience, you can use the conversion table:

How to determine the diameters of the PP line, based on the wall thickness?

At the design stages of the pipeline, it is necessary to determine the diameter of the structures in individual sections. For this, a special hydraulic calculation is used, which helps to save on the purchase. As a result of the calculations, the pressure and configuration of the line are taken into account. Increased parameters will not harm, but will affect the increase in the level of costs. If the diameter is too small, the pressure will be weak.

The diameters of the PP pipes vary between 1.6 - 120 cm:

For laying water pipes and heating residential premises, structures with a parameter from 1.6 to 3.2 cm are used.
For laying the internal sewer system - 4 and 5 cm or 11 cm.
The maximum dimensions of PP pipes are relevant when placing an external sewer line in multi-storey buildings.
When developing an internal water main, the length of the main and the number of points for water supply are taken into account. The supply pipe has a diameter of 3.2 cm; for wiring in buildings, the external section of the PP pipes is 1.6 - 2 cm.

Separately, the wall thickness, which affects the inner diameter of polypropylene pipes for heating, is taken into account. A table with markings for household products (section from 16 to 110 mm) will allow you to determine the dependence of the parameters:

How to determine permeability?

For the correct calculation of the passability, the external section is not taken into account. When calculating the internal section, it is necessary to know how much liquid is transported in a certain period of time.

Factors affecting patency:

Inner diameter (small section affects the increase in wall resistance and slowing down the flow).
pressure on the walls.
The length of the line (as the length increases, friction increases, reducing the flow rate).
Material (smooth inner coating affects the increase in transport speed).
Duration of operation, which allows you to determine the amount of deposits.
The number of transitions from one section to another and turns.

For a home highway, a simple formula for calculating the patency of a pipeline is used:

Where Q is the calculated level of load on the section of the highway,

V is the speed of water transportation in the pipeline.

Δt is the difference in water heating during supply and return.

There is another formula:

The calculations are based on the total amount of fluid Q and its movement velocity V. To determine the latter parameter, indicators of 1.5–2 m/s for pipes with thick walls and 0.7–1.2 m/s for pipes with thin walls are used. . Since PP has a smooth inner coating, the highest liquid transport rates are used in the calculations. This minimizes friction losses. More accurate calculations are made in multi-storey buildings. When arranging risers, the internal section is often selected within 3.2 cm.

Section matching:

For an external section of 1.6 cm, an internal diameter of 1 cm corresponds.
For an external section of 2 cm, a pipeline with an internal diameter of 1.5 cm will be the best solution.
For external parameters of 6.3 cm, pipes of 5 cm (inside the structure) are well suited.
With external dimensions of 12.5 cm, the internal dimension is 10 cm.

Large pipes are used for cold water supply and external sewage system (their laying for hot water supply is not allowed). To supply water to the entire microdistrict, PP pipes with a cross section of 50 cm or more are used.

For small houses and apartments, a minimum number of parsing points is required, which eliminates the need to calculate the exact dimensions of polypropylene pipes in mm.

The section table of the contours is used taking into account the reserve of the diameter of the pipes, relative to the mixer:

When arranging household communications, it is enough to purchase PP pipes for heating with a cross section of 2 cm.
To supply cold water, lines with a diameter of 1.6 cm are used.
A large diameter (from 50 cm) is not required at all.

Dependence of pipe size on material

Based on the technical characteristics of the material, the following types of pipeline are distinguished:

PPR (PPRS, PPR) - for the manufacture of pipes, a static copolymer of foamed propylene (or a random copolymer) with a crystallized molecular composition is used. They well withstand a wide range of heating / supercooling from -165 to +1410 C and shock loads. This determines their widespread use for drainage or heating systems in the domestic sector. Their parameters vary in the range of 1.6 ... 11 cm and are selected taking into account the pressure for which they are designed.
PPH. Polypropylene pipes are created using modified components: antistatic agents, flame retardants and nucleators, which give a high level of impact strength to the polymer. The structures are used for external water supply, ventilation and sewerage systems. They exclude the possibility of laying a heating main, which is explained by the low melting point. The large section of PPH pipes ensures their use in an industrial drainage system.
PPB (linear copolymer). According to its structural properties, this raw material is characterized by the presence of microscopic homopolymer molecules (blocks) of different structure and composition, alternating in a given order. Due to the peculiarities of the molecular structure, these pipes have high impact resistance and are well used when laying the "warm floor" system or supplying cold water to the house.
PPs (semi-crystalline engineering polymer) is a material with a special molecular composition. Possesses high resistance to mechanical and thermal loadings, wear. The cross section of pipes varies in the range of 2 - 120 cm. Their laying is recommended for ventilation and heating systems, as well as water supply.

Pipe welding

The heating of the welding machine for PP pipes is 250-260 C. After reaching the set temperature (for 10-15 minutes), two elements are prepared for connection and at the same time the contours are placed on the welding nozzles. Gradually, without turning, they are pressed into the nozzles of the soldering iron to the mark of the specified welding depth. From this moment, you can start counting the duration of warm-up. Upon completion of the process, remove the products from the heating parts immediately, without turning, and make the connection to the previously marked depth.

It is not recommended to push the contour into the fitting very deeply, which will affect the blocking of the water flow. When fusing parts, rigid fixation or adjustment of the connection is required. At the end of the melting of the elements, it is necessary to allow the joint to cool, which forms a monolithic structure of the plumbing or heating system. The welding time, based on the cross section and the depth of thermal exposure, is indicated in the tabular data:

How much do domestic pipes cost?

The cost of pipes with a large cross section

According to GOST 18599-2001, the use of PP mains is allowed when installing or changing a water supply system, arranging automatic irrigation, a pool or raising water from an artesian source. HDPE pipes are used for laying in straight sections of 120 cm and bays of 1000, 2000 cm. They are characterized by a smooth inner and outer coating. The SNiP rules allow the presence of defects within tolerances, exclude the possibility of the formation of bubbles or cracks, third-party inclusions.

Pipes with a large diameter are classified on the basis of regulated parameters that determine their purpose.

Marking of polyethylene pipes: PE80 and PE100. The first option is characterized by excellent consumer properties for a small size line (up to 90 mm). Marking PE100 determines significant savings on material when laying a pipeline with a large cross section. Separately, the indicator of resistance of the HDPE line to pressure on the walls (SDR) is taken into account, it is calculated by a simple ratio of the cross section of PE pipes to the thickness of the partitions. Along with a decrease in the obtained value, the strength index increases.