Product Introduction
Sleeve-type pipe expansion joints are the core components used to compensate for thermal expansion and contraction in pipeline systems. Their design combines high-strength materials and innovative structures, which are suitable for long-term stable operation under complex working conditions. The following is a structured product introduction that integrates multi-source information:
I. Structural principle and core components
Infrastructure
It is composed of core tube (sliding sleeve), outer sleeve, sealing system (flexible graphite ring/PTFE packing) and anti-pull-breaking device. Through the axial slip of the inner and outer sleeves, the deformation of the pipeline is absorbed, and the compensation amount can reach twice that of the ordinary compensator.
Sealing technology
Using flexible graphite ring or composite sealing material, the friction coefficient is as low as 0.04~0.10, it has both oxidation resistance and self-lubrication, and can withstand the high temperature medium of 600℃. In case of seal failure, performance can be restored by fastening flanges or superimposing sealing rings, eliminating the need for overall replacement.
2. Technical parameters and performance advantages
| Category | Parameters/Characteristics |
|---|
| Pressure range | ≤2.5MPa (high-pressure type can be customized to higher grade) |
| Temperature range | -40℃ ~600℃, special coating model can withstand instantaneous high temperature of 350℃ |
| Corrosion resistance | Special surface treatment, chloride ion corrosion resistance is more than 50 times that of austenitic stainless steel, suitable for seawater, chemical media |
| lifetime | The fatigue life is the same period as the pipeline, and the design life is> 30 years |
Product Types and Applicable Scenarios
Functional Classification
Unidirectional type: Directional compensation for axial displacement, suitable for straight pipeline;
bidirectional typeThe sleeves at both ends slide freely, and the bidirectional compensation amount is increased by more than 30%, which is suitable for complex pipelines with changeable medium flow direction;
Direct burial type: There is no need to set up maintenance wells, directly buried and installed, reducing the comprehensive cost by 20% ~40%.
Industry Application
Thermal pipe networkAbsorb the thermal displacement of the steam pipeline and be used with a three-eccentric seal butterfly valve;
Petrochemical industryCompensation for deformation of corrosive medium pipeline containing chloride ion and salt solution;
Municipal Engineering: The direct buried design is suitable for underground water supply, drainage and heating pipe network.
4. Comparing the advantages of traditional expansion joints
Pressure resistance: Compared with bellows expansion joint, the pressure bearing capacity of sleeve type is increased by more than 3 times, which is more suitable for high-pressure system;
Maintenance costs: There is no need for overall replacement, and local maintenance can save 60% maintenance cost;
Spatial adaptability: Compact structure saves installation space, especially suitable for dense pipe gallery areas.
V. Key points of type selection and installation
Selection basis: Media parameters (temperature, pressure, corrosiveness), compensation amount, connection mode (flange/welding) and installation environment (overhead/direct burial) are required;
Installation Specifications: The direction of the liner cylinder should be consistent with the flow direction of the medium, and the cold tightening pre-deformation should be operated under professional guidance. It is prohibited to forcibly twist the compensator.
Through multi-dimensional performance optimization, sleeve-type pipe expansion joint has become the preferred compensation scheme in high temperature, high pressure and corrosive environment. For relevant technical standards, please refer to GB/T 12777-2019 General Technical Conditions for Expansion Joints of Metal Bellows.
