A bellows forged steel manifolds is a high-pressure pipe fitting flexibly combined with a forged steel manifold. It uses flanges or butt welding connections and can be equipped with quick couplings, making installation and maintenance convenient. It is widely used in pipeline systems under harsh conditions such as petroleum, chemical, and power industries.
Based on the name “bellows forged steel manifolds,” we can deepen our understanding of it from three aspects:
• Bellows pipe: A bellows pipe is a cylindrical, thin-walled, bellows shell with multiple transverse corrugations. Its thin wall provides high sensitivity. As a measuring element in pressure measuring instruments, it converts pressure into displacement or force, with a measurement range from tens of Pascals to tens of megapascals. Bellows pipes can be classified by material into metal bellows pipes and plastic Bellows pipes. Metal bellows pipes are used to compensate for pipeline thermal deformation, dampen vibrations, and absorb pipeline settlement deformation; plastic bellows pipes are widely used in media transportation and power wiring.
• Forged steel: A type of steel that has undergone forging. Pressure is applied to a metal billet, causing plastic deformation to obtain forgings with specific mechanical properties, shapes, and dimensions. Compared to ordinary steel, forged steel has a denser internal structure and finer grains, resulting in better strength, toughness, and wear resistance, and the ability to withstand greater pressure and loads.
• Manifold: In the automotive industry, a manifold typically refers to either the intake manifold or the exhaust manifold. The intake manifold is located between the throttle valve and the engine’s intake valves, and its function is to evenly distribute air, fuel-air mixture, or clean air to each cylinder. The exhaust manifold connects the engine’s cylinders and the exhaust system, primarily responsible for collecting the exhaust gases emitted after combustion in each cylinder and guiding them into the exhaust pipe.
The forged steel part has high strength and high pressure resistance, while the bellows pipe has the ability to withstand temperatures of -196~600 ℃, corrosion resistance, and flexibility to compensate for displacement. The combination of the two ensures the rigidity of the pipeline, absorbs thermal expansion and contraction and vibration, and reduces stress concentration.
Components of a Forged Steel Bellows Manifold
Bellows Section
- Double-layer bellows: One of the core components, typically featuring a double-layer design. This design offers excellent flexibility, adapting to various vibrations and displacements during vehicle operation, and also provides a buffering effect, reducing damage to the manifold caused by vibration.
- Expansion joints or mesh sleeves: Some bellows have expansion joints or mesh sleeves added internally. Expansion joints further enhance the bellows’ expansion and contraction performance to better cope with thermal expansion and contraction; mesh sleeves help improve noise reduction, allowing exhaust gases to pass through these special structures and reducing noise generation.
- Wire mesh sleeve: Wrapped around the double-layer bellows, protecting and reinforcing the bellows.
- Clamping rings: Located on the straight edges at both ends of the bellows, ensuring the stability of the connection between the bellows and other components.
Manifold Section
- Manifold body: Made of forged steel, it is the main channel for collecting and distributing fluids (such as exhaust gases from a car engine).
- Interfaces: The manifold has interfaces for connecting to other components, such as engine cylinders or exhaust pipes.
Other Possible Components
- Valves: Some industrial bellows forged steel manifolds may be equipped with valves to control fluid flow, pressure, or direction. For example, stainless steel bellows gate valves may be built into bellows steam distribution bundles to eliminate packing leakage.
- Base Brackets: For some bellows forged steel manifolds that require fixed installation, base brackets are provided.
Installation Locations
1. Junction of Main and Branch Pipes
The forged steel manifold body is directly welded to the main pipeline or flanged, serving as a branch interface; the bellows pipe section flexibly connects to the branch pipe, absorbing displacement caused by thermal expansion and contraction or equipment vibration, and avoiding stress concentration.
2. Near Equipment Inlets/Outlets or Pump/Valve Assemblies
When the manifold is used to connect moving equipment such as compressors, pumps, and heat exchangers, the bellows pipe section is arranged close to the equipment flanges, compensating for axial/lateral displacement during equipment operation and reducing the transmission of vibration to the main pipeline.
Maintenance Methods
Daily Inspection
Visually inspect the bellows surface for scratches, dents, rust, or leaks every shift. Use soapy water or a leak detector to check the airtightness of welds, flanges, and threaded connections. Address any bubbles or alarms immediately.
Cleaning and Corrosion Prevention
After shutdown, depressurize first, then use dry, oil-free compressed air to blow away dust, condensate, or process residues from the inside of the bellows. Clean the outer surface with a neutral detergent, rinse with clean water, and dry thoroughly. If rust spots appear, polish to a metallic shine and then apply a heat- and corrosion-resistant coating.
Lubrication and Sealing
Apply a small amount of high-temperature grease to the contact surfaces between the bellows and the movable supports or guides to reduce friction and wear. Inspect and tighten the flange bolts. If gaskets are found to be aged or unevenly indented, replace the gaskets immediately and tighten them evenly in a diagonal sequence.
Displacement and Stress Monitoring
Measure the free length of the bellows quarterly using calipers and compare it with the original installation data. If the elongation or compression exceeds 80% of the design compensation, the system should be stopped and the piping support system inspected. Use a laser alignment instrument or dial indicator to check the parallelism and coaxiality of the flanges at both ends of the bellows; if the deviation exceeds 0.1 mm, readjustment is required.
Replacement and Scrapping
When the bellows develops cracks, perforations, or wall thickness reduction exceeding the design allowance, the entire section must be replaced; partial welding repair is strictly prohibited. Record the batch number and installation date during replacement, establish a lifespan record, and reassess before the next maintenance cycle.
VMV’s “Steam Distribution Manifold” integrates all necessary components (steam traps, manifolds, valves, etc.). All components are mounted on a base bracket, with the manifolds scientifically distributed on both sides, forming a compact, easily disassembled, centralized positioning assembly. The main body is made of A105 forged carbon steel, with a dense structure, suitable for high-pressure chemical pipelines and pipeline heating. If Newton‘s steam distribution manifold meets your expectations, please feel free to contact us.
