PIPE BENDS

It is a curved section of a pipe that changes the direction of the flow in a pipe when there is a pipe bend. The purpose of a pipe bend is to redirect the flow of liquids or gases from one direction to another, such as water, oil, gas, or steam, using a pipe bend.

Pipe bends are available in a wide range of sizes and angles, and they can be manufactured from a variety of materials, including metals such as steel, copper, and aluminum as well as plastics such as PVC and CPVC. The most common types of pipe bends are 45-degree bends, 90-degree bends, and 180-degree bends, but there are many other angles that can be made as well.

In order to make a pipe bend, either a straight section of pipe can be bent or two straight sections of pipe can be welded together at an angle by welding two straight sections together. It is important to remember that the choice of manufacturing method will depend on the material being used, the angle and radius requirements, and the requirements of the application. It has been found that pipe bends are used in a wide range of industries, such as oil and gas, chemical processing, power generation, and water treatment, to name a few.

It is important to note that the production of high-quality bends is largely relying on the manufacturing process of the steel pipe that is transformed into the bend.

In addition, the chemical composition of the pipe must also be chosen in order to ensure that the material properties of the pipe can be recovered once the bending process has been completed. In order to obtain the required hardness and mechanical properties, alloying elements can be added to the steel in order to ensure that the bend’s chemistry matches as closely as possible that of the line pipe’s chemistry, depending on the pipe dimensions, grades, and final bending conditions. Alloying elements can be added to the steel depending on the pipe dimensions, grades, and final bending conditions.

Each bend undergoes heat treatment in order to be able to achieve the required mechanical properties after it has been bent. When it comes to critical applications, such as high-strength steel, heavy walls, sour service, or low-temperature applications, we also perform full quenching and tempering after bending and consider that the best option.

As a result of the machining of the bend ends, we guarantee that the inside diameters of the bend will have optimum tolerances, as we make sure that the bend has at least the minimum working tolerances of the mother pipe.

Most pipe-bending methods fall into one of two categories:

• Cold bending
• Hot bending

In cold bending, the pipe is bent using sheer physical force, while in hot bending, heat is used to reduce the force needed.

The degree of bending possible and the final shape of the pipe are determined by the method.

COLD BENDING METHODS

Rotary Draw Bending:

Rotary draw bending involves the use of dies and other various components that work together to bend pipes or tubes in a rotary motion. This action draws the pipe or tube forward, creating the desired bend.

Mandrel Bending: 

In tubes and pipes with thinner walls, a mandrel is placed inside the bend to prevent defects such as rippling, flattening, and collapse from occurring.

Compression Bending: 

A stationary die bends a pipe or tube while a counter die bends the material around it.

Roll Bending: 

To achieve large radius bends or curves, this method passes a piece of pipe or tube through three rollers in a pyramid configuration.

HOT BENDING OR INDUCTION BENDING

Almost all hot pipe bending methods are induction-based, although there are slight differences.

The pipe is precisely heated using an induction heating coil before pressure is applied to bend it.

It requires much less physical force than cold bending methods and produces bends of similar or higher quality without using filler materials, mandrils, or other additives.

Despite minimizing diameter reduction at the bend site, induction bending alters pipe thickness in some ways.

Intrados — or the inner section of the bend — will typically become thicker while extrados — or the outer section of the bend — will become thinner.

Large-diameter piping and tubing, along with long-radius bends, are the most common applications for this method.

However, it also has uses in smaller piping diameters and short radius bends.

PIPE BEND SIZING 

In most cases, pipe bends are measured in relation to the nominal pipe size or diameter (D).

A long radius elbow, for example, has an end-to-center dimension 1.5 times the diameter (sometimes referred to as >1.5D).

Short-radius elbows feature an end-to-center dimension equal to the pipe diameter.

By multiplying the diameter of the pipe by the D designation, you can determine the radius of the centerline of bent pipes and tubes.

For example, a 5D pipe with a 10-inch D will have a centerline radius of 50 inches.

For 180-degree Pipe Bends, the center-to-center measurement is used to determine the space required and how the pipe bends will fit into the system.

The center-to-center dimension of 180-degree pipe bends can be calculated by multiplying the diameter by the D designation.

Short-radius 180-degree pipe bends are 2D while long-radius pipe bends are 3D.

A 4-inch pipe with a short radius bend would have a center-to-center dimension of 8 inches, whereas the same 4-inch pipe with a long radius bend would have a center-to-center dimension of 12 inches.

Whether its elbows or 180-degree bends, the tangent ends of induction bent pipe can be matched to existing piping by diameter, flange, valve, or fitting specifications.

Even though fitting and sizing bent pipes might seem complex at first, a basic understanding of the measurements used makes integrating them into a new design straightforward.

POPULAR MATERIALS USED FOR PIPE BENDING

Pipe bending methods will vary based on the metals used.

Due to the reduced force required to obtain common angles, induction bending is compatible with a wide range of ferrous and non-ferrous materials, including

• Steel & steel alloy pipes
• Stainless steel pipes
• Aluminum pipes
• Copper pipes
• Nickel pipes,

Pipe Fittings Dimensions Tolerance 

 Radius Table of Long Radius Bends