Flange connection of polyethylene pipes with steel pipes, transition from HDPE to metal. Connection of plastic pipes to metal Types of HDPE pipe connections
Modern plumbing is rarely made of metal. Worthy competitors have appeared for him - polymers, which are gradually replacing him in many areas. One of these materials is polyethylene. low pressure... This material is used to make pipes for pressure pipelines, that is, for water pipes and even for gas pipelines. This type of material is becoming more and more popular, since the connection polyethylene pipes easy to do with your own hands. You just need to follow very simple rules.
Advantages and features of the application
Polyethylene pipes are made from low pressure polyethylene. Abbreviated this material is labeled as HDPE. It is distinguished by increased strength and elasticity, has good performance properties:
- chemically neutral, can be used for transporting food products;
- smooth walls prevent the formation of plaque inside;
- does not corrode;
- small coefficient of thermal expansion - about 3% at maximum heating (up to + 70 ° C);
- They normally react to freezing of water inside, due to elasticity, they increase in diameter, and after thawing they take on their original dimensions.
One point to remember! If you need pipes that are resistant to freezing (for example, for), when choosing, look at the description or specifications... Not all types of copolymers used to make pipes are freeze-resistant. So be careful.
The main disadvantage of polyethylene pipes is 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 well. With constant exposure to the sun, the material loses its elasticity, and, after a while, breaks down (some manufacturers make HDPE pipes resistant to ultraviolet radiation, but they are more expensive). That's why open gasket plumbing from plastic pipes very undesirable. But it is very possible to lay a pipe in a trench from a well or a well to a house, to make cold water distribution around the house. It is quite economical and convenient solution, since the installation and connection of polyethylene pipes is not very difficult. If we are talking about a detachable connection, then no equipment is needed for it. Only fittings and arms are needed.
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 stronger than the eightieth. For water supply systems of a private house, the strength of PE 80 is more than enough - they can withstand pressures up to 8 atm. If you like a large margin of safety, you can take them from the PE100. They work normally even at 10 atm.
What you should pay attention to is the country in which this product is produced. Quality leaders are European manufacturers. High precision of execution guarantees high reliability of the system. Average quality and prices are for Turkish companies, in a cheaper price segment are Chinese manufacturers. Their quality, as usual, is also much lower. It is difficult to give advice here, everyone chooses 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;
- electric couplings - a heater is built into such couplings, when an electric current is applied to it, the polyethylene is heated and fused.
Mainly pipes are welded large diameters, which are used to create trunk pipelines. Small diameter pipes - up to 110 mm, used in private construction, are mostly connected using fittings. Couplings are used more often when repair work as 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 the independent 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
A whole system is installed on one or two sides of the fitting (sometimes on three), which ensures the connection. The fitting itself consists of:
How reliable is the connection
Despite the seeming unreliability, the connection of polyethylene pipes on compression fittings reliably. Done correctly, it can withstand operating pressures of up to 10 atm and higher (if these are products of a normal manufacturer). To prove it, watch the video.
Good this system ease self-assembly... You probably already appreciated this from the video. The pipe is simply inserted, the thread tightened.
Summer residents, besides the opportunity to do everything with their own lessons, she likes the fact that, if necessary, everything can be disassembled, hidden for the winter, and reassembled in the spring. This is in case the layout is made for watering. The collapsible system is also good in that you can always tighten the underfloor fitting or replace it with a new one. Disadvantage - fittings are bulky and internal wiring in a house or apartment is rarely made of them - appearance not the most pleasant one. But for the water supply section - - better material hard to find.
Assembly order
The pipe is cut strictly at 90 °. The cut should be even, without burrs. Also, the presence of dirt, oils or other contaminants is unacceptable. Before assembly, the chamfer is removed from the sections of the sections to be connected. This is to ensure that the sharp edge of the polyethylene does not damage the sealing rubber ring.
During installation, the connection of polyethylene pipes on crimp fittings is tightened by hand
The spare parts are put on the prepared pipe in this order: the crimp nut is pulled, then the collet, followed by the thrust ring. Install the rubber gasket into 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 parts to the body and connect with the crimp nut. We twist the resulting connection of polyethylene pipes with effort by hand. For reliability, you can tighten it with a special assembly key. The use of other tools for tightening is undesirable: you can damage the plastic.
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.
Zedeks are put on the pipe and 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, the branch is going further. This is how the system is improved with minimal effort and expense.
Flange connections and transition to metal
In the water supply system elements can be installed that have not threaded, but flange connection... Usually these are taps or other shut-off or control valves. For connection with such elements, there is a special fitting for HDPE. On one side there is a standard compression version, on the other - a flanged version. Installation is standard with a crimp 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 that have threads on one side. It can be external or internal - it depends on the type of installed device or transition. Such fittings are straight, there are in the form of an angle of 90 °.
The installation is standard - a thread (with winding neatly) on one side and a crimp nut on the other.
A flange adapter is a special device for creating a tight connection in pipelines. The part serves as 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. A flange adapter for polyethylene pipes differs from other varieties in restrictions on temperature indicators and indicators of pressure 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 plain end of the pipe.
When the bolts are tightened, the pressure rings move towards each other, the seal deforms, pressing tightly against the outer surface of the pipe, thereby creating a strong joint between the parts of the pipeline.
Advantages and disadvantages of the device
The adapter acts as a compensator for compression and extension of the axle and smooths out minor deviations from the initial design in the process installation works and operation.
The part allows you to install pipes made of polyethylene and polyvinyl chloride in a metal line. The device is resistant to vibrations, high temperatures and pressure surges.
Thanks to the gasket, the part can be used, among other things, in systems with an aggressive working environment.
No special tools are required to complete the connection, except a wrench, and no special skills and abilities, which saves both time and money.
Note! The only drawback is that over time, the gasket that provides a snug fit breaks down due to too strong a grip.
Types of adapters and scope
The flange adapter is used in the shipbuilding, automotive, construction and residential, oil and gas industries.
There are several types of flange adapters:
- adapter for cast iron pipes;
- for the installation of PVC pipes;
- for PE pipelines;
- for AVK (applies to both PE and PVC pipes products).
Note! The device for polyethylene pipes is used only in systems operating at standard pressures and a maximum 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 epoxy coated, which is applied electrostatically.
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. The mounting holes are evenly spaced around the circumference of the flange. The main application of clamping flanges is found in polyethylene (PE) pipelines, where they are used to connect HDPE pipes to each other, as well as to connect polymer pipes to metal pipes, connect to industrial equipment pipes, valves, etc.
Initially, all clamping flanges are made according to the same standard, but then they are bored, acquiring a different inner diameter. The size of the required diameter is determined depending on the size of the polyethylene sleeve that will be used with this flange. The bored flange is pushed onto a sleeve, the end of which is welded to the end of the pipe. Installation carried out in this way allows a particularly high strength of the joints to be achieved. In this case, the flange is ideally connected to a pipe of any size, and all its other parameters - the number of holes and their diameter, the center-to-center distance - fully correspond to flat welded flanges made in accordance with GOST 12820-80. Clamp boring flanges for HDPE pipes are of several types - for pipes with a maximum working pressure of 6, 10, 16 and 25 atmospheres. The 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 the products and resistance to the external environment.
All flanges from the price list IN STOCK on our !
Price list "Clamping flanges for polyethylene (PE) pipes PN 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 PE line, for joining them together or for installing fittings, flanges for polyethylene pipes are used.
This part is capable of providing the most reliable, strong and tight flange connection.
Content of the article
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 bushing.
Types of products
The main parameters by which flanged 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 sleeves;
- metal flange;
- loose flange adapter supported on straight or tapered shoulder.
The best way to connect light and medium PE pipes up to 150 mm in diameter and light pipes up to 300 mm in diameter is with a loose flange resting on a straight collar. A loose flange with a tapered shoulder is used for fittings with 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
The clamp-on 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 and into a metal line, this also makes the repair of such systems more affordable.
- To mount the flange, there is no need to use any special tools and waste 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 expansion of the axle and this is makes it easier to install and operate, and reduce installation time.
As for the disadvantages, the most significant is the fact that the gasket is destroyed, which ensures a tight fit. This is due to the fact that they are clamped as tightly as possible, and this leads to exceeding the ultimate 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 rupture of the gasket, 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 metal can expand under the influence of heat. This causes the fasteners to elongate more than the adapter itself, and this can compromise the tight flange connection.
IN recent times very often, when arranging various water supply and heating systems, it is required to connect plastic pipes with metal ones. To solve the problem of installing pipes from various materials, you can choose one of the options proposed in our article - a threaded or flange connection.
Connection types
There are two types of connections:
- Threaded connection. For the connection of polyethylene pipes with metal pipes, do not large diameter(up to 40 mm) it is best to use special fittings with a thread for metal pipe and a smooth sleeve for plastic.
Pro tip:
To reliably seal threaded connection metal part of the structure, use rolled linen fiber, as in the assembly of conventional steel pipes.
- Flange connection. For pipes of large diameter are used different types flanges, since it is difficult to imagine a thread on a pipe with a large diameter, for example 600 mm, that can be screwed in by hand.
We will look at a threaded connection using an example polypropylene pipes, and flanged - polyethylene, however, it is worth noting that each type of connection is suitable for both types of pipes.
Technology for joining plastic pipes with metal
Using threaded fittings
For the installation of polypropylene pipes with metal parts (pipes, mixers, meters, filters, etc.), fittings are used with a thread of the required diameter on one side and with a coupling for soldering a plastic pipe on the other. The thread on such fittings can be both internal and external.
Connection of steel and polypropylene pipes using fittings:
- Unscrew the coupling steel pipe where it is supposed to be connected to a plastic pipe, or cut off a part of the old metal pipe, and grease the edge with grease or oil and cut a new thread with a thread cutter.
- Wipe the thread, wind tow (or fum tape), lubricate with silicone. Make no more than one to two turns so that the edge of the tape is aligned with the thread when clamping.
- Screw on the press fitting without using a wrench to avoid cracking. If necessary (if water flows after it is turned on), tighten the fitting.
With the help of polypropylene fittings of various configurations, it is very convenient to make various kinds of bends and turns in the installed pipeline system. It is also possible to change the configuration of the fitting by heating it with construction hair dryer, but not more than 140 degrees. It should be remembered that polypropylene ignites when heated above 350 degrees, and you should not allow it to overheat.
Polypropylene pipes have properties to expand and contract when different temperatures... Therefore, when using them for heating or for supplying hot water, when installing pipes in the wall under a layer of plaster, you should leave a gap in the grooves of at least 1 cm using tubular insulation, especially around the contours, tees.
Using flanges
A quite often used detachable type of connection for polyethylene pipes is a flange connection. For its implementation, sleeves for flanges are used, welded to the ends of pipes, or flanges made of metal.
Installation of plastic pipes using flanges is used:
- for connecting polyethylene pipes with steel components of the system: pipes, pumps, valves;
- for the possibility of quick disassembly of the pipeline in case of need for cleaning or repair;
- when connecting large diameter pipes.
Loose flanges supported by collars are most suitable for plastic pipes. To make the connection of steel and polyethylene pipes,
free steel flanges are selected of such dimensions that correspond to the dimensions of the metal parts of the installed pipeline.
Pro tip:
Pay special attention to the absence of sharp elements and burrs on the metal flanges, which can damage the polyethylene pipe.
Some features of flange connections:
- for medium and heavy polyethylene pipes up to 150 mm in diameter and for light pipes up to 300 mm in diameter the most suitable option- use of free flanges resting on a straight shoulder;
- a straight collar with a tapered transition is used to increase the strength of the connection;
- free-type flanges supported on tapered collars are used to connect pipes with a diameter of more than 200 mm;
- A wedge connection with a shaped flange and a steel shoulder can be used for pipes of any diameter.
Work procedure:
- Cut the pipe at the joint. Make sure that the cut is even.
- Slide a free type metal flange onto the pipe.
- Put on the rubber gasket. Do not allow it to flow over the pipe cut by more than 10 mm.
- Slide the flange over the gasket, bolt to the counter flange.
Pro tip:
Tighten the bolts evenly using no more than the torque specified in the flange and accessory specifications.
As you can see from the instructions, both methods are quite simple to implement. The only condition for their performance is careful adherence to the description - then your pipeline will be of high quality and reliable.