Performance breakthrough of high-temperature HDPE fittings
Traditional high-density polyethylene (HDPE) materials will show obvious strength loss and creep phenomenon when the temperature exceeds 60°C, but specially modified HDPE fittings for high-temperature applications have successfully broken through this limitation:
1. Extended temperature range: The new high-temperature HDPE fittings can be used for a long time in the temperature range of -40°C to 95°C, and the short-term tolerance temperature can reach 110°C.
2. High-temperature strength retention rate: It can still maintain more than 60% of the normal temperature strength at 90°C, which is much better than ordinary HDPE materials.
3. Creep resistance: The special molecular structure design reduces the creep rate of the material at high temperature by more than 70%.
4. Long-term thermal stability: Adding an efficient heat stabilizer system ensures that the service life in a high-temperature environment can still reach more than 30 years.
5. Enhanced chemical resistance: The resistance to various chemical media under high temperature conditions is significantly improved.
Key modification technologies for HDPE fittings for high-temperature applications
1. Molecular structure optimization:
Using bimodal polyethylene technology
Introducing long-chain branched structure
Optimizing molecular weight distribution
2. Nanocomposite technology:
Layered silicate nanocomposite
Carbon nanotube reinforcement system
Nano zinc oxide heat stabilizer
3. Cross-linking modification technology:
Electron beam radiation cross-linking
Silane cross-linking
Peroxide cross-linking
4. Blending modification technology:
Blending with engineering plastics such as PP and PA
Liquid crystal polymer reinforcement system
Elastomer toughening modification
5. Additive system optimization:
Compound antioxidant system
High-efficiency UV stabilizer
Metal passivator
Main types of high-temperature HDPE accessories
1. Connecting accessories:
High-temperature socket pipe fittings
Flange connectors
Threaded joints
Slip-on flanges
2. Steering accessories:
High-temperature elbows (45°/90°)
Tee/cross pipe fittings
Y-type flow dividers
3. Variable diameter accessories:
Concentric/eccentric reducers
Reinforced reducer at pipe end
4. Sealing accessories:
High-temperature sealing rings
Expansion joints
Manhole covers
5. Special accessories:
High-temperature valve components
Thermal compensators
Sensor interface parts
Application areas
1. Industrial hot water system:
Boiler room circulating water network
Process hot water delivery system
Heat recovery device connection
2. Geothermal utilization project:
Ground source heat pump underground loop
Hot spring delivery network
Geothermal heating system
3. Solar thermal utilization:
Solar collector connection system
Hot water tank connection pipeline
Overheating safety loop
4. Chemical process system:
Low-temperature heat medium delivery
Chemical intermediate pipeline
Waste heat recovery device
5. Food processing industry:
CIP cleaning system
Pasteurization pipeline
Hot filling production line
6. Regional heating network:
Secondary network system
Heat station connection pipeline
Indoor heating system
Special design requirements for HDPE fittings for high-temperature applications
1. Pressure derating design:
For every 10°C increase in working temperature, the design pressure needs to be reduced by 10-15%
At 90°C, the design pressure is generally 50% of the rated value at normal temperature
2. Thermal expansion compensation:
The linear expansion coefficient is about 0.2mm/m·°C
Expansion rings, Ω-type compensators or flexible connections are required
3. Support spacing optimization:
The support spacing needs to be shortened by 30-40% under high temperature conditions
Avoid excessive deflection and stress concentration
4. Connection seal reinforcement:
Double sealing structure
Special high-temperature sealing materials
Enhanced electric fusion connection parameters
5. Protective layer design:
UV-resistant outer layer
Insulation layer
Oxygen barrier layer
Installation points of HDPE fittings for high-temperature applications
1. Pretreatment requirements:
Put in working environment temperature 24 hours before installation
Special cleaning treatment of connection end surface
Strictly check the status of seals
2. Hot melt connection process:
Temperature control is 10-15°C higher than normal
Extend heat absorption and cooling time
Adopt step-type pressure control
3. Mechanical connection notes:
Use special high-temperature gaskets
Bolt torque is applied in stages
Reserve thermal expansion gap
4. System pressure test specifications:
Perform final test at operating temperature
Extend pressure holding time by 50%
Adopt temperature-pressure combined test method
5. Operation and maintenance suggestions:
The first temperature rise needs to be carried out in steps
Regularly check the status of the support system
Monitor thermal deformation
The development of HDPE fittings for high-temperature applications has successfully broken through the temperature limit of traditional polyethylene materials and provided a new solution of lightweight, corrosion-resistant and long life for high-temperature fluid delivery systems.
