Flanges from steel pipe to polyethylene. Flanges for pnd pipes. The technology of connecting plastic pipes with metal

Modern plumbing is rarely made of metal. He has worthy competitors - polymers, which are gradually replacing him in many areas. One such material is low density polyethylene. Pipes for pressure pipelines are made from this material, that is, for water pipes and even for gas pipelines. This kind of material is becoming more and more popular as the connection polyethylene pipes easy to do by hand. You just have to follow very simple rules.

Advantages and features of the application

Polyethylene pipes are made from low pressure polyethylene. This material is abbreviated as HDPE. It is characterized by increased strength and elasticity, has good performance properties:

chemically neutral, can be used for food transportation;
smooth walls prevent the formation of plaque inside;
not subject to corrosion;
low coefficient of thermal expansion - about 3% at maximum heating (up to + 70 ° C);
they normally react to the freezing of water inside, due to elasticity they increase in diameter, and after thawing they take on their original dimensions.

One moment to remember! If you need pipes resistant to freezing (for example, for), when choosing, look at the description or specifications. Not all types of copolymers that are used for the production of pipes tolerate freezing well. So be careful.

The main disadvantage of polyethylene pipes is the restrictions on the temperature of the transported medium: it should not be higher than + 40 ° C, that is, only cold water supply can be made from HDPE, for hot water and, moreover, they cannot be used for heating.

Another point: polyethylene does not tolerate UV radiation. With constant exposure to the sun, the material loses its elasticity, and, after a while, breaks (some manufacturers make HDPE pipes resistant to ultraviolet radiation, but they are more expensive). Because the open laying of the water supply from plastic pipes very undesirable. But to lay a pipe in a trench from a well or a well to a house, make a wiring cold water around the house is very possible. This is a fairly economical and convenient solution, since the installation and connection of polyethylene pipes is not a very complicated matter. If we are talking about a detachable connection, then no equipment is needed for it. All you need is fittings and hands.

Which polyethylene pipes are better

For production water pipes polyethylene of two grades is used - PE 80 and PE 100. The hundredth polyethylene is denser and more durable than the eightieth. For water supply systems of a private house, the strength of PE 80 is more than enough - they can withstand pressure up to 8 atm. If you like a large margin of safety, you can take them from PE100. They work fine even at 10 atm.

What you should pay attention to - the country in which it is produced this product. Quality leaders are European manufacturers. High precision execution guarantees high reliability of the system. Average quality and prices are from Turkish companies, in a cheaper price segment, Chinese manufacturers. Their quality, as usual, is also much lower. It is difficult to give advice here, everyone selects at their own discretion (or what is in the region).

Types of HDPE pipe connections

There are several types of connection of polyethylene pipes:

detachable (on fittings or couplings);
one-piece - by welding:
- using a special welding machine;
- electrical couplings - a heater is built into such couplings when it is supplied electricity, polyethylene heats up and fuses.

Weld mainly pipes of large diameters, which are used to create main pipelines. Pipes of small diameters - up to 110 mm, used in private construction, are mostly connected using fittings. Couplings are used more often when repair work because they take longer to install.

Fittings for polyethylene pipes are shaped parts (tees, crosses, angles, adapters, couplings), with the help of which the required system configuration is created. Since self-connection of polyethylene pipes is carried out more often with the help of fittings, let's talk about them in more detail.

Assembly on compression (crimp) fittings

On one or two sides of the fitting (sometimes on three), a whole system is installed that provides the connection. The fitting itself consists of:

How reliable is the connection

Despite the apparent unreliability, the connection of polyethylene pipes on compression fittings is reliable. Done right, it endures operating pressure up to 10 atm and above (if these are products of a normal manufacturer). Watch the video for proof.

This system is good with ease self-assembly. You probably appreciated it already from the video. Just the pipe is inserted, the thread is tightened.

Summer residents, in addition to the ability to do everything with their own urks, like it because, if necessary, everything can be disassembled, hidden for the winter, and reassembled in the spring. This is in case the wiring is done for irrigation. The collapsible system is also good because you can always tighten the digging fitting or replace it with a new one. The disadvantage is that fittings are bulky and internal wiring in a house or apartment is rarely made of them - appearance not the most pleasant. But for the plumbing section - - better material hard to find.

Assembly order

The pipe is cut strictly at 90 °. The cut should be even, without burrs. Dirt, oils or other contaminants are also unacceptable. Before assembly, chamfers are removed from the sections of the connected sections. This is necessary so that the sharp edge of the polyethylene does not damage the sealing rubber ring.

During installation, the connection of polyethylene pipes on compression fittings tighten by hand

Spare parts are put on the prepared pipe in this order: a compression nut is pulled, then a collet, followed by a thrust ring. rubber gasket installed in the fitting body. Now we connect the body and the pipe with the parts put on it, applying force - we must insert it all the way. We tighten all the spare parts to the body and connect them with a crimp nut. We twist the resulting connection of polyethylene pipes with force by hand. For reliability, you can hold out with a special mounting key. The use of other tightening tools is undesirable: plastic can be damaged.

Saddles and their scope

In addition to fittings, there is another interesting device that allows you to make branches from an already finished pipeline. These saddles are specially designed couplings. This coupling has one or more threaded holes. A crane is usually placed in them, and a new branch plumbing.

Sedeki are put on the pipe, fixed with screws. After that, a hole is drilled in the branch with a drill and a thick drill in the surface of the pipe. When it is ready, a crane is installed, a branch is assembled further. So improve the system with minimal effort and cost.

Flange connections and transition to metal

In the water supply system, elements of the system that do not have a threaded, but a flanged connection can be installed. Usually these are taps or other shut-off or control valves. To connect with such elements, there is a special fitting for HDPE. On the one hand there is a standard compression version, on the other - a flanged version. Installation is standard - with a compression nut on one side, gaskets and bolts on the flange side.

When installing a water supply system from polyethylene pipes, questions may also arise about the connection of polyethylene and metal. For these cases, fittings are used, on one side of which there is a thread. It can be external or internal - it depends on the type of device or transition being installed. Such fittings are available in straight lines, in the form of a 90° angle.

The installation is standard - a thread (with winding neatly) on one side and a crimp nut on the other.

When arranging modern systems sewerage, heating, water supply, polyethylene pipes are often connected with fittings. Also, when laying household communications, flanges are used to assemble tubular products from different materials.

Pipes made of polyethylene (PE) in last years are actively replacing traditional cast iron and steel products from the construction market. Plastic structures are superior to metal ones in a number of indicators. Therefore, such a process has a completely logical explanation - everyone wants to have in their home reliable in operation and inexpensive in cost, heating, sewage, assembled without welding. When installing, you have to face one problem. It lies in the fact that many elements of household pipelines in apartments are made of metal products.

Connection of plastic and metal pipes

And here it is important to correctly connect PE pipes with steel (cast iron). This can be done in two ways: using flanges and using fittings. flange connection polyethylene (polypropylene) pipes with steel pipes are recommended for cases where systems of products with a cross section of more than 50 mm are being equipped. But pipelines with a diameter of up to 50 mm are best connected with fittings. They are special elements with a smooth socket for connecting PE pipes and a thread for metal pipes.

The flange is made in the form of a threaded part. It is most often used to connect metal and polyethylene water pipes, as well as gas communications without welding. Flanges for assembling household networks from different materials have not only a thread on one side, but also a mandatory seal. The latter is located at the second end of the described element. The seal guarantees a tight and truly durable connection, which, if necessary, can always be disassembled.

Flanged connection example

For laying communications, you can use:

metal cap flanges;
flanges for special bushings (they are called collars).

Experts advise home craftsmen to connect PE pipes along the second of these methods. In this case, the connection is obtained with the highest quality. Flanges for bushings are made of steel 20. Flanges for polyethylene pipes are designed for operating pressures up to 1.6 MPa. These details are made with a section from 20 to 1200 mm. Therefore, problems with the selection of suitable elements for creating detachable connections never arise. There are several subtleties of assembling communications using flanges. We present them below:

flanges based on cone-type bushings must be used when working with pipes with a cross section of more than 200 mm;
light PE pipe products with a diameter of 150–300 mm, as well as heavy ones with a cross section of less than 150 mm, are best connected using flanges with a straight shoulder;
to increase the strength characteristics of the connection of pipes from different materials, you can use straight-shaped bushings with a special conical transition.

When choosing flanges for making detachable connections, please refer to Special attention on the quality of fasteners. They are not allowed to have burrs and sharp edges. Such defects can cause damage to PE pipes. The flange connection of polyethylene pipes with a cross section of more than 50 mm is made according to a simple scheme. You need to exactly cut the tubular product in the place where it will dock with another part of the communication. After that, you carefully pull the flange onto the pipe and put a rubber gasket on top.

Such a sealing element can go beyond the cut made by a maximum of 1 cm, no more. Then you push the flange onto the gasket and mate it (using bolts) with the counter flange. Bolts must be tightened very carefully. If you apply excessive force during this procedure, the polyethylene pipe may crack.

Individual elements of communications (heating, water supply) in an apartment or house are often connected with fittings. These elements are indispensable for connecting polyethylene tubular products to metal filters, meters, mixers, pipes and other parts of a modern pipeline. Fittings are either external or internal threaded. Structurally, they, as noted above, are special adapters with a thread and a coupling.

Fittings for connecting pipes

When choosing fittings, consider the diameter metal pipe into which they will be cut.

Adapters are ideal when the pipeline has a lot of bends and turns. The assembly of the system (steel or cast iron pipes plus polyethylene) using fittings is performed as follows:

Unscrew the coupling of the metal tubular product. If the junction of PE and steel pipe falls on a different site, you will need to cut off the old metal product. And then you need to lubricate the cut edge with oil or grease and use a thread cutter to make a new thread for the fitting. The operation for a more or less experienced self-taught craftsman is simple.
Carefully wipe the thread on the pipe, wrap it with fum tape or ordinary tow. After that, apply silicone on top. Tape or tow is wound quite a bit. It is enough to perform a couple of turns. In this case, the edge of the wound material when clamping it must necessarily be directed along the thread.
With your hands (do not use a wrench or other tool), gently wind connecting fitting for carving. With strong pressure on the adapter, there is a high probability of cracking it.
Insert the PE pipe into the coupling at the second end of the fitting and solder it.
Treat the connection with a sealant.

Basically, everything. You have completed the connection of a polyethylene (or polypropylene) pipe with steel. Turn on the water (if a water supply system was made) and check the fitting attachment for leaks. If there is one, simply twist the adapter a little. The final work is the sealant treatment of the connection made. You can fully use the pipeline in 3-4 hours. During this time, the sealant will dry completely.

Flange adapter - a special device for creating a tight connection in pipelines. The part performs the function of an adapter for a strong joint of pipeline parts or a flange for connecting shut-off and control valves and other parts of the system. The flange adapter for polyethylene pipes differs from other varieties in the restrictions on temperature indicators and pressure indicators in the system, and also cannot be used in lines with an aggressive working environment.

The design is a device consisting of a coupling and a flange. It is necessary to use bolts to connect the adapter to the pipeline flange, and the coupling to the smooth end of the pipe.

When the bolts are tightened, the clamping rings move towards each other, the seal is deformed, tightly pressing against the outer surface of the pipe, thereby creating a strong articulation of the pipeline parts.

Advantages and disadvantages of the device

The adapter acts as a compensator for compression and tension of the axis and smooths out minor deviations from the initial design in the process. installation work and operation.

The detail allows you to install pipes made of polyethylene and polyvinyl chloride in a metal line. The device is resistant to vibrations, elevated temperatures and pressure surges.

Thanks to the gasket seal, the part can be used, among other things, in systems with an aggressive working environment.

To make the connection, no special tools are required, except for a wrench, and no special skills and abilities, which saves both time and money.

Note! The only drawback is that, due to too much clamping, over time, the gasket that provides a snug fit is destroyed.

Types of adapters and scope

The flange adapter is used in shipbuilding, automotive, construction and housing, oil and gas applications.

There are several types of flange adapters:

adapter for cast iron pipes;
for installation of PVC pipes;
for PE pipelines;
for AVK (applies to both PE and PVC pipes products).

Note! The device for pipes made of polyethylene is used only in systems operating at standard pressures and a limiting temperature of 700 C only for transporting water and other neutral liquids.

Flange adapter for PE pipes: technical data

The adapter for PE pipes is distinguished by an epoxy coating, which is applied by electrostatic method.

Clamping flanges are ordinary flat fastening rings (HDPE flanges), manufactured in accordance with GOST 12820-80, the inner diameter of which is bored to the required size. Mounting holes are evenly spaced around the circumference of the flange. Clamping flanges are mainly used in polyethylene (PE) pipelines, where they are used to connect HDPE pipes to each other, as well as to attach polymer pipes to metal pipes, to connect pipes industrial equipment, stop valves, etc.

Initially, all clamping flanges are made according to a single standard, but then they are bored, acquiring a different inner diameter. Value required diameter is determined depending on the dimensions of the polyethylene sleeve that will be used with this flange. The bored flange is put on the sleeve, the end of which is welded to the end of the pipe. Mounting carried out in this way makes it possible to achieve particularly high strength connections. At the same time, the flange is ideally attached to a pipe of any size, and all its other parameters - the number of holes and their diameter, center distance - fully correspond to flat welded flanges made in accordance with GOST 12820-80. Clamping boring flanges for HDPE pipes are of several types - for pipes with a maximum working pressure of 6, 10, 16 and 25 atmospheres. Clamping flanges presented in our catalog are made of high-quality steel grade CT20 (steel 20) with an anti-corrosion coating applied to it, which ensures the durability of products and resistance to environmental influences.

All flanges from the price list IN STOCK on our !

Price list "Clamping flanges for polyethylene (PE) pipes Ru 10"

vendor code	Pipe diameter, mm	DN mm	D mm	D0 mm	b mm	n pcs.	d mm	Weight, kg	Price per piece RUB, incl. VAT
FPND10050	50	40	145	62	12	4	18	1,175	277	To order
FPND10063	63	50	160	78	12	4	18	1,348	318	To order
FPND10090	90	80	195	108	14	4	18	2,163	510	To order
FPND10110	110	100	215	128	15	8	18	2,52	594	To order
FPND10160	160	150	280	178	17	8	22	4,49	1 059	To order
FPND10200	200	200	335	225	17	8	22	6,05	1 642	To order
FPND10225	225	200	335	238	17	8	22	5,42		To order
FPND10250	250	250	390	273	18	12	22	7,96	2 067	To order
FPND10280	280	250	390	294	18	12	22	6,64	1 881	To order
FPND10315	315	300	440	338	19	12	22	8,616		To order
FPND10355	355	350	500	376	19	16	22	11,817		To order
FPND10400	400	400	565	430	21	16	26	15,991		To order
FPND10560	560	600	780	613	22	20	30	29,112	6 870	To order
FPND10630	630	600	780	643	22	20	30	24,001	6 796	To order

When installing a line made of PE, for joining them together or for installing fittings, flanges for polyethylene pipes are used.

This part is able to provide the most reliable, durable and tight flange connection.

Article content

Part features

The fixing fitting for PE and PVC pipes is a flat disc with equidistant bolt holes. This product is installed together with a collar or sleeve.

Product types

The main parameters by which flange products for PE and PVC pipes are characterized are the inner diameter, outer dimensions, weight and working pressure.

Depending on what tasks these parts perform, There are the following types of adapters:

adapter with special welded bushings;

cap metal flange;

flange adapter free type, based on a straight or tapered shoulder.

The best way to connect light and medium PE pipes with a diameter of not more than 150 mm and light pipes with a diameter of up to 300 mm is a loose flange resting on a straight shoulder. A free flange with a tapered shoulder is used for fittings having a diameter of more than 200 mm.

Characteristics of the fixing flange for polyethylene pipes (video)

Advantages and disadvantages of a flange for PE and PVC pipes

Clamped steel loose flange adapter has a number of advantages over other parts, which makes it more popular to use. The main ones are as follows:

The adapter allows you to install PE in a metal line, it also makes the repair of such systems more affordable.

To mount the flange, there is no need to use any special tools and spend a lot of time: wrench and small skills allow you to install the part without any problems.

Also, the clamping flange adapter has the ability to compensate for the process of compression and extension of the axis, and this is simplifies the process of installation and operation, and reduce installation time.

As for the disadvantages, the most significant is the fact that the gasket is destroyed, providing a tight fit. This is due to the fact that they are clamped as hard as possible, and this leads to an excess of the tensile strength of the material.

Structurally, the most unsuccessful in this regard, since it cannot protect the gasket from deformation.

Those models of products in which gaskets are provided in some recesses are considered more protected from gasket rupture, however, they do not provide full protection, especially with a long service life of the part.

When installing the flange, take into account the fact that Under the influence of heat, the metal can expand. This causes the fasteners to elongate more than the adapter itself, and this can break the tight flange connection.