15 Types of Pipe Fittings

Pipe fittings join different pipes. They change a pipe’s direction. They also change a pipe’s size. They are crucial for plumbing. They are also essential for HVAC systems. Furthermore, they are vital in industrial piping. Different types of pipe fittings exist for various purposes. This guide details common pipe fitting types. This information helps you choose the correct fitting for your project.

This section explores different pipe fitting categories. Each category serves a unique purpose in piping systems, and understanding these categories is crucial for selecting appropriate fittings.

Connecting fittings join two pipes, creating a continuous flow path. They are essential for extending pipe runs or joining different segments.

• Coupler: A coupler joins two pipes of the same diameter. It creates a straight connection. Common materials include PVC, copper, and steel. Couplers find applications in plumbing, irrigation, and HVAC systems. They provide a simple and effective way to extend pipe lengths. Coupling is an important skill to learn when working with pipe fittings.
• Union: A union also connects two pipes of the same diameter. However, it allows for easy disconnection. This feature is essential for maintenance and repairs. A union comprises three parts: a nut, a female end, and a male end. The nut tightens onto the female and male ends, creating a secure seal.
• Adapter/Reducer: Adapters and reducers connect pipes of different diameters. An adapter joins dissimilar pipe types or sizes, while a reducer specifically decreases pipe size within a system. They facilitate transitions between different pipe sections and are essential for maintaining flow and pressure.

Branching fittings create multiple flow paths, diverting fluids in different directions. These fittings are crucial for complex piping networks.

• Tee: A tee creates a 90-degree branch from the main pipe run. Its shape resembles the letter “T.” Tees distribute flow in two directions. They are commonly used in water supply lines and drainage systems.
• Cross: A cross creates four flow paths, resembling a plus sign. This fitting allows fluid to flow in four directions. Crosses are essential for complex piping layouts, distributing fluids to multiple locations.
• Y-Fitting: Also known as a wye, a Y-fitting creates a branched connection that splits the flow at an angle. This angle reduces friction and turbulence compared to a sharp T-intersection. Y-fittings are often used in drainage systems.

These fittings change the direction of the pipe run, allowing for flexibility in piping design.

• Elbow (90°, 45°): Elbows change the pipe’s direction at specific angles. Common angles are 90 and 45 degrees. 90-degree elbows create sharp turns, while 45-degree elbows offer gentler turns. They are fundamental for navigating corners and obstacles.
• Bend: Bends create gradual curves in the pipe run. They offer a smoother transition than elbows. Bends minimise pressure drop and turbulence. They are used when a less abrupt change in direction is required.

Other fittings serve specialised purposes, such as completing the piping system.

• Caps: Caps close the end of a pipe, preventing leaks and debris from entering. They provide a secure seal at the termination point of a pipe run.
• Plugs: Plugs seal an opening in a fitting, closing off unused connections or ports. They ensure a closed system and prevent leaks.
• Valves: Valves control fluid flow within a piping system. Different valve types exist, including ball, gate, and check valves. Each type offers specific control mechanisms.

Certain applications require specialised fittings. These fittings address specific needs within a piping system.

• Reducers: Reducers connect pipes of different diameters. They facilitate a smooth transition between different pipe sizes, maintaining flow and pressure. Reducers are essential for incorporating various pipe sizes within a single system. They come in concentric and eccentric types. Concentric reducers maintain a centered alignment, while eccentric reducers offset the alignment.
• Nipples: Nipples are short pipe sections with male threads on both ends. They extend connections between other fittings or valves. Nipples provide a short, rigid connection, often used in tight spaces. They come in various lengths and diameters.
• Bushings: Bushings join pipes of different diameters by fitting inside a larger fitting. A bushing reduces the port size of a fitting to accommodate a smaller pipe. They provide a secure and leak-free connection.
• Flanges: Flanges provide strong, stable connections for larger pipes or heavy-duty applications. They consist of two mating plates bolted together with a gasket between them to create a seal. Flanges are commonly used in industrial settings and high-pressure systems. They allow for easy disassembly and maintenance.

Pipe fittings come in various materials. Each material possesses different properties. These properties determine suitability for specific applications. Choosing the correct material ensures system longevity and performance. Material choice impacts compatibility, pressure rating, and temperature resistance.

• PVC (Polyvinyl Chloride): PVC is a common, cost-effective plastic that is lightweight and easy to install. It offers excellent corrosion resistance, making it suitable for cold water plumbing and irrigation. However, PVC is not suitable for high temperatures or high-pressure applications.
• Copper: Copper is a durable metal, highly resistant to corrosion. It’s suitable for both hot and cold water applications and is commonly used in plumbing, HVAC, and gas lines. While more expensive than PVC, copper offers a long lifespan and inherent antimicrobial properties. It can be susceptible to pitting corrosion in acidic water.
• Steel: Steel offers exceptional strength and robustness, making it suitable for demanding applications requiring high pressure and temperature tolerance, often in industrial piping and high-pressure water systems. However, steel is susceptible to rust and corrosion, necessitating proper coating or galvanisation. Stainless steel provides superior corrosion resistance but comes at a higher cost.
• Brass: Brass, an alloy of copper and zinc, combines corrosion resistance with an aesthetically pleasing appearance. Durable and suitable for potable water, it’s frequently used for plumbing fixtures and decorative applications. However, brass is more expensive than other options and can be susceptible to dezincification in some water conditions.
• CPVC (Chlorinated Polyvinyl Chloride): CPVC is a higher-grade plastic than standard PVC, offering better temperature and pressure resistance as well as good chemical resistance, making it suitable for hot water supply lines and industrial applications. While more expensive than PVC, CPVC can become brittle with prolonged UV exposure.

Choosing compatible materials is essential. For instance, using dissimilar metals can lead to galvanic corrosion, particularly in the presence of water, weakening the system over time. When selecting fittings for a water pump, consider the pump’s operating pressure and the fluid’s temperature. High-pressure pumps necessitate fittings with corresponding pressure ratings. Corrosive water may require stainless steel or CPVC fittings for long-term reliability.

Proper installation is crucial for a reliable and leak-free piping system. While specific installation techniques vary depending on the pipe and fitting materials, some general considerations apply.

• Cleanliness: Ensure all pipe and fitting surfaces are clean and debris-free before joining. Dirt or debris can compromise the seal, leading to leaks.
• Proper Tools: Use appropriate tools for cutting and joining pipes. Incorrect tools can damage the fittings or pipes, creating weak points in the system.
• Pipe Sealant/Thread Tape: For threaded fittings, apply thread sealant or PTFE tape to the male threads. This creates a watertight seal. Ensure not to over-tighten threaded fittings, which can damage the threads or crack the fitting.
• Support and Alignment: Properly support pipes and fittings to prevent sagging or stress on the joints. Misalignment can lead to leaks or premature failure.
• Testing: After installation, test the system thoroughly for leaks. Address any leaks promptly to prevent damage or water waste.

This section provides general guidance. Consult specific manufacturer instructions for detailed installation procedures for your chosen materials. Incorrect installation can void warranties. For complex installations or if you need clarification, consult a qualified plumber.

In new homes in Australia, the most commonly used plumbing pipes are:

1. PVC (Polyvinyl Chloride): Widely used for wastewater and stormwater drainage due to its affordability and versatility.
2. PEX (Cross-linked Polyethylene): Frequently used for hot and cold water supply in residential applications.
3. Copper: Still popular for its durability, corrosion resistance, and excellent heat conductivity, making it ideal for hot water lines.
4. Polypropylene (PP): Used for specific applications, offering durability and chemical resistance.
5. CPVC (Chlorinated Polyvinyl Chloride): Utilised for hot and cold water distribution and domestic sprinkler systems.

These materials are chosen based on cost-effectiveness, durability, ease of installation, and specific plumbing requirements. PVC and PEX are increasingly popular in new construction due to their lower cost and ease of installation compared to traditional copper pipes.

Polybutylene (PB) plumbing was not banned outright in Australia as it was in some other countries. However, the use of certain PB pipes has been phased out due to widespread issues:

1. In 2005, a specific type of PB piping was banned in Australia due to its reputation for being prone to leaks and ruptures.
2. Recently, issues have arisen with Pro-fit (Typlex 1050) polybutylene pipes manufactured by Iplex Australia. While not officially banned, these pipes have been the subject of significant concern and remediation efforts.
3. As of 2024, the Western Australian government has addressed problems with Typlex pipes, including introducing legislation to extend the period for making complaints about leaky Typlex 1050 pipes to 15 years.

It’s important to note that while PB piping is no longer commonly used in new construction in Australia, many homes built before these issues were recognised may still have PB plumbing installed.