Table of Contents
“Pipe ends” refer to the two ends or openings of a pipe, which are typically processed to connect with other pipes, fittings, or components as needed. The treatment of the pipe ends varies depending on the type of connection required. Common types of pipe ends include Plain End (PE), Bevelled End (BE), Threaded End, Flanged End, Socket Weld End and Grooved End.
Sometimes, a pipe may have two different types of ends. The choice of pipe end type depends on the application requirements and the desired connection method.
Features:
- Smooth Ends: The pipe ends are not specially treated, maintaining a natural smooth state, making it easy to connect with other fittings.
- Simplicity and Ease of Use: The connection methods are relatively simple, commonly using welding, pipe clamps, or flanges.
- No Additional Processing Required: Since no bevel or threading exists, no additional end preparation is needed during installation.
- Cost-Effective: Plain ends have lower processing costs than other types of pipe ends that require additional processing (such as threading or beveling).
- Suitable for Low-Pressure Environments: This product is ideal for low-pressure or non-high-temperature applications, as the connection method is simple and the strength is relatively low.
Applications:
- Simple Connections: Plain end pipes are often used in piping systems where quick installation and disassembly are needed, particularly in environments where high-strength connections are not required.
- Low-Pressure Systems: Suitable for low-pressure and normal-temperature environments, especially for systems transporting water, oil, or gas.
- Temporary Piping Systems: Plain end pipes are commonly used in temporary piping installations or systems that require regular maintenance due to their ease of installation and removal.
- Welded Connections: These are ideal for applications where connections are made by welding, especially when the strength requirements are not extremely high.
- Non-High-Temperature Environments: Because of its simple structure and connection method, plain end pipes are more suitable for applications in environments with low temperatures or without special requirements.
Considerations:
Additional sealing materials (such as gaskets) may be required during connection to ensure a tight seal, especially in systems where leakage prevention is important.
Due to their lower strength, plain end connections are generally unsuitable for systems under high pressure, such as high-pressure pipelines.
Features:
- Strong Connection: The beveled end design provides a better welding joint, making the pipeline connection more robust and suitable for high-pressure and high-temperature environments.
- Good Weldability: The bevelled end offers enough welding area for the welding metal to penetrate the pipe joint more effectively, enhancing the strength of the weld.
- Reduced Stress Concentration: The beveled design helps alleviate stress concentration in the welded area, improving the durability of the welded joint.
Applications:
- Butt Welding Connections: Bevelled ends are commonly used for butt welding between two pipes or between a pipe and other components, especially in piping systems that need to withstand higher pressures and temperatures.
- High-Pressure and High-Temperature Systems: Due to the higher strength of the weld, beveled ends are frequently used in high-pressure and high-temperature systems such as those in the petroleum, chemical, power, and natural gas industries, ensuring the safety and long-term stability of the pipeline.
- Pressure Vessels and Boilers: Bevelled ends are also widely used in the piping connections of pressure vessels and boilers to ensure sufficient pressure resistance and sealability after welding.
Considerations:
- Welding Technique Requirements: When welding with beveled ends, strict control of the welding process is necessary to ensure that the weld quality meets standards and to avoid welding defects such as porosity, inclusions, or lack of fusion.
- Higher Cost: Compared to plain ends, beveled ends require more complex processing, resulting in a higher cost, especially in large-diameter pipes.
- Cleaning Before Welding: To ensure weld quality, the bevelled end must be thoroughly cleaned before welding to remove oil, rust, and other impurities that may affect the welding process.
Threaded End
Threaded End refers to a pipe end that is processed with threads, typically either internal or external, allowing it to be connected to other components or fittings that have matching threads. The threaded end connection method is usually simpler and faster, making it suitable for situations where welding or more complex connections are not required.
Features:
- Easy Installation: The threaded end connection method does not require welding or complex tools, allowing for a quick and easy installation process—connections are made simply by rotating the parts.
- Disassemblability: Threaded connections allow pipes and fittings to be easily disassembled, which is useful for systems that need regular inspection, maintenance, or replacement.
- Lower Cost: Compared to welding or other complex connection methods, threaded connections are less expensive, making them suitable for projects with stricter budget constraints.
Applications:
- Pipe Fitting Connections: Threaded ends are mainly used to connect pipes to fittings (such as elbows, tees, valves, etc.) via threaded connections. They are commonly found in low-pressure and ambient temperature pipe systems.
- Residential and Industrial Piping: Threaded ends are widely used in construction, water pipelines, gas transportation, and other piping systems, especially in residential or light industrial applications, due to their easy installation and convenient disassembly.
- Quick Installation and Disassembly: Threaded ends are ideal for systems that require rapid installation, maintenance, or replacement, as pipes or fittings can be easily connected and disconnected by rotating them.
- Small Diameter Pipe Systems: Since threaded connections have limited pressure-bearing capacity, they are typically used for smaller diameter pipes, especially in applications where pressure and temperature requirements are not high.
Considerations:
- Lower Pressure and Temperature Suitability: Threaded connections have a lower pressure-bearing capacity, making them ideal for low-pressure, ambient temperature systems. They are generally unsuitable for high-pressure or high-temperature pipeline applications.
- Sealing Issues: Threaded connections may face sealing problems, especially in high-pressure environments. Therefore, sealing materials (such as sealing tape or sealants) are often required to ensure leak-proof connections.
- Prone to Damage: Threaded ends are susceptible to damage from excessive tightening or impact during disassembly, which can affect the connection quality and the service life of the pipe.
- High Precision Required: The precision of the threading process is crucial for the connection quality. Any deviation in the threads can lead to loose connections or leaks.
Socket Weld End
Socket Weld End refers to a pipe end that is processed to create an internal recess, allowing it to be connected with socket weld fittings. In this connection method, the external end of the fitting is inserted into the pipe’s internal recess, and the two are welded together. This connection type is typically used for high-strength connections in small-diameter pipes.
Features:
- Strong Connection: Socket weld ends provide a robust welded connection that can withstand high pressure and temperature, making them suitable for high-demand industrial applications.
- Good Sealing: The welded connection eliminates seams at the joint, reducing the risk of leakage and ensuring excellent sealing.
- No Additional Fittings Needed: Socket weld connections do not require bolts or other fittings, simplifying the installation process and reducing the use of additional parts.
- High-Temperature Resistance: Due to the welded structure, socket weld connections can withstand high temperatures and pressures, making them ideal for the transmission of hot fluids.
Applications:
- Small Diameter Pipe Connections: Socket weld ends are commonly used for pipes with smaller diameters (typically 2 inches and below), especially in systems that need to withstand high pressure.
- High-Pressure Piping Systems: Due to the strong weld, socket weld ends are widely used in high-pressure, high-temperature piping systems, providing reliable sealing and strength.
- Complex Systems: They are suitable for pipe systems that require precise installation, ensuring stability at connection points, particularly in environments with high vibration or temperature fluctuations.
Considerations:
- Limited to Small Diameter Pipes: Due to the small insertion portion of the socket weld design, it is typically used for smaller diameter pipes, especially those under 2 inches.
- Requires Welding Expertise: Socket weld connections require specialized welding skills to ensure the quality of the weld, as poor welds may result in leaks or weak connections.
- Strict Installation Requirements: The fittings and pipes must be precisely aligned for proper insertion to ensure good contact during welding, avoiding issues like porosity or incomplete welding.
- Permanent Installation: Socket weld connections are permanent and cannot be disassembled once welded, making them suitable for systems that require long-term fixed installations.
Flanged End
Flanged End refers to a pipe end that is fitted with a flange or has been processed to include bolt holes, allowing it to connect to other flanged components through bolts. Flanged ends are a common and robust method of pipe connection, widely used in applications that require high-strength connections and good sealing properties.
Features:
- Flanged Connections: Flanged ends are used to connect pipes, fittings, valves, or equipment that have corresponding flanges, commonly found in industries such as petroleum, chemicals, power generation, water supply, and HVAC.
- High-Pressure and High-Temperature Environments: Due to their high strength and reliable sealing, flanged connections are suitable for high-pressure and high-temperature piping systems.
- Systems Requiring Disassembly or Maintenance: Flanged connections are easy to disassemble, making them ideal for systems that require regular maintenance, inspection, or pipe replacement.
- Large-Diameter Pipe Systems: Flanged ends are typically used in large-diameter pipes, as they provide a stable connection and can withstand greater mechanical loads.
Applications:
- Small Diameter Pipe Connections: Socket weld ends are commonly used for pipes with smaller diameters (typically 2 inches and below), especially in systems that need to withstand high pressure.
- High-Pressure Piping Systems: Due to the strong weld, socket weld ends are widely used in high-pressure, high-temperature piping systems, providing reliable sealing and strength.
- Complex Systems: They are suitable for pipe systems that require precise installation, ensuring stability at connection points, particularly in environments with high vibration or temperature fluctuations.
Considerations:
- Sealing During Installation: It is essential to ensure the proper installation of the gasket during the flange connection to avoid leakage, especially in high-pressure and high-temperature applications.
- Bolt Tightening: Flanged connections rely on the tightening force of bolts. During installation, bolts should be tightened evenly to prevent instability or leakage caused by over-tightening or under-tightening.
- Higher Cost: The processing and installation of flanged ends are more complex, especially for large-diameter pipes, making them more costly than simpler welding or threaded connections.
- Installation Environment Requirements: Installing flanged connections requires precise alignment to ensure the proper alignment of the flange faces and bolt holes, which is crucial for maintaining the connection’s sealing and strength.
Grooved End
Grooved Pipe refers to a type of pipe whose ends are specially processed, typically through machining or groove-rolling techniques, to form a circular groove (i.e., “groove”) on the outer surface of the pipe. This groove design is intended for connection with specialized fittings (such as grooved joints, couplings, or pipe fittings), commonly used in piping systems that require quick installation, disassembly, or adjustment.
Features:
- Groove Design: The ends of the pipe are machined to create one or more circular grooves, which are used to connect to corresponding grooved fittings (such as grooved joints, couplings, etc.).
- No Welding Required: Connections in a grooved pipe system typically do not require welding or bolts, but instead are made by inserting the grooved joint and securing it with specialized couplings, offering quick and convenient installation.
- Suitable for Large-Diameter Pipes: Grooved pipe connections are particularly suitable for large-diameter pipes, especially in environments that require fast installation or replacement.
Applications:
- Fire Protection Systems: Grooved pipes are widely used in fire protection systems, especially in sprinkler systems, due to their easy installation and adaptability to changes in the system.
- Industrial Piping Systems: In some industrial environments, grooved pipes are also used in water, steam, and air distribution systems, facilitating the rapid installation and disassembly of piping.
- HVAC Systems: Grooved pipes are commonly used in Heating, Ventilation, and Air Conditioning (HVAC) systems, providing flexible pipe connections and system expansion capabilities.
Considerations:
- Scope of Use: Grooved pipes are suitable for low to medium-pressure piping systems and may not be as robust as welded or threaded connections in high-pressure systems.
- Maintenance Requirements: Although grooved connections are convenient, regular checks on the couplings and joint seals are necessary to ensure stable connections.
- Durability: The durability of grooved pipes depends on the quality of the joints and couplings used, so selecting appropriate materials is crucial.
Comparison of Pipe Ends
This table summarizes the key features, applications, advantages, and considerations for each type of pipe end, helping you make informed decisions based on system requirements and installation needs.
| Pipe End Type | Description | Application | Advantages | Considerations |
| Plain End (PE) | The pipe end remains smooth with no special treatment, suitable for simple connections. | Suitable for welding, clamping, and other simple connections, typically used in low-pressure, ambient temperature environments. | Simple installation, low cost, and wide applicability. | Suitable for lower pressure and temperature systems, requires additional connection treatments. |
| Bevelled End (BE) | The pipe end has a bevel at a certain angle for butt welding. | Suitable for butt welding, typically used in high-pressure, high-temperature systems. | Provides a strong welding connection, suitable for high-pressure and complex systems. | Requires precise welding technique, suitable for medium to high-pressure systems. |
| Threaded End | The pipe end is threaded for threaded connections. | Suitable for low-pressure, ambient temperature applications, such as residential or light industrial pipelines. | Quick and easy installation, removable, suitable for rapid connections. | Suitable only for low-pressure systems, prone to thread damage, requires sealing materials. |
| Flanged End | The pipe end has a flange installed or pre-drilled for bolting to other flanged components. | Suitable for high-pressure, high-temperature systems, large-diameter pipeline connections, and situations requiring disassembly and maintenance. | High-strength connection, excellent sealing, suitable for large-diameter and high-pressure systems. | Higher cost, requires precise alignment, installation requires attention to sealing. |
| Socket Weld End | The pipe end is prepared for socket weld fittings, suitable for socket welding connections. | Suitable for small-diameter, high-pressure pipelines, particularly in high-temperature environments. | Provides strong, reliable welding connections with good sealing. | Suitable only for small-diameter pipes, requires precise fitting, not removable after installation. |
| Grooved End | The pipe end is designed with a groove for connection with grooved fittings and couplings. | Commonly used in fire protection systems, HVAC, and industrial systems requiring quick installation and flexibility. | Quick installation, no welding required, suitable for large diameter pipes. | Not recommended for high-pressure systems, requires specific grooved fittings. |
