Types of pipe reducers

Pipe reducers, also known as "big and small heads", are pipe connectors used to connect pipes of different diameters or wall thicknesses. They are usually made up of two pipes of different specifications. They are also divided into concentric reducers and eccentric reducers. Reducers can ensure that the connection between pipes is tight and firm, avoid leakage and rupture of pipes, and also improve the flow performance of the pipeline system.

Types of pipe reducers:

Depending on different connection methods and materials, reducers can be divided into many types. The following are several common types of reducers:

1. According to the connection method, reducers can be divided into butt-welded reducers, socket-type reducers, flange reducers, clamp reducers, etc.
2. According to the material classification: reducers can be divided into stainless steel reducers, carbon steel reducers, copper reducers, aluminum reducers, etc.
3. According to the pipe diameter classification: reducers can be divided into large-diameter reducers, small-diameter reducers, etc.
4. According to the shape of the pipe fittings: reducers can be divided into circular reducers, rectangular reducers, square reducers and rectangular connecting pipes with twisting direction.
5. According to the structure classification: reducers can be divided into concentric reducers and eccentric reducers.

(Circular reducers and square reducers are prone to concentric and eccentric diameters, while rectangular reducers only produce single-sided deflection and double-sided deflection)

The difference between eccentric reducers and concentric reducers:

1. Concentric reducer: The center lines of the two ends of the concentric reducer coincide, and the pipes are concentric. Concentric reducers are characterized by simple structure and low manufacturing cost, and are suitable for low pressure, low temperature and small flow occasions. It is often used in chemical, petroleum, power and other industrial fields where the flow direction and speed of the fluid need to be maintained.

2. Eccentric reducer: One end of the eccentric reducer is aligned with the center line of the pipe, and the other end is offset. The characteristic of eccentric reducers is that the direction of fluid flow changes little, and they are suitable for high pressure, high temperature, and large flow situations. They are often used in water supply and drainage systems where the direction of fluid flow needs to be changed or the flow rate needs to be reduced or increased.

Others:

3. Combined reducers: Combined reducers combine two pipes of different diameters into one pipe. They are suitable for situations where two fluid flows need to be combined, and are often used in pipe branches and confluences.
4. Diverter reducers: Diverter reducers have multiple diversion ports on a pipe to divert the fluid into different pipes. They are suitable for situations where the fluid needs to be distributed to different areas, and are often used in water supply and gas supply systems.

Manufacturing method of pipe reducers:

(1) Under normal circumstances, the roundness of pipes of different diameters of reducers should not exceed one percent of the outer diameter of the corresponding end, and the allowable upper and lower deviations are 3 mm. The manufacturing method of reducers is selected by user requirements and national standards.
(2) The commonly used forming processes are reducing and pressing, expanding and pressing, or reducing and expanding. For some specifications of reducers, stamping can also be used.

‌a. Reducing forming‌
Put a tube blank with the same diameter as the large end of the reducer into the forming die, and press along the axial direction of the tube blank to make the metal move along the die cavity and shrink to form. According to the size of the reduced diameter of the reducer, it is divided into one-time pressing forming or multiple pressing forming‌.

‌b. Expanding forming‌
Use a tube blank with a diameter smaller than the large end of the reducer, and use an internal punch to expand the inner diameter of the tube blank. The expansion process mainly solves the problem that the reducer with a large diameter is not easy to be formed by reducing the diameter. Sometimes, according to the material and product forming requirements, the expansion and reduction methods are combined. ‌

‌c. Stamping forming‌
For some specifications of reducers, the steel plate stamping forming process can be used for production. The shape of the die used for stretching is designed with reference to the inner surface size of the reducer, and the steel plate after cutting is stamped and stretched by the die.

Functions of pipe reducers:
1. Transitional connection
Reducers can connect two pipes of different diameters to achieve transitional connection, so that the pipeline system presents a variety of different diameters and flow characteristics. This connection method is suitable for chemical, oil pipeline and other fields.

2. Pressurization effect
When the pipeline needs to be pressurized, a reducer can be used to connect, and the flow rate can be increased by reducing the cross-sectional area, thereby achieving a pressurization effect. This connection method is suitable for water pump stations, water pipelines and other fields.

3. Diversion effect
In the pipeline system, due to the needs of different working conditions, the flow needs to be diverted to different pipes for processing. At this time, the large-diameter end of the reducer can divert multiple small-diameter pipes to achieve a diversion effect. This connection method is suitable for chemical, water treatment and other fields.

Application scenarios of pipe reducers:

The main purpose of the reducer is to make a diameter transition at the pipe connection to ensure the continuity and stability of the fluid flow. Reducers are widely used in various industrial pipelines, building water supply, hot water, heating, air conditioning, fire protection, chemical, shipbuilding, machinery and other fields. The following are several common application scenarios:

1. High-pressure pipeline system: such as high-pressure pipeline systems in the fields of petroleum, chemical industry, and electricity.
2. Food, medicine, bioengineering and other industries: These industries have relatively high requirements for pipeline connections. The application of reducers can avoid air leakage and foreign matter contamination in the pipeline.
3. Firefighting system: In the fire water pipe network, reducers can connect fire water pipes of various diameters to achieve rapid access to fire water sources.
4. Sewage treatment system: In the sewage treatment system, reducers can connect sewage pipes and treatment equipment to reduce water leakage and leakage during sewage treatment.

How to choose a pipe reducer?

Choosing a suitable reducer can reduce the probability of problems in the pipeline system. The following are some suggestions for choosing a reducer:

1. Select the material and connection method of the reducer according to the use environment and requirements of the pipeline system.
2. Select a suitable reducer according to the diameter and wall thickness of the pipe.
3. Select a suitable reducer according to the working pressure and temperature requirements.

In short, as a kind of pipe fitting, pipe reducer has high connection strength and sealing performance, and is widely used in pipeline systems in chemical, shipbuilding, petrochemical and other industries. Understanding the basic knowledge of reducers is important for pipeline connection and maintenance. In actual application, it is necessary to select appropriate reducers according to specific circumstances to avoid problems such as pipeline leakage.

Read more: Pipe reducer size selection or American standard pipe reducers