Bi pipe

Types

Bi pipe refers to bellows isolating pipes or bellowed pipes. They feature a flexible bellow section, which helps absorb vibrations or thermal expansion in the piping system, preventing damage to equipment or stress on the piping. This unique design allows them to be effective in various industrial applications.

Materials

Bi pipes come in different materials, each suitable for specific environments and applications. The common materials include:

• Stainless steel: Stainless steel bi-pipes are highly resistant to corrosion, making them ideal for chemical and marine environments. The durability and strength of stainless steel also ensure that the pipe can withstand high pressure and temperature.
• Carbon steel: Carbon steel bi pipes offer high strength and are used in many industries due to their balance of cost-effectiveness and mechanical properties. While carbon steel is prone to corrosion, it can be coated or lined with other materials to prevent rust in adverse environments.
• Alloy steel: Alloy steel bi pipes are suitable for extreme temperature and pressure conditions due to their enhanced properties. Common alloys include chrome-moly and nickel alloys, which are suitable for high-temperature and low-temperature service.
• PTFE-lined bi pipes: PTFE-lined bi pipes are effective in preventing corrosion and are used in piping systems where the transported media are highly corrosive. The PTFE lining provides a barrier against chemical attack while maintaining the flexible bellow's functionality.

Sizes

Bi pipes come in various sizes to accommodate diverse industrial needs. These include:

• Standardized sizing: Bi pipes are based on standard pipe size conventions, such as nominal pipe diameter (NPD) in inches or millimeters. This ensures compatibility with existing piping systems in most industries.
• Diameter ranges: Bi pipes typically come in diameters ranging from 0.5 inches to 48 inches, depending on the application. Industrial systems require larger diameters, while smaller installations and specialized systems use smaller diameters.
• Custom sizes: Custom-sized bi pipes are also available for specialized industries. These pipes are fabricated in unique lengths, diameters, and bellow configurations to meet specific design requirements.
• Length specifications: Standard lengths of bi pipes usually range from 10 to 20 feet. However, custom lengths can be fabricated to fit specific installations without the need for additional joints or welds.

Industry applications

Bi pipes are a critical component in many industrial systems. Their flexibility and ability to absorb shocks and vibrations allow effective operation in various applications. Here are a few common uses of bi pipes:

Refineries

• Catalytic cracker units: These units operate under severe service, characterized by intense heat, heavy vibrations, and rapid chemical reactions. Bi pipes' flexibility and robustness make them ideal for such environments, as they absorb vibrations, reducing the risk of cracks or leaks in the piping system. This enhances the unit's stability and prolongs its lifespan. They ensure smooth operation, minimising downtime for repairs.
• Hydrocracker and fluid catalytic cracking units: Hydrocrackers and fluid catalytic cracking units have extreme temperature, pressure, and corrosive chemicals. People often install bi pipes in these units to withstand the environment's harsh conditions. The bi pipes maintain the integrity of the fluid transfer system, preventing costly breakdowns or safety hazards.
• Delayed cokers: Delayed cokers feature many thermal cycles and mechanical stresses due to heavy oil conversion into petroleum coke. The flexible bellow section of bi pipes effectively absorbs these shocks, minimising stress on the surrounding infrastructure. This not only increases the durability of piping systems but also improves operational efficiency, as smoother pipelines facilitate better fluid flow.

Petrochemical plants

• Production and processing units: Bi pipes are an indispensable part of production and processing units. The bi pipe's ability to handle temperature fluctuations and pressure variations makes it an ideal component in this volatile environment. That's why people often use them in transporting gases, liquids, and chemicals during the production of essential petrochemical products.
• Vibrating equipment: People often install bi pipes in equipment that generates a lot of vibrations, such as compressors and pumps. The bellow in bi pipes dampens these vibrations, reducing wear and tear on the machinery. This not only improves the lifespan of the equipment but also enhances operational efficiency, as reduced vibrations lead to smoother operations.

Power generation

• Gas turbines: People install bi pipes in gas turbines to connect various sections while allowing for movement due to expansion and contraction. The bellow isolates vibrations from the turbine, which is critical in maintaining the stability of the surrounding piping system. This prolongs the lifespan of the pipeline infrastructure and reduces maintenance costs in power plants that rely on gas turbines for electricity generation.
• Steam power plants: In steam power plants, thermal expansion is a significant concern, especially in high-pressure steam lines. Bi pipes effectively mitigate these expansions, preventing damage to the piping system. Besides, they act as a buffer between the high-energy system and the building infrastructure, minimizing the transfer of vibrations that could be detrimental to sensitive equipment.
• Heat exchangers: Heat exchangers experience fluctuating temperatures and pressures, which can be harmful to the piping system. Bi pipes are commonly used to connect heat exchangers to the main piping system. They not only accommodate expansion but also protect the surrounding infrastructure from vibrations.

Natural gas processing

• Compressors: Bi pipes are commonly used in natural gas compression systems. They connect compressors to the piping system, accommodating the vibrations generated during gas compression. This vibration isolation protects the pipeline infrastructure from damage. By absorbing these shocks, bi pipes ensure the integrity and longevity of the entire gas handling system.
• Gas plants: Bi pipes transport natural gas and its associated liquids in gas processing plants. They are particularly useful in pipelines carrying wet gas, as the bellow can accommodate any resulting fluctuations in pressure and temperature. This adaptability minimizes the risk of leaks, ensuring safe operation in gas processing facilities.

Product specifications and features

Bi pipes have various components and features that offer distinct benefits to potential buyers. Understanding these specifications can help one ensure the bellowed pipe is ideal for their industry.

Key specifications

• Temperature range: Most bi pipes are designed to operate at temperatures ranging from -200°C to 1000°C. High temperature bi pipes are ideal for applications like furnace and reactors. Low temperature bi pipes are suitable for cryogenic processes.
• Length: Bi pipes are available in standard lengths of 1-6 meters. Buyers looking to suit unique applications can get custom lengths.
• Connection type: Bi pipes come with several connection possibilities. These include flanged ends, welded ends, and threaded ends. Each of these connection types offers distinct benefits. For instance, welded ends provide a permanent connection, while flanged ends allow easy disassembly.
• Pressure ratings: Most bi pipes come with pressure ratings between PN10 and PN40. Higher ratings are suitable for engineering systems that operate at high pressure. Lower ratings are compatible with systems that need basic pressure capability.

Key features

• Anti-corrosiveness: Many bi pipes are manufactured using stainless steel and alloy steel. As stated earlier, these material types are resistant to adverse corrosive conditions. This makes the bellowed pipes suitable for chemical processing, marine, and other outdoor applications.
• Flexibility: Bi pipes feature a flexible bellow section. This enables them to absorb vibrations and thermal expansion. The degree of flexibility usually depends on the material.[3]
• Efficiency: Many modern Bi pipes have a streamlined internal design. They enable smooth fluid flow, which reduces friction and ensures efficient transfer of gases, liquids, or steam.
• Durability: Most bi pipes are fabricated using heavy-duty materials. These pipes can withstand extreme temperatures, pressures, and vibrations. This ensures longevity even in harsh industrial environments.

How to choose bi pipe

The bellows isolating pipe is an important component in any mechanical system that requires fluid or gas transfer. When choosing a bi pipe, there are several factors buyers must consider. These factors will help ensure they get a bellowed pipe that fits the conditions of their mechanical systems.

Operating conditions

Buyers should consider the temperature, pressure, and type of fluid, gas, or steam their systems are transferring. For instance, high-pressure systems require bi pipes with greater pressure ratings. Likewise, corrosive environments need bi pipes fabricated from corrosion-resistant materials like stainless steel.

Flexibility and movement

The primary role of bi pipes is to absorb mechanical vibrations and thermal expansion. That’s why buyers should consider the amount of expansion or contraction the system experiences. This will help ensure they get a bellow section that offers the necessary flexibility.

End connections

Buyers should look for bi pipes with end connections that match existing piping systems. Common connection types include welded, threaded, or flanged connections. Each of these connection types offers unique benefits. For instance, flanged connections allow for easy disassembly, while welded connections provide a strong, permanent bond.

Specifications

Buyers also have to consider the material and size specifications of the bi pipes. Generally, stainless steel bi pipes are ideal for adverse conditions. Meanwhile, carbon steel bi pipes are cost-effective options in non-corrosive environments. Besides, they should ensure the bellow design of the bellowed pipe is compatible with the unique needs of their industrial systems. Such considerations range from the length and diameter of the pipe to the type of bellow.

Quality and standards

Buyers should prioritise bi pipes that meet industrial quality standards. People often certify these pipes in accordance with API, ASME, or ANSI guidelines. Moreover, they should source these pipes from reputable suppliers with consistent quality and reliable customer service. This will help ensure they get durable bi pipes that offer effective performance in the long run.

Q & A

Q. What's the role of the bellow in a bi pipe?

As mentioned earlier, the bellow in a bi pipe is designed to accommodate movement. Moreover, it provides flexibility to the piping system. This is particularly useful when the system experiences thermal expansion or mechanical vibrations. Without the bellow, the piping system would be rigid. This would lead to stress and potential failure of the pipes or connected equipment.

Q. What industries benefit from bi pipes?

Various industries benefit from bi pipes. Petroleum refining and chemical processing industries use these pipes to transport fluids and gases. Power plants also use the pipes in operations like steam generation and gas compression. Marine engineering and construction also install these pipes in their systems. Plus, people in HVAC systems and high-vibration environments like manufacturing plants often use bi pipes to minimize the transfer of vibrations.

Q. Are bi pipes customizable for specific industrial needs?

Yes, bi pipes are customizable. Buyers can get bi pipes in various lengths, diameters, and material types. They can also customize the bellow design depending on their vibrations, thermal expansion, and misalignment requirements. Moreover, they can request specific end connections and configurations.

Q. How can one ensure the longevity of bi pipes?

People can ensure the longevity of bi pipes by regularly inspecting and maintaining them. The maintenance practices to uphold this longevity include monitoring for signs of wear, corrosion, or fatigue. They should also replace any damaged bellow sections promptly to avoid further degradation. Besides, regular cleaning of the pipes and ensuring they are free from residue build-up. This will help enhance effective flow and reduce pressure on the bellow.

Q. Can bi pipes handle high-pressure conditions?

Yes, some bi pipes can handle high-pressure conditions effectively. However, this depends on the material and design of the pipe. Pressure rating is among the key specs buyers should consider when purchasing bi pipes. These pipes are fabricated from stronger materials like alloy steel. These pipes are also designed to withstand extreme pressure.