Features of flare nuts

In appearance, such an insignificant coupling element as a union nut is an indispensable part for connecting water supply and heating pipelines, for gas pipes, it participates in the air conditioning system, it is used in the automotive industry and other important industries. Let's see what a union nut is, what it is for, what types it is and how it is installed.

The nut is a threaded ring in the inner part, in this it differs from the union, which has an external thread. The outer surface may look different, but it is designed in such a way that it can be easily grasped by the working tool. The nut has a connecting purpose, with its help axial installation takes place.

The union nut becomes an integral part of such connecting elements as "American", coupling, many types of fittings. It is made from different materials with strict adherence to GOSTs. They control the ratio of sizes, shape, strength, and purpose of the nut. The shape of the product can be cylindrical or petal, the most common option is a hexagon.

The union nut is often called "American", in fact, this connecting object, in addition to the nut, contains several more elements. Having studied the history of this product, it is difficult to understand why the union nut is American, if its invention is attributed by some to the Germans, others to the Swiss. One thing is clear in this story, today pipelines of many countries of the world cannot do without the "American".

The "American" nut can be used several times, you just need to install a new gasket. The usual overhead nut differs from the "overseas" in size, it is used in cramped conditions, where it is difficult to get close with more voluminous fasteners.

Before talking about the purpose of the union nut, let's summarize the above. The collar nut can be used as a separate element or be an integral and very important part of any fitting, including couplings or "American". Being in these structures, it also performs its connecting function flawlessly. Therefore, talking about any of these technical devices, we mean the work of the nut itself.

Union nuts alone or in detachable joints can be used in the following cases:

• during the installation of a mixer in the bathroom, radiator, toilet cistern;
• they are used in the joints of annular fittings, on cutting rings, in high-pressure hoses;
• for connecting the reducer to the gas cylinder valve;
• quick installation and dismantling of the circulation pump;
• to install a household meter;
• during the connection of the heated towel rail with the water supply system;
• for mounting a quick-release connection on a damaged section of the line;
• for introducing tees, taps, adapters and other working devices into the system;
• for connections of technical pipelines designed for the transportation of non-aggressive liquids, union nuts with locking holes are used (GOST 16046 - 70).

Installation of pipelines of any systems involves a large number of adapters, branches and connections, in the docking of which devices with union nuts are involved. Nuts can be used in corner and straight joints, they are able to combine complex structures. Their main task is to ensure the strength, durability and tightness of the connection. Consider what types of connecting devices are, based on the work of union nuts.

Such devices are used when it is necessary to join pipes located at an angle. Instead of adapters, you can use reliable and aesthetically pleasing "American" with union nuts, produced in various diameters. They are capable of servicing pipelines at an angle of 45 to 135 degrees.

The connecting functions of corner fittings are smooth, the nut provides a virtually sealed tightness of the joints, rationally distributing the pressure on the rubber gasket. If necessary, the device can be removed without undue effort and repair or replacement of the pipeline section can be made.

This device is designed to connect straight trunk sections. Inch thread allows joining both metal pipes and PVC products. The device only seems simple in appearance, in fact, it can serve for many years without replacement for the entire operational life of the system. But if you need to make a replacement, the nut will allow you to simply unscrew the coupling. By the way, it can be used repeatedly, this does not impair the performance of the device.

Successfully replaced the squeegee used in the past. The body of the structure contains a quick-release union nut, several fittings, nipples and seals. The device is a strong, durable unit, which is located under the toilet bowls, sinks, water heating devices, at the entrance areas of the plumbing system to the apartment.

Threaded cone fittings can easily withstand high temperatures, so they are installed in heating or hot water supply systems. Such couplings are not endowed with gaskets, their contact reliability is ensured by the tightness of pressing of the connecting elements. The absence of gaskets helps to avoid their sagging at high temperatures. On a straight "American", on tubes with cold water, you can independently put a sealing tape to avoid even the smallest likelihood of leaks. Winding the FUM tape will ensure the tightness of the joint.

The device is a traditional type of "American" with a flat mount, which is easily mounted using a wrench. The union nut on the side provides a tie with the pipe, and the gasket material is responsible for the tightness. In flat washers installed on devices, the gaskets sooner or later sink and leak, so it is not recommended to mount them in the walls, the best option would be to leave them in plain sight.

Despite the simple appearance, thermal and mechanical processes are involved in the production of nuts. Manufacturing technology includes several stages. The union nut is made of various materials or alloys, but they must be reinforced with additional properties. They add softness, or vice versa, strength, anti-corrosion characteristics, resistance to aggressive liquids and gases, to temperature fluctuations. The acquired properties make it possible to use the products in pipelines with different purposes.

A variety of nuts is achieved by using different types of alloys, using dissimilar temperature conditions and processing methods. For their manufacture, alloyed, stainless, carbon steel is used.More expensive products include non-ferrous metal nuts.

Let us consider in more detail the materials used in the production of union nuts.

• Steel. Stainless steel union nuts have good strength and long service life. They do not deform from time to time, are not influenced by the external environment. In terms of cost, they can be attributed to the goods of the middle category.
• Galvanized. To reduce the cost of the product, no additives are introduced into the ferrous metal to acquire resistant properties to corrosion, but a protective layer is applied on top, the so-called galvanizing is performed. Products can contain up to 95% zinc on their surface. Depending on the purpose of the union nuts, galvanizing is carried out in different ways: cold, hot, thermal gas, galvanic, thermal diffusion. But the indicators of durability that stainless steel has, they cannot acquire.
• Brass. Today, polypropylene is often used as a material for pipes. It is easier to connect such products with "American" brass nuts, which are reliable and durable. The alloy is resistant to high temperatures, aggressive environment, has sufficient strength and relative elasticity. The disadvantages include the high cost and loss of fresh shade over time. To avoid discoloration, products are chrome-plated and powder coated.
• Copper. They are expensive and hardly in demand. They are produced in small batches and are used mainly for connections with products from the same metal. Copper plumbing is purchased for retro styles, in other cases it is difficult to justify the quickly appearing greenish patina and dark shade of the surface. Copper cap screws do not withstand aggressive environments and are easily subject to electrolytic corrosion.
• Plastic. Plastic in its pure form cannot withstand the load of highways, therefore, to create "American women", a combined product is used - metal threaded inserts are wrapped in a polymer form. These types of products are used in pipelines with high pressure and high temperature conditions.

The union nut is a connecting element, it must withstand strong stress in pipeline systems for various purposes. The product can be used independently or as part of a fitting, it is used for different purposes, therefore it has different dimensions.

To connect water and gas pipes along the outer cone, 3/4, 1/2 inch union nuts are used. After installation work, the connecting elements must withstand a hydrostatic pressure test exceeding the working pressure by 1.5 times.

A variety of sizes (inner diameter 30, 22, 20, 16, 12 mm) allows the use of union nuts not only for connection work in large-scale projects for the arrangement of highways, but also in domestic conditions. Thanks to "American women", we can easily install plumbing equipment in our apartments.

To connect two steel pipes on a line, you need to do the following:

• 7-9 threads are cut at the connecting ends;
• prepare fittings with internal and external threads;
• a sealant is wound on one of the pipes and a device with an external thread is wound;
• the second pipe is also sealed, but a fitting with a collar is screwed onto it, on which a union nut is installed;
• at the final stage, the union nut is screwed to the counterpipe.

Installation is effortless as only an appropriately sized spanner is used. The connection takes place in a small area and does not affect the integrity of the rest of the trunk.

The following video talks about flare nuts.