What is a Elbow Pipe? What is the purpose of a Elbow Pipe? In modern piping systems, elbows are a type of pipe fitting used to change the direction of a fluid. Elbows pipes are also divided into a variety of types depending on the material, angle and connection method. For example, 45-degree elbow, 90 degree elbow, 180 degree elbow and so on.
How Many Types of Elbow Pipes Are There
Classification of Elbow Pipe
Bending Angle – 45 Degrees, 90 Degrees, 180 Degrees
- 45 degree pipe elbow: This type of bend allows the pipe to turn slowly. It is best used where a smooth change of direction is required, such as water supply pipes in waterworks. Compared to right angle bends, it reduces the impact of water flow and makes the pump work easier. Many chemical plants use this type of elbow to transport chemical liquids.
- 90 degree pipe elbow: 90 degree is the most commonly used type of elbow. It allows the pipe to be turned directly at a right angle, and is especially suitable for installation in the corner of a wall or behind equipment. It is used in firefighting pipes at construction sites and fuel lines at gas stations. It’s important to note that this type of elbow can cause the flow of water to turn suddenly, so the pressure will drop a bit.
- 180 degree pipe elbow: This type of bend allows the pipe to turn around and go back. Often seen in boiler rooms to circulate hot water. Food factories also use this type of elbow because it is easy to clean. When you buy it, pay attention to the inner wall should be smooth and there should be no dead space.
Connection Methods
- Welded elbow: Welded elbows have properties such as high strength and are not prone to leakage. Petroleum pipelines, high-pressure steam pipe commonly used. But it is not easy to disassemble after welding. Welding personnel must hold a professional welding certificate.
- Threaded elbow: This type of bend is characterized by threads on both ends, which can be screwed on. Commonly used in home gas piping, installation and removal are very convenient. But can not be used in places with too much pressure, easy to leak. And need to wrap the sealing tape.
- Flange elbow: Flange elbow is the disk on both sides of the pipe, fixed with screws. Factory often have to dismantle the pipeline to use this pipe joints. In the installation should be aligned with the screw holes, the gasket should be placed correctly. This type of bend is more expensive, but it is the most convenient to use.
タイプ | Best Application Scenario | 定格圧力 |
Welded Elbow | High-pressure permanent systems | Up to 32.0 MPa |
Threaded Elbow | Gas pipelines requiring maintenance | Below 16 Bar |
Flanged Elbow | Frequent disassembly systems | ANSI Class 150-900 |
注釈
Pressure unit conversion: 1 MPa≈10 Bar.
ANSI Class stands for American Standard Pressure Rating System (Class 150≈20 Bar).
Gas pipes must be connected with NPT standard threads.
Flange connection must be used with the corresponding gasket.
How To Select Different Materials
- Stainless steel elbow pipe: non-rusting elbows are generally suitable for application scenarios such as hospitals and food factories.304 model stainless steel elbows as well as 316 stainless steel elbows are a few commonly used piping fittings. But it needs to be polished on the inside, and the surface should be checked for scratches.
- Carbon Steel elbow pipes: Carbon steel bend is the most cost-effective and is suitable for construction sites. But it has the disadvantage that it is easy to rust, and should be surface treated, for example, painting or galvanizing. Water pipes, heating pipes commonly used elbow pipe fittings of this material.
- PVC pipe elbows: lightweight and good installation and corrosion resistance, commonly used in chemical plants, such as the need for acid and alkali resistance of the harsh environment. But its disadvantage is that there can not be a long time of sunlight. Need to add UV protection agent in the pipe manufacturing process to maintain its performance.
アプリケーション・シナリオ
- Water supply and drainage system: carbon steel is often used. The outer diameter is 15 mm to 500 mm, and the wall thickness is 1 mm to 10 mm.
- Hvac system: Used for conveying cooling medium or air. The outer diameter is usually 50 mm to 2000 mm, and the wall thickness is 2 mm to 20 mm.
- 化学工業: Chemical piping systems require elbow fittings with excellent corrosion resistance. Common sizes are 100 mm to 500 mm in outer diameter and 5 mm to 15 mm in wall thickness.
