In the petrochemical industry, metal hoses are an extremely important flexible connector for connecting different parts in a fixed piping system to accommodate various dynamic conditions such as thermal expansion and contraction, vibration, displacement, and external stresses. Metal hoses must be designed and selected for materials that can withstand the harsh conditions common in petrochemical environments, including high temperatures, high pressures, corrosive media, and potential explosion risks. Here are some key points about metal hoses in the petrochemical industry:
Construction and Materials
Bellows: The core of the metal hose is the bellows, which is made of metal sheets crimped into a series of corrugations, providing the flexibility and elasticity of the hose. Commonly used materials include stainless steel, copper, nickel-based alloys, etc. Among them, stainless steel is the most common choice because of its good corrosion resistance and mechanical strength.
reinforcing layer: The bellows are usually wrapped with one or more layers of metal braided mesh to increase the rigidity of the hose and the ability to withstand external pressure. The material of the woven mesh is usually stainless steel wire or belt.
Connector: Metal hoses are fitted with fittings at both ends for connection to other parts of the piping system. The type and size of the joint should be matched to the pipe, and the material is usually the same as the body of the hose to maintain overall corrosion resistance and strength.
Performance characteristics
Temperature resistance: Metal hoses operate in an extremely wide range of temperatures, from low to high temperatures (e.g. -196°C to 600°C).
Pressure resistance: Hoses can withstand different pressure levels from low to high, up to tens of megapascals (MPa).
Corrosion resistance: According to the corrosiveness of the medium, the appropriate metal material is selected to ensure the integrity and function of the hose for a long time.
Vibration resistance: Metal hoses are able to absorb mechanical vibrations and protect the piping system from damage caused by vibration.
Application Scenario
Refinery: It is used to connect equipment such as heating furnace, reactor, tower and pump to accommodate thermal expansion and contraction.
Chemical plant: As a flexible connection in pipelines that transport chemicals, solvents, and corrosive liquids.
Natural gas processing: In natural gas compression and processing facilities, it is used to buffer pressure fluctuations and temperature changes.
Docks and handling facilities: For loading and unloading operations of oil tankers, chemical tankers and liquefied natural gas (LNG) tankers, providing secure flexible connections.
Emergency system: As part of a quick disconnect device in fire protection systems and emergency discharge systems.
Standards and Certification
The application of metal hoses in the petrochemical industry requires adherence to strict standards and specifications such as ASME B31.3 (piping systems for chemical plants), API 650 (oil storage tanks) and EN 1459 (metal hoses for gas and oil industries). In addition, the hose may also need to be ATEX certified, indicating that it is suitable for use in potentially explosive environments.
Maintenance and Inspection
Periodic inspection: Check the appearance of the metal hoses for any signs of corrosion, cracks, or leaks.
Stress testing: Perform regular pressure tests to ensure that the hoses can withstand the specified working pressure.
Cleaning and anti-corrosion: Keep metal hoses clean and prevent corrosion if necessary, especially in corrosive environments.
In the petrochemical industry, the selection and use of metal hoses should be based on detailed technical specifications, taking into account media characteristics, operating conditions and safety requirements. Proper selection and maintenance are key to ensuring long-term reliable hosing operation.