In-depth analysis of the multi-field applicability and excellent performance of 100 Brass Inverted Flare Fitting Tube Nut

What is 100 Brass Inverted Flare Fitting Tube Nut and why is it so important?

In complex and demanding fluid systems, safe and reliable connectors play a vital role. 100 Brass Inverted Flare Fitting Tube Nut, as a high-performance brass inverted flare fitting nut, is the leader in this category of key components. It not only provides a strong, sealed and safe connection solution, but is also widely used in air conditioning, refrigeration systems, fuel lines, hydraulic lines and other working conditions.

This product adopts a full brass body and steel nut structure, which ensures sufficient mechanical strength while taking into account corrosion resistance and economy. Its manufacturing standards strictly implement SAE J512 specifications, and it has passed UL certification and is suitable for flammable liquid and gas systems. Whether in high temperature or high pressure environments, it can provide long-term and stable sealing performance and is an indispensable component in many key systems.

Technical advantages of Inverted Flare structure

The so-called "Inverted Flare", that is, the "inverted flare" structure, is a sealing method widely used in pipe fittings. It forms a sealing surface that matches the inner conical surface of the joint by expanding the end of the metal pipe. During the tightening process, the conical surface of the pipe end forms metal-to-metal contact with the inside of the nut, and a high-pressure sealing effect can be achieved without an additional sealing gasket.

This structure has the following technical advantages:

High sealing: The core of the Inverted flare structure, which is favored by the engineering community, lies in the tight fit of "cone to cone". During the installation process, the pipe end is precisely expanded to form an external conical surface. When the nut is tightened, the conical surface will be pressed into the inner conical surface of the joint body to achieve direct contact between metals. This fitting method can achieve excellent sealing effect without using any rubber sealing rings, and is especially suitable for systems with extremely low leakage tolerance such as gas, refrigerant, and high-pressure oil lines. Even under high temperature and frequent pressure fluctuations, the structure can maintain reliable sealing to avoid safety hazards caused by gas or liquid leakage.

Strong anti-seismic performance: In many industrial application scenarios, such as mobile equipment, engines, ships or refrigeration systems, vibration is inevitable. Traditional plug-in or welded joints are prone to loosening due to metal fatigue or thermal expansion and contraction during long-term use, which in turn creates the risk of leakage. The Inverted Flare structure has a more stable overall connection structure and stronger anti-seismic performance due to the dual fixing method of thread locking + conical surface compression. This structure that combines rigidity and flexibility can still keep the joint stable in an environment with high-frequency vibration and frequent temperature changes, greatly reducing the risk of leakage caused by looseness and improving the long-term stability of system operation.

Good reusability: Compared with disposable joints or welded fixed pipe fittings, 100 Brass Inverted Flare Fitting Tube Nut supports multiple assembly and disassembly, which is particularly important in the maintenance process of long-term equipment. Since the sealing of the joint depends on the conical surface fit and the thread design is highly accurate, after disassembly, the maintenance personnel only need to ensure that the pipe end is not seriously damaged before reassembling and continuing to use it, reducing the frequency of joint replacement and spare parts costs. This reusable feature not only provides great convenience for equipment maintenance, but also significantly reduces the overall operating cost and improves the maintainability and sustainable operation of the system.

Easy installation: Traditional welding joints usually require high-temperature welding equipment and professional operation during installation, and there are hidden dangers such as unstable process and material changes in the heat-affected area. The installation process of 100 Brass Inverted Flare Fitting Tube Nut does not require welding, but can be completed only by flaring and mechanical tightening. This structure greatly simplifies the on-site construction process and is particularly suitable for engineering scenarios with limited space, inconvenient construction conditions or rapid deployment. Installers only need conventional tools to complete high-quality connections, which not only saves construction time, but also reduces operational risks and improves the overall operation efficiency of the system.

Why choose all-copper material? What performance improvements can it bring?

In the selection of various pipe fittings, brass is widely used in fuel, refrigeration, hydraulic, air conditioning and other systems due to its excellent comprehensive performance. 100 Brass Inverted Flare Fitting Tube Nut adopts an all-copper body structure, which is based on in-depth considerations of engineering practice and material science. As a copper alloy, brass not only has excellent processing performance, but also has good mechanical strength, sealing adaptability and durability. It is an ideal material choice for achieving "high-performance and high-reliability connections".

1. Excellent corrosion resistance and extended service life

Brass exhibits strong resistance to oxidation and chemical corrosion in a variety of media environments. Especially when dealing with corrosive media such as fuel, refrigerants, salt spray air or weak acid and alkaline fluids, traditional steel or iron-based joints may rust or corrode perforation, while brass can maintain surface stability and structural integrity.

This is particularly important for systems that operate under harsh conditions for a long time, such as:

Ship/marine engineering equipment, which is in a humid and high-salt environment all year round;

Air conditioning/refrigeration pipelines, which are exposed to frequent heat exchange processes and condensate;

Mobile machinery and vehicle systems, which are exposed to dust, mud, water and oil mixed environments.

The all-copper structure not only extends the service life of the connector itself, but also significantly reduces the replacement frequency and maintenance costs, providing guarantees for the stability and economy of system operation.

2. Excellent thermal stability, suitable for high-temperature systems

Brass has good thermal conductivity and thermal stability, and can withstand temperature fluctuations for a long time without material fatigue, deformation or thread failure.

This makes the connector widely applicable to:

High-temperature refrigeration systems (such as R410A, R134a systems);

Fuel pipeline connections in high-temperature environments in engine compartments;

Heat conduction systems such as hot oil and steam.

Compared with plastics or ordinary carbon steel, brass has stronger advantages in heat resistance and thermal expansion resistance, which not only ensures the sealing effect of the connection, but also avoids loosening and leakage caused by thermal expansion and contraction.

3. Wide compatibility with a variety of metal pipes

100 Brass Inverted Flare Fitting Tube Nut is highly adaptable and can be widely used in:

Copper pipes (soft copper pipes, hard copper pipes);

Aluminum pipes (lightweight piping systems);

Welded steel hydraulic pipes (high strength, high pressure environment);

Brass pipe fittings themselves.

Brass itself has good electrochemical stability with copper and aluminum, and is not prone to galvanic corrosion. In addition, it also has reliable sealing performance when combined with steel pipes, making it suitable for use in multi-metal mixed systems. This high compatibility provides greater flexibility and material selection space for system design.

4. Wear-resistant and pressure-resistant, adaptable to high pressure and impact conditions

Due to the moderate strength of brass, it is easy to form during processing, but it is also sufficient to withstand medium and high pressure liquid impact loads. Especially after being matched with a conical sealing structure, its pipe joints can still maintain a stable sealing state under high pressure, without relying on sealants or gaskets, which greatly improves the reliability and safety of the system.

This structural advantage is particularly prominent in hydraulic systems, fuel injection systems or refrigerant pulsating flow environments. Compared with some metals that are prone to brittle cracking or oxidation, brass' fatigue resistance also makes it more suitable for equipment with high-frequency start-stop or frequent vibration.

5. Durable and reusable

Another significant advantage of brass fittings is their excellent reusability. Without damaging the fitting body and pipe ends, this type of nut fitting can be disassembled and assembled multiple times without affecting its sealing performance. This has extremely high practical value for industrial systems, test equipment or experimental devices with frequent maintenance.

Quick and convenient assembly;

No special tools are required for disassembly;

Does not affect the sealing performance for the next use;

Suitable for on-site replacement and maintenance operations.

This reusability not only improves the efficiency of construction and maintenance, but also reduces the overall maintenance cost.

How to balance the economy and safety of steel nuts?

In the design of 100 Brass Inverted Flare Fitting Tube Nut, the material combination of "copper body + steel nut" is a deep reflection of the balance between performance and cost. This composite structure not only enhances the strength of the mechanical connection, but also effectively controls the overall manufacturing cost, achieving excellent cost performance while pursuing high reliability.

Why choose steel nuts?

As the core component of the connection structure, the nut plays a role far more than just fixing. It is also an important component that undertakes "locking, shear resistance, and anti-loosening" in the entire sealing and force-bearing system. In high-intensity and high-frequency industrial scenarios such as fuel systems, refrigeration systems, and hydraulic circuits, nuts often need to withstand two main types of working pressures:

High torque locking loads at the beginning of installation: During the initial installation process, operators usually use wrenches or pneumatic tools to tighten the nuts, which will exert a large axial pressure and torsional torque on the threads. The nuts must have sufficient torsional strength and structural rigidity, otherwise it is easy to cause "slippage" due to the yielding of metal materials, that is, the threads are damaged and lose the locking function.

Cyclic mechanical stress during the operation stage: During the operation of the equipment, the connection parts will produce repeated slight displacements due to vibration, temperature changes, or pressure fluctuations in the system, which will cause frequent axial tension and compression alternation. Under long-term action, the nuts need to have good fatigue resistance to prevent failure modes such as thread bite loosening and metal fatigue cracking.

Under this double stress test, if brass is used to make nuts, although its natural corrosion resistance and good processability can be utilized, it has the following obvious shortcomings in material mechanical properties:

Low yield strength: brass is relatively "soft" and is prone to plastic deformation when subjected to large torque, resulting in shallow thread engagement or dislocation;

Insufficient hardness: frequent disassembly and assembly will cause increased thread wear, and it is easy to "slip" or "stuck";

Easy to deform and affect sealing: once the nut is deformed due to uneven force or thermal expansion, it will directly affect the sealing fit between the cone and the pipe mouth, resulting in leakage;

Limited fatigue life: under high-frequency vibration or cyclic load conditions, brass is prone to stress concentration and microcrack expansion, accelerating the failure process of the nut.

Steel nuts effectively make up for this shortcoming:

High yield strength and shear strength: can withstand strong locking during high torque tightening to prevent thread damage;

Excellent fatigue resistance: suitable for multiple assembly and disassembly conditions, especially for industrial systems that require regular maintenance;

Good dimensional retention: can still maintain good matching accuracy after long-term use, and is not easy to loosen.

The composite structure of copper body + steel nut is not only not a simple "cost reduction", but also a structural and performance optimization design. The brass body provides excellent sealing and corrosion resistance, especially suitable for corrosive environments such as moisture and salt spray; while the steel nut solves the strength and durability problems in high torque environments.

This combination also has the following advantages:

Avoid electrochemical corrosion: Through surface treatment (such as galvanizing, nickel plating, etc.), steel nuts can effectively avoid galvanic corrosion when combined with brass;

Reduce thread slippage and thread biting: Steel nuts have higher hardness and are not easily "bitten" by the copper body, which improves maintenance convenience;

Improve overall stability: With the precise thread structure design, it is not easy to loosen even in an environment with frequent vibration or pressure fluctuations.

From a manufacturing perspective, brass is a relatively expensive non-ferrous metal. If the entire joint (including the nut) is made of all copper, the cost will increase significantly. By introducing carbon steel nuts or alloy steel nuts with higher strength but lower cost, not only the material consumption cost is reduced, but also the waste caused by frequent replacement of the entire joint due to nut damage is avoided.

In mass production and use, this composite structure has obvious cost advantages:

Under the same strength, the manufacturing cost is lower;

The maintenance cycle is longer, reducing unplanned downtime;

It can reduce inventory pressure, and only the nut needs to be replaced instead of the entire component.

How does it perform in terms of energy saving and maintenance costs?

In modern industrial systems, energy saving and maintenance cost reduction have become important indicators for measuring the performance of pipe fittings. 100 Brass Inverted Flare Fitting Tube Nut shows excellent comprehensive performance in this regard. It not only reduces energy consumption during the use cycle, but also effectively controls maintenance frequency and downtime costs. It is particularly suitable for systems with extremely high requirements for operational reliability.

1. Reduce the frequency of maintenance due to loose joints and corrosion

This product adopts a full brass structure body + high-strength steel nut design, which solves the common problem of "loose joints and corrosion failure" from the source:

The cone sealing structure ensures that it remains tightly fitted under pressure, does not rely on additional sealing rubber rings, and reduces the hidden dangers caused by aging of sealing materials;

The high corrosion resistance can resist moisture, salt spray, and chemical gas erosion for a long time, especially suitable for marine, frozen, acidic or oily environments;

The mechanical structure is stable, and it is not easy to loosen even in systems with high-frequency start-stop or continuous vibration, effectively reducing the risk of leakage;

Reduce the frequency of repeated inspections of loose and dripping parts by maintenance personnel, and reduce labor input.

2. Extend the system operation cycle and reduce downtime losses

Once the equipment is shut down due to loose joints or leakage, it will not only directly affect the efficiency of the production line, but also may cause damage to key components or environmental pollution. The 100 Brass Inverted Flare Fitting Tube Nut effectively improves the system's trouble-free continuous operation time (MTBF) through its stable and reliable structural design:

The nut and the tube body are not easily damaged after repeated disassembly and assembly, which is suitable for systems that require regular maintenance or replacement of components;

The reliable sealing structure avoids leakage of energy media, preventing system pressure drop or energy efficiency loss from the source;

Extends the equipment replacement cycle and avoids unplanned downtime caused by frequent disassembly and reinstallation;

It has significant economic benefits in continuous operation industries such as cold chain logistics, power generation equipment, and marine power.

3. High stability design suitable for low temperature, high temperature or corrosive occasions

Fluid control systems often face various extreme environments: -30℃ low temperature of refrigerated trucks, 120℃ high temperature in high-pressure diesel systems, or long-term salt spray erosion in offshore operating environments. The material and structure of the 100 Brass Inverted Flare Fitting Tube Nut provide it with natural advantages under these working conditions:

The brass body has good thermal stability and will not crack or deform due to thermal expansion and contraction, ensuring stable sealing;

The steel nut has extremely high mechanical strength and can still apply stable locking force even at high or low temperatures;

It is suitable for a variety of metal pipes such as copper, aluminum, and welded steel, with high compatibility, reducing inventory and procurement pressure;

Even if it runs for a long time in a corrosive environment, it can maintain connection performance and extend the life of the entire pipeline system.

With diversified product models, can they meet the needs of different pipe diameters?

In actual engineering applications, the fluid system has extremely high requirements for the matching accuracy of pipe sizes. Whether it is a thin-diameter refrigeration copper tube in an air-conditioning system or a medium-sized fuel pipeline in a diesel engine system, if the connector cannot be accurately docked, it will not only affect the convenience of installation, but also may cause serious consequences such as leakage and loosening.

The 100 Brass Inverted Flare Fitting Tube Nut series perfectly solves this industry pain point through finely divided product models. Its models range from 100-3 to 100-8, covering commonly used small-diameter metal tubes, fully meeting the different requirements of various equipment systems for the outer diameter of the tube.

1. Rich models, suitable for a variety of common pipe diameters

The following is an overview of the support range of different models for the outer diameter of the tube (Tube O.D.):

PART#	TUBE O.D	C	D	L
100-3	3/16	3/8	.196	.56
100-4	1/4	7/16	.259	.56
100-5	5/16	1/2	.321	.62
100-6	3/8	5/8	.384	.66
100-8	1/2	3/4	.508	.74

This multi-specification and multi-size design enables users to more accurately match the pipe diameter and connection standards used in their own system when selecting, avoiding the engineering risks of "replacing small with large" or "barely fitting".

2. Accurate parameter design facilitates technology selection and system integration

Thread size C: corresponds to the compatibility with the system interface during pipeline installation, affecting the nut tightening torque and sealing efficiency;

Flange diameter D: ensures that the flare area and the cone seal fit tightly, which is the core parameter of sealing performance;

Nut length L: affects the locking depth and installation space requirements, especially suitable for occasions where the internal space of the equipment is limited.

The detailed disclosure of these parameters not only provides an intuitive basis for design engineers, but also helps procurement and on-site construction personnel to achieve rapid comparison and efficient assembly.

3. Flexible matching to support customized needs

For engineering needs outside the standard, many equipment manufacturers and system integrators will also encounter the following scenarios:

Inconsistent pipe diameter standards in different countries or regions (such as the difference between the imperial system and the metric system);

Special wall thickness or special-shaped pipes require customized nut aperture or thread specifications;

Material strength or surface treatment level needs to be improved under high pressure or high corrosion conditions.

The 100 Brass Inverted Flare Fitting Tube Nut series not only provides multi-model support, but also has good customization adaptability. Some manufacturers can adjust parameters such as nut length, taper, inner hole finish, and fit tolerance according to customer drawings or samples to meet the precise connection requirements of non-standard occasions.

What industries and scenarios is this pipe fitting suitable for?

100 Brass Inverted Flare Fitting Tube Nut is not only a pipe connector with exquisite structure and strong sealing, but also has been widely used in many industries due to its excellent versatility and environmental adaptability. It can provide stable, reliable and long-term maintenance-free connection in a variety of fluid delivery systems, especially in harsh working conditions such as high temperature, high pressure and easy leakage.

1. Air conditioning and refrigeration system: high sealing ensures zero leakage of refrigerant

In household, commercial or industrial air conditioning, refrigerators, cold storage and other systems, refrigerant pipelines are often subjected to continuous pressure fluctuations and temperature differences. The 100 series brass inverted flare fitting relies on the sealing structure of cone to cone to ensure that the refrigerant does not leak, frost or pressure loss in the high-pressure cycle, significantly extending the life of the compressor and reducing system energy consumption. Due to its advantages of easy installation and repeatable disassembly and assembly, it is also particularly suitable for use in modular or split refrigerant systems, which is convenient for later maintenance and replacement.

2. Shipbuilding and marine engineering: perfect combination of corrosion resistance and earthquake resistance

The offshore operating environment has extremely high requirements for the corrosion resistance and structural stability of pipe fittings. The all-brass structure of the 100 Brass Inverted Flare Fitting Tube Nut has natural resistance to salt spray, moisture and heat, and can effectively resist the erosion of seawater, moisture or corrosive gases, ensuring the long-term operation of key parts such as ship engines, refrigeration systems, and hydraulic lifting devices. Its thread locking method combined with the inverted flare structure can effectively prevent loosening or leakage under severe vibration of the hull or long-term high load, and plays an important role in the ship maintenance system.

3. Engine system: high-safety connectors for fuel pipes and lubricating oil pipes

In internal combustion engines or diesel engines, the fuel system must withstand complex working conditions such as high-frequency pulsation and high-pressure atomization. 100 series pipe fittings can be precisely matched with copper, aluminum or welded steel pipes, and achieve self-locking seals through conical contact. They can be widely used in the following key passages:

Fuel inlet and outlet pipes;

Lubricating oil cooling circuits;

Vacuum pipe connections in exhaust gas recirculation (EGR) systems;

The high-strength steel nut structure also ensures safe locking during high-torque installation, avoiding fuel system pressure relief or oil return failures.

4. Mobile machinery and heavy equipment: Adapt to complex vibration and temperature change environments

In construction machinery (such as excavators, rollers, agricultural machinery) and mining equipment, the hydraulic and fuel pipelines are arranged in a compact space and in harsh working conditions. The reliability of the joints directly affects the operating stability of the entire machine. With its high sealing and strong anti-seismic performance, 100 series pipe fittings are widely used in:

Hydraulic control oil circuits;

High-pressure fuel injection systems;

Coolant circulation lines;

Especially under conditions of severe vibration and drastic temperature fluctuations (such as outdoor operations or construction in cold areas), brass materials show good thermal stability and fatigue life, avoiding loosening or leakage caused by thermal expansion and contraction.

5. The optimal solution for high temperature/high pressure fluid delivery systems

In high temperature working conditions such as chemical industry, food processing, energy equipment, etc., metal piping systems widely use copper or welded steel materials to transport high temperature liquids or gases. 100 Brass Inverted Flare Fitting Tube Nut can directly connect such pipes, relying on its:

Thermal stability up to hundreds of degrees Celsius;

Strong resistance to internal pressure bursting (thanks to the cone seal + metal thread structure);

Easy to disassemble and maintain;

It is especially suitable for those key process flows that require "no leakage, zero penetration", such as refrigerant compression stations, high temperature oil circulation systems, etc.