Types of fittings for underfloor heating pipes, overview of manufacturers and installation procedure

The way we think about heating our homes has changed dramatically thanks to underfloor heating systems, which provide effective warmth and comfort without requiring large, unsightly radiators. The fittings for the underfloor heating pipes are a vital part of these systems. These fixtures are essential to making sure the system runs smoothly and effectively.

Regarding underfloor heating pipe fittings, there are numerous varieties on the market. Manufacturers provide a range of choices to accommodate various installation requirements and tastes. Bend supports, connectors, manifold adapters, and end caps are examples of common types. For the purpose of installing and maintaining the underfloor heating system, each type has a distinct purpose.

There are many different manufacturers of underfloor heating pipe fittings, and they all offer the market their own distinctive designs and technologies. Among the well-known producers are Emmeti, Rehau, Roth, and Uponor. These businesses are renowned for their creativity and dependability in creating premium fixtures that satisfy the exacting specifications of underfloor heating systems.

The process of installing underfloor heating pipe fittings usually consists of a few simple steps. First and foremost, it is imperative that the subfloor be properly prepared. In order to guarantee a level surface for the heating system, this also entails cleaning and leveling the area. For uniform heat distribution, the pipes must then be laid out in accordance with the floor plan and secured with the proper fittings.

An underfloor heating system’s overall performance and longevity depend on the pipes being connected correctly using fittings. To stop leaks, great care must be taken to make sure that all fittings are firmly fastened and sealed. Finally, before completing the floor covering, testing the system after installation guarantees everything is operating as it should.

A thorough understanding of the various fitting options, reliable industry manufacturers, and the installation procedure can help both professionals and homeowners make well-informed decisions when selecting and installing underfloor heating systems. Many find underfloor heating to be a desirable heating option because it can provide efficient, quiet, and comfortable warmth throughout the home with the right fittings and installation.

What is it?

The evolution of technical engineering plumbing is known as heated floor construction. The composition consists of sensors, various devices, and pipes. The creation of such a plan ought to be done with caution.

Generally speaking, fasteners, the connecting element in this type of wiring, allow for the certain and accurate collection of water when a pipeline is installed for either a warm or cold water supply. They are put in place at branching, turning, and diameter transitions. Transitional direct fasteners are used to join pipes with the same diameter while connecting conductors with varying diameters.

When a pipe’s direction, diameter, or branch needs to be changed, fittings are a necessary component of the pipeline. The definition of "fitting" in English is "to mount and collect."

A unique method is required here, as the warm floor is installed over a rough base and filled with mortar before a screed is created. This process is very different from assembling a traditional water supply system. As a result, fittings are viewed entirely differently.

Why are they needed?

The system is installed using a variety of components, but the fasteners play a role in the longevity of the internal wiring and the functionality of the essential components, in addition to the collectors, mixing unit, and pipeline contours.

Leaks result from improper or inadequate fixation. When the pipes for a water-heated floor that are installed in the screed sustain damage, such a need occurs. The coolant conductor may break if the installer unintentionally scratches the product.

Even though the installation was finished and the defect needed to be fixed, it’s possible that the master was unaware of it. The connections between pipes in heated floors are the same as those in a typical pipeline. The heating system fitting installation will go smoothly after correct joining, and the difference won’t even be apparent.

Is it possible to do without?

Originally, the engineering project for warm floors’ internal portion was intended to be a single, seamless structure. In this instance, the pipeline installation will be trustworthy. Internal connections increase the possibility of leaks and other unfavorable, unanticipated events.

Regardless of the systemic infraction, it frequently necessitates pipeline disassembly and intricate repair work. Leaks do not always result from the installation of fittings as connecting elements, if that is necessary. There is less faith in such an installation’s dependability.

Plumbing experts thus attempt to install a sturdy pipeline devoid of joints. Fittings are optional in situations where joints are not required if pipe strength, flexibility, and quality permit it.

Device and design

Heating floor contours are created using a variety of materials, including polypropylene pipes and metal-plastic composites. When installing pipelines and fittings, experts follow a single guideline: the materials should match or be compatible with one another.

• Fittings for plastic pipes, regardless of the type of connection, rotary or for branching, consist of a polymer base, parts that provide threaded fixation. Elements that are soldered are cast as one piece. Connecting parts include compression couplings, when pipe blanks require mechanical compression of metal walls. Such a product is a linear coupling, where on one side there is a polypropylene insert for a soldered connection. On the opposite side, fastening is carried out with a metal nipple. It is installed in a plastic pipe, the compression nut is used to tighten the joints.
• The same principle of the device is used for compression couplings designed to connect a pipeline, for the manufacture of which cross-linked polypropylene, polyethylene, plastic were used.
• When a metal-plastic pipeline is laid in the heating system for connections, connections of shut-off valves, plastic fittings are used for polypropylene lines, which have a metal conical nipple and a union nut with a gasket.
• The nipple has an external socket built in, the fitting compresses the edge of the metal-plastic pipe. To prevent the plastic section soldered on the back side from turning, the coupling body is made in the form of a hexagon for a key.
• If pipe blanks are connected with couplings cast from cross-linked polyethylene or polypropylene, they consist of a cast body with 2 annular grooves at the ends.

A classic barrel is used for connection, as well as fittings of different diameters, adapters for internal soldering of pipe fragments. A plastic element can be cast in the form of a corner, a cross, a bypass to overcome obstacles. Assembly of cast fittings is carried out by soldering, PVC couplings are joined to the pipeline using adhesive.
Fasteners not only join pipe sections, they are used to connect the pipeline to heating or pumping equipment.
Such a polypropylene adapter has a groove for soldering on one side, and a nipple, a union threaded nut on the other. When the technical conditions require a threaded connection, select a coupling with a thread. It consists of an element of 2 halves, where the outer and internal threads are cut, inside the structure is a pressed plastic liner.
When the compound is created to the output of the fitting, the mixer is connected with a flexible eyeliner, the withdrawal is performed with a plastic tee, where a lateral metal insert is adapted on a plastic base. In a complex device, a valve is built, a check valve for supplying a coolant.

In our comprehensive guide to underfloor heating systems, we cover top manufacturers in the field, go over different pipe fitting options, and walk you through the easy installation procedure. For effective heat distribution and long-term underfloor heating system performance, knowing the appropriate fittings is essential. Understanding how these parts function together can make all the difference in ensuring a cozy and economical heating solution for your house or project, whether you’re thinking about PEX or other materials.

Requirements and characteristics

If there are no joints in the contours of the docking units, the coolant in the warm floors should ideally flow throughout the entire line. If pipes are made from stitched propylene, then this type of installation is done. There will be connections when a small amount of polypropylene pipeline is laid, but fittings are necessary for metal-plastic pipes.

Simultaneously, compression or threaded fittings happen in distribution systems rather than beneath the floor finish. Compression fittings are not installed on polypropylene pipes because the presence of material in compressed regions violates the layered structure.

Press-fitting with a steel sleeve and pressing the element with a special tool is how the highway for coolant circulation in the warm floor system is installed. Five MPa of pressure is not beyond the capabilities of fasteners. Any kind of fitting for a pipeline should, in general, be made of the same material as the pipes and meet the following requirements:

• increased reliability;
• high strength to withstand the loads, temperature changes;
• ensure a sealed, inexplicable connection of pipes;
• should not subject the pipeline to deformations at the compression site;
• installed according to the installation method provided for this product.

As required by GOST 32415-2013, the manufacturer provides the parameters of the characteristics on the body of the fitting in the accompanying documents with regard to:

• name;
• designation;
• standard dimensional ratio between the outer diameter and wall thickness;
• nominal outer diameters of the joined fragments;
• thread sizes;
• operation class;
• nominal pressure that the element can withstand.

Fitting requirements are given with reference to:

• materials of manufacture;
• diameters of the joints;
• wall thickness.

Strength characteristics are significant indicators. It is not difficult to select equal sizes of inlet openings, but it is necessary to ensure that the 2 connected parts are resistant to the effect of pressure on the walls, this depends on their thickness. The fitting and the pipe must have the same ability to perceive internal and external loads.

Varieties

The fittings come in a variety of shapes in addition to sizes. The underfloor heating system uses a variety of elements for connections.

While all fasteners function according to the same principle, not all of them are. Pipes, which are manufactured from a variety of materials, including metal-plastic (Pex-Al-Pert) and cross-linked polyethylene (Pex), are used to install circuits in heated floors. A specific kind of fixing part is used for each type of pipeline.

Couplings

The simplest method for coupling any pipes together. They are made up of two pieces that have been twisted into a Eurocone. All that needs to be done is attach the coupling, enlarge the pipes’ interior diameter, and insert the element. The product is utilized in hot and cold heat supply systems and heating systems. The following characteristics of couplings:

• connection method – equal-pass, when conductors of the same cross-section are connected, and transitional, to join pipes of different diameters;
• thread locations – internal or external, the method of cutting threads allows you to connect pipeline elements of the same and different rigidity, connect flexible products;
• by manufacturing form – one-piece or detachable.

Using pipes and couplings from a direct manufacturer is advised. Polymer products consisting of cross-linked polyethylene are fitted with a sliding sleeve on a compression or connecting fitting. The connection is used in underfloor heating when monolithing a pipeline into a 3 cm thick concrete screed because it can withstand significant pressure.

When pouring with mortar, a pressure of three bar is applied to pipe connections. Through machine processing and hot stamping, a connecting fitting with a sliding sleeve is created. A sliding sleeve coupling cannot be separated. Tightness testing is done on products in accordance with SP 73.13302016.

Advantages:

• ensuring a strong connection of elements in the pipeline;
• long service life;
• withstand heating temperatures up to +90 0 C;
• use in cold and hot water supply, in a warm floor system.

Cons:

• intended use;
• violation of operating rules, installation instructions leads to leaks in the water-heated floor system due to non-hermetic connections.

Plugs

Plug-shaped components are intended to stop the coolant from circulating. External products are made with structural parts for soldering connections or covers for external fixation. They all have an internal thread. When it is intended to drain water from the system or when they decide to extend the circuit in the future, the plug is used for open ends in the pipeline.

Plugs for the underfloor heating system are fitted using the same material used to make the pipeline. High-pressure networks are fitted with robust polypropylene plugs. A threaded or welded connection is used during installation to guarantee the dependability of the underfloor heating circuits. PVC pipes are fitted with adhesive-fastened plugs. Benefits

• hermetic and easy installation;
• reliable cut-off of the coolant;
• high strength index when using a pipeline where a coolant circulates under pressure.

Drawbacks:

• it is necessary to accurately select a plug made of a material that is not capable of expanding under the influence of temperature;
• if the connection is adhesive or welded, it is not possible to dismantle the product, only by cutting it out of the pipe.

Nipples

Nipples are adapters that connect flexible wire to metal-plastic pipes. Union nuts are connected with elbows; threaded elbows are used to join pipes of various materials; elbows are also available for connecting a flexible hose to a polyethylene conductor. A union nut-equipped product is fitted onto a polypropylene pipe; a flange, functioning as a stop, is fastened to the end of the pipe. The plastic is drawn to the nut by the rotation of the thread. A sealing ring is installed to stop leaks. The fitting is securely fastened with a hexagon so that it can bear pressure.

Polypropylene pipes are fitted with union nipples, which have a union nut on top and a flange at the end. Instead of being pressed in, the metal is placed on top of the pipes. Sealing is ensured by a rubber seal.

Advantages:

• an excellent adapter allows you to connect pipes made of different materials;
• tight sealing;
• simple installation;
• easy operation.

Cons:

• the efficiency of connections is achieved mainly on straight sections of the pipeline;
• it is necessary to accurately calculate the dimensional parameters.

Crosses and tees

You can perform a tie-in from four pipes by fitting in the form of a cross. Socket welding is used for installation. Four pipes, arranged in a plane at 90 degrees, are present in a standard product.

The flows are also distributed to four sides in a monolithic body with the aid of a coplanar crosspiece. The coolant does not mix; instead, it passes one channel above the other only where they intersect. Because of the protruding walls’ increased internal diameter in this instance, there is no decrease in throughput. Four pipes make up the design of a two-plane crosspiece. One is in the other plane, and the other three are in the first. The pipe is distributed in the opposite direction using the outlet.

Tees are no less convenient for connections when branching a PVC pipe. A tee is used if horizontal distribution from a vertical riser is needed, when connecting radiators to underfloor heating.
Elements are produced with external and internal threads, for connection they are equipped with a metal part with thread cutting, a steel fragment is pressed into the tee.
There are plastic pipes, where one is a large diameter, 2 others are smaller. Such a design is effective for providing a certain level of throughput when it is necessary to narrow or reduce water flows in the system when branching.
Two-plane tees direct flows along planes. Such fittings are useful in the layout of a pipeline with angles, when laying a horizontal strip with turns and performing a layout with an outlet to the radiator.

Advantages:

• convenient layout;
• ensuring high throughput;
• easy installation;
• reliable connection.

Cons: Precise calculations are required to determine the proper connection.

Corners

Elbows are an essential component for connecting even the smallest pipe fragments, changing direction, attaching to additional equipment, and dividing flows. Plastic components with metal inserts are used. Elbows are fitted to convert between internal and external threads when joining pipes that are 90 degrees bent.

An angle with this bend direction is used when a bend at 45 0 is required. Use specialized welding to attach the plastic to the pipe. When connecting a conductor at a location quickly, these products enable you to avoid structural components along the pipeline route. advantages

• convenient distribution of the coolant, if it needs to be directed at a certain area at an angle;
• strength of connections;
• ensuring tightness.

Cons: It is challenging to choose the fitting for the necessary pipeline size.

Criterias of choice

A distinct range of end caps, polypropylene plugs, filters, valves, check valves, and other consumables are needed when installing heated floors. You must choose by determining the dimensions of the parts and the shape of the fittings. If not, you’ll need to buy an extra adapter to keep the system from becoming less functional.

The primary parameters consist of:

• the type of material that must be compatible;
• diameter of pipes and connecting element;
• Wall thickness.

It should be mentioned that the product’s marked end portion corresponds to the internal flow diameter measured in cast numbers. When determining the outer diameter of the pipe that has to be installed, this parameter can be used as a guide. To prevent issues at the connection point during joining, the fitting’s walls must be strong enough to support the pipe.

Strength, which represents the maximum pressure that a connected structure can bear, is directly correlated with wall thickness. The parameter was indicated in bars by the previous marking system. The new marking takes the shape of S or SDR symbols. The pressure is represented as a coefficient based on loads, and the letters show which series of pipes it corresponds to.

When marking, the standard dimensional ratio of diameter to wall thickness (SDR) indicates strength. The polypropylene pipe and the fitting flange must have the same designations; the numbers next to the classification indicate strength.

Best manufacturers

Numerous businesses have made the decision to focus on producing parts and fittings for water-heated floors.

RTP

Leading producer of heating system components, PE-RT, PVC, and polypropylene pipes and fittings. With 25 extrusion lines and 60 injection molding machines, the manufacturing company produces 1,500 items that are used for the installation of various systems, including water-heated floors, in its own modern factories.

For instance, "PP-R tee, polypropylene, PPR, RTP for pipes, (90 degrees), PN25, D20." When branching pipes at 90 0 is required for the installation of heated floors, a polypropylene tee is used in the hot and cold water supply. The product can withstand 25 bar of pressure and is made in compliance with GOST 32415-2013. Fits pipes with a diameter of 20 mm. A quick synopsis of the product

• type – connecting tee;
• applicable for pipes with a diameter of 20 mm;
• maximum operating temperature – 95 0 C;
• connection by soldering.

Aquatransit

A competitive business in the engineering plumbing, underfloor heating component, and fittings market. The business is at the forefront of the industry for the quality of its products. You can install heating systems with the help of pipes, fittings, and products from the Aquatransit enterprise. Direct manufacturer products are highly sought after and strike a balance between cost and excellence.

An illustration of this would be "Angle 90 ° Ø 25 mm PN25 (fitting connector) for Aquatransit polypropylene pipe" 05325 white." When setting up water-heated floors, the equal-bore polypropylene product is intended to connect the pipeline in the cold and hot water supply. When it’s necessary to reverse the direction of pipe laying, turn by 90 degrees, install the wiring intersection, or avoid right angles, the angle is utilized. Adequate attributes:

• in a package of 6 pcs.;
• pipe diameter 25 mm;
• color white;
• product type – connecting angle 90 0 ;
• soldered connection;
• working pressure – 25 atm.

Valfex

Russian engineering plumbing manufacturer Valfex is well-known throughout the world for the high caliber of its goods. The Valfex brand has made a name for itself as a provider of high-quality samples, underfloor heating components, and robust fittings. The business leads the industry in the quantity of polypropylene pipes and fasteners sold. As an illustration, consider this: "20×1/2′′ (150/30) union nut coupling (Valfex). The fitting’s purpose is to join pipes. The product is produced in compliance with TU 2248-001-21088915-2015 and GOST 32415-2013. Technical details:

• article 10139020;
• weight 0.050 g.;
• in a package of 30 pcs.;
• working temperature – 90 0 ;
• working pressure – 25 bar;
• material polypropylene/brass;
• branches with a diameter of 15 mm;
• connection with a diameter of 20 mm.

Kazan Pipe Plant

Makes bends, crosses, tees, plugs, bushings, and tee arrangements for underfloor heating systems. One illustration would be a polyethylene end element plug, which stops the coolant flow through the system. Plugs in the KTZ range come in the following forms:

• decorative;
• electrically welded;
• cast;
• compression.

"PPR plug with thread 1," for instance. Hermetically sealing a pipeline in areas where there are unutilized pipes, fittings, or valves with internal threads is accomplished with a polypropylene plug with thread. There are six wrench faces on the body.

Through threading and welding, the plug is attached to the pipe. The element is intended to function at a maximum working temperature of +95 0 C and a maximum working pressure of 25 atm.

REHAU

Provides fittings and items under the engineering plumbing category. The quality and variety of REHAU products are well known. "Fitting Nipple with internal thread G 3/4″ Universal series (12681431300) REHAU" is one example. The universal nipple is intended to be used as a transition piece between pipes in the underfloor heating system for both the water and heat supply. The housing is made of high-strength plastic, and trustworthy seals are present. A quick synopsis of the product

• fitting type nipple;
• diameter ¾;
• connection type threaded or with a quick-release nipple.

189 rubles is the product price.

Rules for use and installation

There are various methods for fixing fittings; the method of choice is determined by the connection element’s classification. There are two types of connection methods for product installation: detachable and non-detachable. Certain pipe types—like polypropylene—can only be installed with fittings that are fixed in place. Connecting elements of both types are used to join a polyvinyl chloride or polyethylene pipeline.

Installation process for various types of fittings:

1. Polypropylene couplings with thickened walls, connected to the pipe through a coupling connection. It is necessary to clean to absolute smoothness that part of the pipe that will enter the coupling, the fitting must be carried out to a complete stop, then remove, heat, insert, wait for a hermetic connection, fastening of the PP parts in the pipeline.
2. In a pipeline, when it is necessary to connect pipes of different sections, adapters are used, which act as a coupling, where the distinctive feature is a one-sided internal thread. The adapter is screwed on, creating a hermetic joint. Sealing of flat sections is carried out by joining through an adapter.
3. To install crosses with tees, shut-off valves are used, connected to a fitting that has a thread on one side, the second side is fastened by welding. For the procedure, it is necessary to monitor the temperature and heating time of polypropylene elements. It is necessary to strictly follow the installation rules. These include proper heating, cleaning, grinding of connecting pipes and fittings.

Installing a heated floor with connections is not forbidden, but it is not advised. However, you shouldn’t use a threaded method to connect the circuits. Connections work better with couplings. In order to accomplish this, a polyethylene film must be used to isolate the connecting element from the screed solution.

One common way to make connections is with soldering pipes. Taking a shaped part, coupling, or loop with a large diameter of roughly 60 mm is the coupling method used for this. By welding, the pipe’s edge is melted from the outside and the coupling is melted from the inside, securely joining the pieces together.

Details regarding the installation in the video:

Precautions

When using equipment, glue, or welding for plastic, standard safety precautions must be followed:

• protect your eyes with gloves and safety glasses;
• the room must be ventilated, where cleaning agents will be used;
• connections with glue are performed in an environment not exceeding a temperature of + 40 0 ​​C.

In the event that fittings are welded to a pipe:

• screw a nozzle with the required diameter onto the welding machine, you will need a hex key;
• turn on the device, set the temperature regulator to +260 0 C, in this mode, a reliable connection of fragments occurs;
• place the conductor and the nozzle with the fitting on different sides.

After the connection is made, check the structure to rule out any flaws using the connecting section. Safety measures to take when using a soldering iron:

• clean the pipe from dirt, seal the ends that will not be welded;
• place the soldering iron on a flat surface, connect, heat up;
• hold the coupling with the pipe in the heating bowl with the maximum immersion depth;
• after heating, connect the plastic parts, remove the excess behind the welding joint;
• check the connected place for tightness.

In order to complete the procedure correctly, you must:

• clean the areas to be connected;
• select suitable fittings;
• heat the pipe with the connecting element;
• connect the parts.

The connection will be strong if every step is carried out in order. It is advised to use water rather than lubricants when the pipe is tightly inserted into the fitting. The damaged portion of the underfloor heating system is removed when a breakdown happens. A film-wrapped coupling connects the entire circuit that is installed.

Pros and cons

Underfloor heating system connections must be made using fittings in the event that a pipe bursts from pressure or overheats beyond normal, or if mistakes are made when installing a single circuit. Fittings aid in error correction and proper laying.

Benefits of connecting elements use:

• carrying out partial repairs in the heating system without problems;
• strength of connections;
• getting rid of leaks;
• making branches if necessary;
• the ability to install valves and gate valves;
• joining communications of different diameters;
• making high-quality connections;
• increasing the service life;
• easy installation;
• wide selection of fittings by shapes, sizes, diameters, materials of execution.

Cons:

• difficulties with testing joints, shortcomings are revealed when starting the system;
• a strict selection of connecting elements for compliance with materials, sizes, diameters is required, any inaccuracy will lead to depressurization of the system.

Selecting the appropriate fittings for your underfloor heating pipes is essential to guarantee dependable and effective heating system operation. Manufacturers provide a range of fittings to suit diverse installation requirements and tastes. Depending on things like compatibility with your piping material, durability, and ease of installation, each type of fitting—compression, push-fit, or specialized—has advantages.

It’s crucial to take the manufacturers’ reputation and quality into account when choosing fittings. Reputable companies such as Wavin, Uponor, and REHAU are well-known for manufacturing long-lasting, high-quality fittings that meet industry standards. These manufacturers frequently offer thorough assistance and warranty choices, ensuring the peace of mind of installers and homeowners.

The process of installing underfloor heating pipe fittings usually consists of a few simple steps. Fittings are used to firmly join the heating pipes once they have been arranged in accordance with the design plan. This process may involve straightforward compression or push-fit techniques that only require basic plumbing equipment and specialized tools, depending on the type of fitting that is selected.

Overall, the efficiency and effectiveness of your underfloor heating system depend significantly on the fittings used during installation. By understanding the types of fittings available, choosing reputable manufacturers, and following proper installation procedures, you can ensure that your underfloor heating system operates smoothly, providing comfort and energy efficiency for years to come.

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