90 Degree Pipe Elbow Fittings

A 90-degree pipe elbow fitting is a type of pipe fitting that changes the direction of a piping system by 90 degrees. These fittings are commonly used in plumbing and industrial piping to redirect the flow of fluids or gases in a system. They are available in various materials, including carbon steel, stainless steel, aluminum, and plastics, and can be either threaded or socket weld (SW), soldered, or brazed, depending on the application and the type of pipe used.

### Types of 90-Degree Elbows

1. **Long Radius (LR) Elbows**: These elbows have a center-to-end distance that is 1.5 times the pipe's nominal size (NPS). They are used when less turbulence and stress on the管道 system are desired.

2. **Short Radius (SR) Elbows**: These elbows have a center-to-end distance equal to the pipe's nominal size. They are more compact than long-radius elbows but can cause more turbulence in the flow.

3. **Forged Elbows**: These are typically stronger than cast elbows due to the forging process, which aligns the grain structure of the material, resulting in better mechanical properties.

4. **Cast Elbows**: These are made by casting molten metal into a mold and are suitable for less demanding applications.

### Specifications

- **Size**: 90-degree elbows are available in a range of sizes, from very small (such as 1/2 inch) to very large (such as 60 inches or more), to fit different pipe sizes.

- **Pressure Class**: The pressure class of the elbow should match the pressure rating of the system it is being installed in. This is often indicated by the Schedule (Sch) number for carbon steel and stainless steel elbows.

- **Material**: The material used will depend on the application and the type of fluid or gas being conveyed. Common materials include:

- Carbon Steel: For standard plumbing and industrial applications.

- Stainless Steel: For corrosion-resistant applications and where high temperatures are involved.

- Aluminum: For lightweight applications and where corrosion resistance is required.

- Plastic: For non-pressurized or low-pressure applications, such as irrigation systems.

### Installation

- **Threaded Elbows**: These are installed by threading them onto the male ends of the pipes.

- **Socket Weld Elbows**: These are used in high-pressure systems and require a socket weld to join the pipes.

- **Soldered/Brazed Elbows**: These are used for copper and other metal pipes that can be soldered or brazed together.

### Applications

- **Plumbing Systems**: For redirecting water or waste in residential, commercial, and industrial plumbing.

- **Industrial Piping**: For use in process piping, power generation, and oil and gas applications.

- **HVAC Systems**: For directing the flow of air in heating, ventilation, and air conditioning systems.

When installing 90-degree elbows, it is important to consider the flow characteristics of the fluid or gas in the system to ensure proper piping design and to avoid unnecessary pressure drops or turbulence. Always select elbows that are compatible with the pipe material, size, and pressure ratings of the system.