Elbow fittings, as key connectors in pipeline systems, play an irreplaceable role in various fluid transportation fields. They can change the direction of the pipeline, allowing the fluid to flow smoothly along a predetermined path, and realize the diversification and complexity of pipeline layout. Elbow fittings are widely used in pipeline systems. Their common specifications and models can be classified mainly from the following aspects:
1. Divided by angle
45-degree elbow: It is mainly used in situations where the pipe needs to change direction more gently, such as in the building water supply and drainage system, when the drainage pipe needs to avoid obstacles and make a small angle turn. It can reduce the pressure loss in the pipe system and improve the flow efficiency.
90 degree elbow: a common type of elbow, widely used in various piping systems. For example, in indoor water supply pipes, it changes from horizontal to vertical to supply water to each floor, or in fire protection pipe systems, it allows pipes to make right-angle turns along the building structure. It is usually used in piping systems where a stricter bending angle is required, such as when other pipe equipment needs to be connected before or after the elbow.
180 degree elbow (U-elbow): used for special pipe layout, such as in the circulating refrigeration system of some chemical equipment, so that the liquid can flow in the opposite direction to achieve better refrigeration effect. Due to its very large bending angle, it is usually only used in a few cases.
30-degree elbow: Usually used in piping systems where a small turn is required, it can change the flow direction of the pipeline and reduce pressure loss in the system.
60 degree elbow: usually used in piping systems where medium-amplitude turns are required, which can also change the flow direction of the pipeline and reduce pressure loss.
2. Classification by pipe diameter (measured by nominal diameter DN)
Small-caliber elbows: including DN15, DN20, DN25 and other specifications. These specifications of elbows are often used in household water supply and drainage systems, small heating systems, etc. For example, DN15 elbows are usually used to connect pipes of small water-using equipment such as faucets.
Medium-caliber elbows: such as DN32, DN40, DN50, DN65, DN80 and other specifications, are used in general building water supply and drainage main pipelines, some material conveying pipelines in industrial production, etc. For example, a DN50 elbow may be used to connect the main drainage pipes between units of a building.
Large-diameter elbows: such as DN100, DN125, DN150, DN200 and above specifications, are mainly used in large-scale industrial pipeline systems, such as crude oil pipelines in petrochemicals, urban water supply mains, etc.
3. Classification by curvature radius
Long radius elbow (R=1.5DN): Its advantage is that the resistance when the fluid passes through is relatively small, and it is suitable for occasions with high requirements for fluid delivery efficiency. For example, in large air-conditioning chilled water pipe systems, long radius elbows are often used to reduce the head loss of the water pump.
Short radius elbow (R=1.0DN): It is widely used in situations where space is limited, such as in pipe connections inside some compact industrial equipment, or at pipe bends in narrow spaces inside buildings.
4. Other common models
Tee elbow: a pipe fitting used to divide a pipe into two pipes or merge two pipes into one pipe. It has many different types of forms, such as equal-diameter tees, reducing tees, unequal-angle tees, etc.
Reducing elbow: A pipe fitting used to connect two pipes of different diameters. It can make the two pipes transition smoothly and avoid pressure loss during the transition process.
Same diameter elbow: a pipe fitting used to change the flow direction of a pipe. Unlike other elbows, the same diameter elbow only changes the direction of the pipe without changing the diameter of the pipe.
Socket weld elbow: It is usually a pipe fitting made by welding two pipes of different sizes together. It can be used in the piping system to connect pipes of different diameters and materials, and can be replaced when disassembly is required.
In summary, elbow fittings come in a variety of specifications and models, and choosing the right elbow is crucial to the performance and life of the piping system. When purchasing elbows, you should choose a regular manufacturer（Permanent Steel Manufacturing Co.,Ltd）based on the specific use environment and medium requirements to ensure product quality.
Read more: Types of Elbow Fittings in Piping
