Selection and installation method of 45-degree elbow

When selecting a 45° elbow, consider the following aspects:

1. Material Selection: Choose materials based on the application scenario:

Carbon steel elbows: Suitable for general pressure pipelines such as steam, oil, and gas.

304/316 stainless steel elbows: Suitable for environments with high corrosion resistance requirements, such as food, pharmaceutical, chemical, and water treatment industries.

Alloy steel elbows: Used in high-temperature, high-pressure, and high-strength applications such as steam boilers and heating pipelines.

PVC, PPR, PE, and other plastic elbows: Used for water supply and drainage, home piping, and agricultural irrigation systems.

2. Wall Thickness Matching: The elbow wall thickness should match the main pipe wall thickness. Generally, it should be selected according to pipe standards, such as the commonly used SCH40 and SCH80. Elbows with a lower strength than the main pipe should not be used to avoid weak points.

3. Connection Method Selection: The principle for selecting the connection method is based on the pipe diameter, pressure rating, and maintenance requirements:

Welded connections (butt welding or socket welding): Suitable for high-temperature, high-pressure, and large-diameter pipelines, offering strong sealing performance. Threaded connections are suitable for small-diameter pipes, facilitating assembly and disassembly.

Flanged connections facilitate disassembly and maintenance at interfaces of large equipment.

Heat fusion connections are mainly used for PPR, PE, and other household and water supply pipes.

General principle: The larger the diameter and the higher the pressure, the more recommended it is to use welding or flange connections.

II. Installation Method of 45° Elbows

Preparation: Before installation, confirm that the elbow specifications, material, and pressure rating are consistent with the design. Check for cracks, dents, and deformation. The welding ends should be cleaned thoroughly.

1. Welding Installation Steps

First, determine the turning position of the 45° elbow to ensure accurate direction.

Assemble the joints and secure them with clamps. The misalignment should generally be controlled within 10% of the wall thickness or not exceeding 1 mm.

Perform spot welding for positioning. After confirming the direction is correct, proceed with formal welding.

Weld in layers to avoid welding defects such as slag inclusions and porosity.

After welding, perform pressure testing or non-destructive testing as required.

2. Precautions for Threaded, Flange, and Hot-Melt Installation

Threaded connections require wrapping with Teflon tape or sealant. Tighten, but not excessively, to avoid cracking.

For flange connections, the gasket should be centered, and bolts should be tightened evenly in a diagonal sequence.

Hot-melt installation temperature is generally between 250–260℃. After heating, insert to the designated depth; do not rotate before cooling.

III. Precautions During Installation

Minimize the number of bends to reduce pipe resistance and energy consumption.

If necessary, use two 45° bends instead of one 90° bend to mitigate fluid impact.

Fixed supports or thrust devices should be installed near bends to avoid stress concentration.

The distance between supports and bends should generally be more than twice the pipe diameter.

Air should be purged from the pipe before pressure testing.

IV. Typical Applications of 45° Elbows

45° elbows are typically used in pipelines where the directional change is minimal and pressure loss is desired. They are commonly found at pump outlets, water treatment systems, fire-fighting water supply systems, chemical pipelines, and corners in residential plumbing and electrical wiring.

Cangzhou Aosendike Pipe Fittings Manufacturing Co., Ltd. is a large-scale manufacturer specializing in elbows, tees, reducers, and pipe caps. We can produce according to ASTM, ANSI, JIS, DIN, GB, and other standards, covering virtually all types of steel.

For any purchasing needs or inquiries, please contact us.

Mobile: 86-13668807131

Website: https://www.authenticfitting.com/

Address: Mengcun Hui Autonomous County, Cangzhou City, Hebei Province

Email: authentic013@steelpipes-fitting.com