Pipe fittings: types, materials and maintenance

Any functional piping system relies on various pipe fittings to connect different parts of the system and ensure smooth flow. Fittings provide the necessary connections and play an important role in controlling, throttling, and directing fluids or gases.

Just like their various applications, there are many fittings to choose from to suit the specific functions you need them to perform in your piping network. So, in this article, we will discuss the most common types of fittings and their applications, what they are made of, how to maintain pipe fittings, how to choose the right pipe fittings for your system, and more.

Common Pipe Fitting Types and Their Applications

Pipe fittings and pipe couplings are widely used in any piping system to directly connect different parts or sections. They are available in a variety of sizes and shapes, so they are sometimes called adapters.

Fittings have a wide range of uses, such as branching, redirecting, regulating, controlling, throttling, etc. Therefore, there are a wide variety of fittings. Some of the most common fittings and their uses are discussed below.

Elbow Fittings

To change the direction of flow, a curved pipe fitting called an elbow should be used. This curve is mostly 90 degrees or 45 degrees. However, there is a type of elbow fitting that is 180 degrees, also known as a straight elbow fitting.

Moreover, elbow fittings are available in a variety of materials and sizes.

Tee Fittings

Tees look like a T-shape, so there are three openings. They are used to create branches and split the flow into two different directions. In addition, they can also merge two different sources into a single flow.

Tees are also made of different materials and come in different sizes. Some examples of tee fittings include: reducing tees, Y-shaped tees, straight tees, female and male branch tees, etc.

Coupling Fittings

When two pipes of the same diameter cannot be easily connected together (cannot be welded or threaded) to form a straight line, fittings are used to solve the problem.

There are many types of couplings, such as flexible couplings, rigid couplings, universal couplings, split sleeve couplings, and many more. Therefore, you can easily find a coupling that meets the requirements of your system.

Reducer Fittings

When two pipes of different sizes need to be connected, we need a reducer to achieve the transition. Concentric reducers maintain the centerline, and eccentric reducers move the centerline.

Union Fittings

Sometimes the system needs regular maintenance. For this purpose, removable joints allow for easy disassembly and reassembly of different parts. Union fittings are the best choice for making removable joints.

Moreover, there are two main types of joints: slip joints that can be easily installed manually and threaded joints that need to be tightened with a wrench.

Flange fittings

Flanges are used to connect any parts of a system such as valves, pipes, etc. by bolts or screws. They look like flat discs and provide a strong, leak-proof joint.

Moreover, you can get various types of flanges. Weld neck flanges, socket weld flanges, blind flanges, and RTJ flanges (or lap joint flanges) are some examples of flange fittings.

Cross joints

Cross joints are shaped like a cross and have four openings. These cross joints are used to make branch connections so that the medium can flow in multiple directions.

When the pipe sizes are the same, equal diameter cross joints are used; when the branch pipe sizes are different, reducing cross joints are used.

Caps and plugs

When you need to temporarily close the pipe, pipe caps and pipe plugs can play a role in temporary closure. This way, they prevent any contamination. Moreover, they can also be used to close the unused parts of the system.

Valves

Valves can start or stop the flow of fluids or gases, or even partially block a passage, to regulate, control, and direct flow. Although they are a type of fitting, they are often considered a separate category of process equipment.

You can learn all about valves in the following articles: Industrial Valves and Their Applications and A Simple Guide to Process Valves.

What are pipe fittings made of?

To make fittings suitable for any condition, they are made of a variety of materials.

· Steel: Steel fittings are strong and durable, and can withstand high temperatures and pressures. Carbon steel, stainless steel, and alloy steel are common steels used to make fittings.

· Copper: Copper fittings are ductile, so they can be easily shaped. In addition, they are corrosion-resistant and have good thermal conductivity. These properties make them popular in plumbing projects.

· PVC: PVC fittings are cheaper and lighter. In addition, they have good chemical and corrosion resistance.

· CPVC: CPVC fittings have the advantages of PVC fittings, but are also suitable for higher temperatures.

· Brass: Brass fittings are not only beautiful in appearance, but also very corrosion-resistant. They are mostly suitable for low pressure.

· Ductile Iron: Ductile iron fittings are very strong and durable. That is why they are popular in industrial environments.

· ABS: ABS fittings are lightweight and durable. Moreover, they are resistant to chemicals and low temperatures.

· HDPE: The main feature of HDPE fittings is their excellent chemical resistance.

It is crucial to select the right fitting material according to the conditions and usage to ensure that it can perform properly. We will discuss how to select the right fitting in the next section.