7 Essential Types of Fire Sprinkler System Fittings Explained

Abstract

This article presents a comprehensive examination of the components integral to modern fire suppression technologies, specifically focusing on the seven essential types of fire sprinkler system fittings. The inquiry delves into the functional roles and design considerations of elbows, tees, crosses, reducers, unions, caps, and flanges. It establishes a critical distinction between these specialized fittings and their counterparts in general plumbing, highlighting the non-negotiable requirements for material strength, pressure tolerance, and third-party certification (UL/FM) in life-safety applications. A significant portion of the analysis is dedicated to the material science of malleable cast iron, exploring its manufacturing process and the comparative advantages of black versus galvanized finishes in mitigating corrosion and ensuring system longevity. The objective is to provide engineers, installers, and facility managers with a nuanced understanding of how the meticulous selection and proper installation of high-quality fire sprinkler system fittings form the bedrock of a reliable and effective fire protection system, thereby safeguarding both property and human life.

Key Takeaways

• Select fittings based on the system’s specific pressure ratings and hydraulic design.
• Proper installation of fire sprinkler system fittings is paramount for system reliability.
• Malleable iron offers superior strength and ductility for fire safety applications.
• Regular inspection of fittings prevents leaks and ensures long-term system integrity.
• Understanding each fitting’s function is vital for effective fire protection design.
• Choose galvanized pipe fittings for enhanced corrosion resistance in wet systems.
• Always use certified components to comply with fire codes and safety standards.

Table of Contents

• Understanding the Foundation: What Are Fire Sprinkler System Fittings?
• 1. The Elbow: Changing the Flow’s Direction
• 2. The Tee Fitting: Branching the Lifeline
• 3. The Cross Fitting: Creating Four-Way Intersections
• 4. The Reducer: Transitioning Pipe Sizes
• 5. The Union: Facilitating System Maintenance
• 6. The Cap and Plug: Terminating the Flow
• 7. The Flange: Forging Strong, Serviceable Connections
• Material Matters: Why Malleable Cast Iron Dominates
• Installation and Maintenance: Ensuring Long-Term Reliability

Understanding the Foundation: What Are Fire Sprinkler System Fittings?

To contemplate a fire sprinkler system is to envision a network of pipes, a silent guardian waiting within the walls and ceilings of a structure. Yet, this network is not a monolithic entity. It is an intricate assembly of individual pipes and components, brought together into a functional whole by a specific class of hardware: fire sprinkler system fittings. These are not mere connectors; they are the joints, the knuckles, and the intersections of the system’s vascular network. Their function is to direct, divert, connect, and terminate the flow of water, ensuring it can travel from its source to a fire with maximum efficiency and reliability. The integrity of the entire fire protection system hinges on the quality and correct application of each fitting.

Imagine trying to build a skeleton without ligaments or joints. The bones would be present, but they would be a useless pile. In the same way, pipes without fittings are just lengths of metal. The fittings give the system its shape, its ability to navigate the complex anatomy of a building, and its capacity to deliver water precisely where it is needed. These components must perform their duty under the most extreme conditions—the intense heat and immense pressure of a fire event.

Distinguishing Fire Fittings from Standard Plumbing Fittings

A common and perilous misconception is to view the fittings used in a fire sprinkler system as interchangeable with those used for domestic water or drainage. This is a fundamental error in judgment. The demands placed upon a fire protection system are of a different order of magnitude. While a leaking tap in a kitchen is an annoyance, a failed fitting in a fire emergency is a catastrophe. The distinction rests on three pillars: material strength, pressure rating, and certification.

Fittings intended for fire protection are forged from materials, like ductile and malleable iron, specifically chosen for their ability to withstand high pressure and thermal stress. Standard plumbing fittings, often made from less robust materials, can rupture or melt when exposed to the conditions of a fire. Furthermore, every component in a fire sprinkler system, including the fire sprinkler system fittings, must meet stringent pressure requirements far exceeding those of typical plumbing.

To illuminate this distinction, consider the following comparison:

This table underscores a central truth: fire sprinkler system fittings are not a commodity but a highly engineered safety device. Their design and manufacture are governed by organizations like Underwriters Laboratories (UL) and FM Global (FM), which provide the third-party testing and certification that guarantees a fitting can perform as expected when lives are on the line.

The Language of Fittings: Threads and Connections

Communication depends on a shared language, and in the world of piping, that language is often spoken in threads. The way fittings connect to pipes and to each other is a matter of precise engineering. Two dominant thread standards are found globally: NPT (National Pipe Thread) and BSPT (British Standard Pipe Taper). NPT is the standard in the United States and Canada, while BSPT is common in Europe and Asia.

The fundamental difference lies in the angle of the threads and their shape (rounded for BSPT, flattened for NPT). Attempting to join an NPT fitting to a BSPT pipe will result in a connection that is not only insecure but is guaranteed to leak, a fatal flaw in a pressurized fire protection system. A professional installer understands this and ensures that all components within a given system adhere to a single, consistent standard.

Beyond threading, another method of connection has gained prominence: the grooved system. Grooved pipe fittings use a coupling that houses a gasket and clamps into grooves rolled into the end of the pipes. This method offers faster installation and provides a degree of flexibility to accommodate pipe movement or vibration, which can be an advantage in certain installations like seismic zones. The choice between threaded and grooved fire sprinkler system fittings depends on the specific project requirements, budget, and local labor practices.

1. The Elbow: Changing the Flow’s Direction

In the rigid, linear world of pipes, the elbow fitting introduces the concept of turning. A building is a three-dimensional space filled with beams, columns, ductwork, and other obstacles. A fire sprinkler system must artfully navigate this complex environment. The elbow is the primary tool for achieving this, allowing the piping network to bend and change direction without compromising the flow of water. It is perhaps the most common type of fitting one will encounter in any system.

The 90-Degree Turn

The 90-degree elbow is the workhorse of directional changes. It facilitates sharp, perpendicular turns, enabling pipes to run horizontally along a ceiling and then turn to run vertically down a wall, or to navigate around a square structural column. These fittings are ubiquitous, forming the corners that give the pipe network its shape. However, every sharp turn introduces friction, which slightly reduces water pressure. The system’s hydraulic design, a complex calculation performed by a fire protection engineer, must account for the cumulative pressure loss from every single elbow in the network to ensure adequate pressure remains at the furthest sprinkler head.

The 45-Degree Bend

When a less abrupt change of direction is needed, the 45-degree elbow is employed. Using two 45-degree elbows to create a 90-degree turn results in a more gradual, sweeping bend compared to a single 90-degree fitting. This gentler path reduces the turbulence of the water flow, which in turn minimizes the friction loss and the resulting pressure drop. In long pipe runs or in systems where pressure is marginal, using 45-degree bends can be a crucial design choice to maintain the hydraulic performance of the overall fire protection system.

Material Considerations for Elbows

During a fire, the water inside the pipes turns into a powerful, high-pressure torrent. As this torrent hits an elbow, it exerts immense force on the inner curve of the fitting. This is where material choice becomes paramount. A fitting made of inferior material could crack or burst under this stress, especially when weakened by the ambient heat of the fire. This is why high-grade, malleable iron fittings are the standard. Their inherent ductility, a result of a specialized heat treatment process, allows them to absorb these forces without fracturing, ensuring the corner holds and the water continues on its path.

2. The Tee Fitting: Branching the Lifeline

If elbows allow the pipe network to turn, tee fittings allow it to branch. A fire sprinkler system is like a tree, with a large trunk (the main riser pipe) that branches out into smaller limbs (cross-mains) and finally into small branches (branch lines) that feed the individual sprinkler heads. The pipe tee is the component that makes this branching structure possible. It is a T-shaped fitting with three outlets, allowing a single line of pipe to be split into two separate lines.

The Anatomy of a Pipe Tee

A tee fitting has two ports in a straight line, known as the “run,” and a third port at a 90-degree angle, known as the “branch” or “outlet.” Water flows through the run, and the branch allows a portion of that flow to be diverted into a new pipe line. This is the fundamental mechanism for distributing water throughout the entire building. For example, a large cross-main pipe will have multiple tee fittings along its length, with each tee’s branch feeding a smaller branch line that runs between ceiling joists to supply a row of sprinkler heads.

Straight Tees vs. Reducing Tees

Tee fittings come in two primary configurations. A “straight tee” has all three ports of the same diameter, meaning the branch pipe will be the same size as the main pipe. More common in fire sprinkler design, however, is the “reducing tee.” In a reducing tee, the branch port is smaller than the run ports. This is highly efficient, as branch lines are almost always smaller in diameter than the main or cross-main pipes they are fed from. Using a reducing pipe tee accomplishes two tasks at once: it branches the flow and reduces the pipe size in a single fitting, saving space, reducing costs, and simplifying the installation of the fire sprinkler system fittings.

Strategic Placement in System Design

The placement of every pipe tee is a deliberate decision driven by hydraulic calculations. The goal is to deliver a balanced flow of water to all sprinkler heads that might activate in a fire. Placing tees too close together or using incorrectly sized fittings can lead to pressure imbalances, where some sprinklers receive too much water while others are starved. Fire protection engineers use specialized software to model the flow through every pipe and fitting, ensuring that the tee configuration will perform as intended during an emergency. This meticulous planning highlights that a fire protection system is far more than just “plumbing for fires”; it is a finely tuned life-safety machine.

3. The Cross Fitting: Creating Four-Way Intersections

While the tee fitting creates a three-way junction, the cross fitting, as its name suggests, creates a four-way intersection. It has one inlet and three outlets, or four interconnected ports arranged in the shape of a cross. This allows a single inbound line to be split into three outbound lines, or for two intersecting lines to be joined.

When a Tee Isn’t Enough

Cross fittings are used much more sparingly than elbows and tees in fire sprinkler system design. Their primary application is in situations where branch lines need to be distributed in multiple directions from a single point, often in congested ceiling spaces. For example, a cross might be used at the center of a room to send four branch lines out towards the four walls. They can also be used to connect multiple sprinkler heads in a tight cluster, sometimes referred to as a “sprig” arrangement, directly off a main line.

Structural Integrity and Flow Dynamics

The geometry of a cross fitting introduces significant stress at the center point where the four lines meet. This makes the material strength and manufacturing quality of the fitting even more critical than for a simpler component like an elbow. High-quality malleable iron is essential to ensure the fitting can withstand the system’s operating and surge pressures without failure.

From a hydraulic perspective, cross fittings create more turbulence than tees. The colliding and splitting flows inside the fitting can cause a greater pressure drop. For this reason, engineers often prefer to use two separate tee fittings back-to-back instead of a single cross to achieve a smoother flow pattern, unless space constraints make a cross fitting the only viable option. The choice to use a cross is a calculated one, balancing the need for compact design against the potential hydraulic impact on the fire protection system.

4. The Reducer: Transitioning Pipe Sizes

The piping in a fire sprinkler system is not of a uniform size. It starts large at the water source and progressively steps down in diameter as it extends throughout the building. This is a fundamental principle of hydraulic design, ensuring that pressure and flow are managed effectively across the entire network. The fitting that makes these size transitions possible is the reducer. A reducer is a simple component that connects a larger pipe to a smaller pipe.

Concentric vs. Eccentric Reducers

Reducers come in two distinct shapes, each with a specific purpose.

• Concentric Reducer: This type is cone-shaped, with the center line of the large end and the small end aligned. It provides a symmetrical transition and is typically used in vertical pipe runs, where the change in diameter is centered on the pipe’s axis.
• Eccentric Reducer: This type has an offset design, where the bottom or top edge of the pipe remains level. The most common application is in horizontal pipe runs. By installing the eccentric reducer with its flat side on top (“FOT”), it prevents the formation of air pockets at the transition point. Air trapped in a wet pipe sprinkler system can accelerate corrosion and disrupt water flow during activation, so using eccentric reducers is a key detail in proper installation.

Managing Pressure and Velocity

The laws of fluid dynamics dictate that as the diameter of a pipe decreases, the velocity of the water flowing through it increases, and the pressure changes. Fire protection engineers use reducers strategically to control these variables. By stepping down the pipe size along a branch line, they can maintain adequate water velocity to ensure a rapid response time while managing pressure loss over the length of the pipe. The correct sizing and placement of every reducer are determined by the system’s hydraulic calculations, ensuring that the last sprinkler head on the longest run of pipe still receives the required pressure and flow to extinguish a fire. The selection of these fire sprinkler system fittings is a testament to the scientific precision underlying fire safety engineering.

5. The Union: Facilitating System Maintenance

A fire sprinkler system, once installed, is expected to last for decades. Over its lifespan, however, components like valves or pressure gauges may need to be replaced, or sections of the system may need to be modified. A pipe union is a special three-part fitting designed to make this maintenance possible without having to cut the pipes.

Designing for Disassembly

Unlike a standard coupling that permanently joins two pipes, a union is designed to be taken apart. It consists of three pieces: a male end, a female end, and a large nut that draws the two ends together. The male and female ends are threaded onto the pipes that need to be joined. To connect them, the nut is tightened, pulling the two halves together and creating a secure, leak-proof seal. To disconnect them, one simply has to loosen the nut. This simple but ingenious design allows a specific component or section of pipe to be easily removed and replaced, dramatically reducing the time and labor involved in system maintenance or repair.

The Importance of a Reliable Seal

The effectiveness of a union depends entirely on the quality of the seal it creates between the male and female ends. This is typically achieved through a precision-machined, ground joint metal-to-metal seal, or sometimes with the aid of a resilient gasket. In a high-pressure application like a fire protection system, a low-quality union with a poor seal is a significant liability. It can create a slow, persistent leak that can cause water damage over time or, worse, fail catastrophically under pressure. This is why sourcing unions from a reputable manufacturer of malleable cast iron fittings is so important. The precision engineering and robust materials ensure the union can be trusted to hold pressure for the life of the system.

6. The Cap and Plug: Terminating the Flow

Not every pipe in a sprinkler system is meant to be connected to another pipe. Sometimes, a line needs to be terminated. This is the job of the cap and the plug. These simple fire sprinkler system fittings serve the vital function of sealing the end of a pipe run, ensuring the pressurized water stays within the system.

Caps vs. Plugs: A Simple Distinction

The difference between a cap and a plug lies in the type of thread they have.

• A Cap: A cap has female (internal) threads and is designed to fit over the male (external) threads on the end of a pipe. Think of it as putting a cap on a bottle.
• A Plug: A plug has male (external) threads and is designed to screw into a fitting that has female (internal) threads, such as a tee or an elbow.

Both accomplish the same goal—sealing an opening—but are used in different contexts depending on the nature of the connection point that needs to be closed.

Future-Proofing the System

Caps and plugs are not only used for permanent terminations. They are also essential for future-proofing a building’s fire protection system. During construction, an engineer might design “stub-outs”—short lengths of capped pipe—at various points in the system. These provide easy connection points for future expansion. If a tenant later needs to reconfigure a space and add more sprinkler heads, an installer can simply remove the cap from a nearby stub-out and extend the piping, without having to shut down and drain the entire system. This foresight saves considerable time and expense during future renovations. Plugs serve a similar role, closing off unused ports on fittings like tees, which can be removed later if that port is needed.

7. The Flange: Forging Strong, Serviceable Connections

While most of the pipe network is joined by threaded or grooved fittings, there are situations where a different type of connection is required, particularly when joining pipes to large equipment or when a robust, easily serviceable junction is needed. This is the role of the flange. A flange is a flat rim or collar that is welded or threaded onto the end of a pipe. Two flanges are then bolted together with a gasket in between to create a strong, sealed connection.

The Role of Floor Flanges

A specific type of flange, the floor flange, serves a structural as well as a sealing purpose. A floor flange has a flat base with holes for bolts or screws. It is threaded onto a pipe and then secured to a floor, wall, or ceiling. This provides a rigid anchor point for the pipe, preventing it from moving or vibrating. While more common in plumbing for securing fixtures, they are used in fire protection systems to provide support for risers and other key piping elements, ensuring the system’s structural stability.

Connecting to Larger Equipment

The primary use for flanges in a fire protection system is to connect the pipe network to major components like the main system control valve, backflow preventers, and fire pumps. These large, heavy pieces of equipment cannot be easily connected with a simple threaded fitting. Instead, they are manufactured with flanged outlets. The system piping is then fitted with a corresponding flange, and the two are bolted together. This method creates an incredibly strong connection capable of withstanding the immense pressures generated by a fire pump. It also allows for the equipment to be easily isolated and removed for service or replacement simply by unbolting the flanges, a task that would be impossible with a permanent, threaded connection.

Material Matters: Why Malleable Cast Iron Dominates

The performance of every elbow, tee, and union in a fire sprinkler system is fundamentally determined by the material from which it is made. While various materials are used in piping, the domain of threaded fire sprinkler system fittings is dominated by one in particular: malleable cast iron. Its prevalence is not accidental; it is the result of a unique combination of strength, durability, and workability that makes it ideally suited for the demands of life safety.

The Alchemy of Malleable Iron

Standard cast iron is strong but brittle; under sharp impact or stress, it can fracture. Malleable iron begins its life as a standard white iron casting, but then undergoes a prolonged heating process called annealing. This carefully controlled heat treatment, lasting for several days, changes the microstructure of the iron. The brittle carbon structures within the metal transform into more rounded graphite nodules. This metallurgical alchemy imparts a degree of ductility to the iron, allowing it to deform slightly under stress rather than shattering. This toughness is precisely what is needed in a fire sprinkler fitting, which must endure the rigors of installation (tightening with wrenches) and the dynamic forces of water hammer and high-pressure flow during activation.

Black Pipe Fittings vs. Galvanized Pipe Fittings

Malleable iron fittings for fire protection are typically available in two finishes: black and galvanized. The choice between them is primarily a matter of corrosion resistance.

In a “wet pipe” system, the most common type of sprinkler system, the pipes are always filled with water. Here, using galvanized pipe fittings is the superior choice. The zinc coating provides a robust barrier against rust, preventing internal corrosion that could otherwise weaken the fitting or clog the sprinkler head with debris. For “dry pipe” systems, used in unheated areas like parking garages where water would freeze, black pipe fittings are often sufficient, as the pipes are filled with pressurized air until the system activates.

The Assurance of Quality and Certification

In the context of a life-safety system, the provenance of a fitting is not a trivial detail. A fitting is not just a piece of metal; it is a promise of performance. This promise is validated through third-party certification from organizations like UL and FM Global. These agencies subject fire sprinkler system fittings to a battery of rigorous tests, evaluating their pressure-retaining capability, resistance to thermal shock, thread integrity, and material composition. Only fittings that pass these tests earn the right to bear the UL or FM mark. This mark is the installer’s and the building owner’s assurance that the component meets the highest standards for fire safety and will not be the weak link in the chain of protection.

Installation and Maintenance: Ensuring Long-Term Reliability

The finest, most precisely engineered fire sprinkler system fittings can be rendered ineffective by poor installation. Conversely, a correctly installed system requires diligent maintenance to ensure it remains ready to perform over its multi-decade service life. The reliability of a fire protection system is a shared responsibility between the quality of its components and the craftsmanship of its installation and care.

The Craft of Proper Installation

Installing threaded pipe fittings is a craft that requires more than just brute force. Each threaded joint must be sealed to be both water-tight and air-tight. This is achieved using either a specialized pipe sealant compound (pipe dope) or PTFE tape. The sealant not only fills the microscopic gaps between the threads to prevent leaks but also lubricates the threads, allowing for a smooth and tight connection.

A critical aspect of the craft is applying the correct amount of torque. Under-tightening a fitting will result in a leak. However, over-tightening is equally dangerous. Excessive torque can stretch the threads or even crack the fitting, creating a stress point that could fail under pressure. Experienced installers develop a feel for the proper torque and use appropriately sized wrenches to avoid exerting too much force on the fitting. It is a balance of strength and finesse.

The Vigilance of Inspection

A fire sprinkler system is not a “set it and forget it” installation. It is a dynamic system that must be regularly inspected, tested, and maintained (ITM) in accordance with standards like the National Fire Protection Association’s NFPA 25. During these inspections, qualified technicians visually examine accessible components, including the fire sprinkler system fittings. They look for signs of trouble: corrosion, physical damage from impact, and evidence of leaks. A small rust spot or a slight drip from a fitting might seem minor, but it can be an early warning sign of a more significant problem that needs to be addressed before it can compromise the system’s readiness.

The Silent Threat of Corrosion

Perhaps the most persistent threat to the long-term health of a fire sprinkler system is internal corrosion. Over years, the interaction between water, trapped air, and the metal of the pipes and fittings can lead to the formation of rust and sludge. In severe cases, a phenomenon known as Microbiologically Influenced Corrosion (MIC) can occur, where bacteria accelerate the corrosion process, eating away at the pipe walls from the inside.

This corrosion can cause two major problems. First, it can create pinhole leaks in the fittings and pipes. Second, the rust and debris can become dislodged during system activation and clog the small orifice of a sprinkler head, preventing it from discharging water. The choice of materials, such as using galvanized fittings in wet systems, and proper system maintenance, like periodically draining and flushing the lines, are key strategies in the ongoing battle against this silent threat.

Frequently Asked Questions (FAQ)

Q1: Can I use standard plumbing fittings from a hardware store for a fire sprinkler system? No, you absolutely cannot. Standard plumbing fittings are not designed or tested to withstand the high pressures and extreme heat of a fire event. They lack the required UL/FM certifications for life-safety applications. Using them would create a dangerous point of failure and violate all fire codes.

Q2: What is the main difference between black iron and galvanized pipe fittings? The primary difference is corrosion resistance. Galvanized pipe fittings are coated in a layer of zinc, which protects them from rust, making them ideal for wet pipe sprinkler systems that are constantly filled with water. Black pipe fittings have a minimal protective coating and are better suited for dry pipe systems where water is not present until activation.

Q3: How do I know which size of fire sprinkler system fittings to use? The size of all pipes and fittings in a fire sprinkler system is determined by a fire protection engineer during the system design phase. This involves complex hydraulic calculations to ensure that every sprinkler head will receive the necessary water pressure and flow rate to control a fire. It is not something that can be chosen arbitrarily.

Q4: What are NPT and BSPT threads, and can they be mixed? NPT (National Pipe Thread) is the standard used primarily in North America, while BSPT (British Standard Pipe Taper) is common in Europe and other parts of the world. They have different thread angles and profiles. They are not compatible and must never be mixed, as doing so will create a leaking and unreliable connection.

Q5: Why are grooved fittings sometimes used instead of threaded fittings? Grooved fittings can be installed much faster than threaded fittings, which can reduce labor costs, especially on large projects. They also provide some flexibility in the pipeline to accommodate thermal expansion, contraction, or seismic movement. The choice between grooved and threaded systems often depends on project specifications, budget, and the preference of the installing contractor.

Q6: How often should fire sprinkler system fittings be inspected? According to NFPA 25, the standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, visual inspections of sprinkler system components, including accessible fittings, should typically be conducted annually. However, the frequency can vary based on the type of system and the specific environment.

Conclusion

The examination of fire sprinkler system fittings reveals a world of precision engineering and material science operating silently behind our walls and above our ceilings. These components—the elbows, tees, reducers, and unions—are far more than simple hardware. They are the anatomical structures that give a fire protection system its form and function. Their capacity to reliably direct high-pressure water flow in the extreme environment of a fire is a direct result of the materials from which they are made, the standards to which they are certified, and the care with which they are installed.

Understanding the distinction between a common plumbing part and a certified, malleable iron fire fitting is to understand the difference between a convenience and a commitment to life safety. The integrity of these small but mighty components underpins the effectiveness of the entire system. A well-designed, properly installed, and diligently maintained fire sprinkler system, built with high-quality fittings, represents one of the most profound investments a society can make in the preservation of property and, more importantly, in the protection of human life. It is a silent promise of security, held together by threads of iron.

References

Jianzhi pipe fittings. (2024, December 17). Why are fire pipe fittings important in fire safety systems? Jianzhi Group. https://www.jianzhipipefitting.com/2024/12/17/why-are-fire-pipe-fittings-important-in-fire-safety-systems/

Jianzhi pipe fittings. (n.d.). Malleable iron pipe fittings & grooved pipe fittings. Jianzhi Group. https://www.jianzhipipefitting.com/

Malleableiron-pipefitting.com. (n.d.). Malleable iron pipe fittings, cast iron grooved pipe fittings manufacturer. Jianzhi Group. https://www.malleableiron-pipefitting.com/

National Fire Protection Association. (n.d.). NFPA 13: Standard for the installation of sprinkler systems. https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=13

National Fire Protection Association. (n.d.). NFPA 25: Standard for the inspection, testing, and maintenance of water-based fire protection systems. https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=25

Simplex Steel Industries. (2024, November 25). Types of pipe fittings and their uses. Simplex Fittings Blog. https://www.simplexfittings.com/blog/types-of-pipe-fittings-and-their-uses/