Expanding & Shrinking

Pipe expansion principle and types

The working principle of a pipe expander is usually to use mechanical pressure or hydraulic pressure to insert a conical mandrel or a multi-lobed expander head into the inside of the pipe and squeeze the pipe wall outward to make its diameter expand uniformly. 

The main types include:

• Manual expander:
  • FeaturesSmall in size and lightweight, it is usually equipped with a ratchet mechanism to save physical effort. Suitable for small-scale applications such as on-site repair and air conditioning installation.
  • applicationAir conditioning copper pipe installation and plumbing/electrical repair.
• Electric/Lithium-ion Battery Expander:
  • FeaturesDriven by batteries or power, it automatically completes tube expansion, saving time and effort and achieving high efficiency.
  • applicationProfessional air conditioning installation, batch on-site operations.
• Hydraulic Expanding Machine:
  • FeaturesThe hydraulic system provides a powerful and stable expansion force, suitable for large-diameter, thick-walled pipes, and even for the manufacture of boiler-related heat exchangers.
  • applicationHeavy industry, boiler manufacturing, and production of large heat exchangers.
• Automatic Double-end Expander:
  • FeaturesIndustrial-grade machines can simultaneously perform forming processes such as flaring, shrinking, flanging, punching, or sealing on both ends of pipes. They typically employ servo control to ensure high precision.
  • applicationSatellite ear brackets, automotive parts, and automated production lines for mass production of tubing. 

Application areas

Pipe expanders are widely used in various industries that require pipe connections:

• Air conditioning and refrigerationThe copper pipe is flared to facilitate the connection of refrigerant lines and reduce the number of welding points.
• Heat exchangers and boilersExpand the heat exchange tubes to the tube sheet to ensure a tight seal.
• Automobile manufacturingEnd forming of exhaust pipes and oil line fittings.
• Furniture manufacturing: Connection and assembly of metal furniture fittings.
• Building and HydropowerConnection of PVC water pipes and metal water pipes.

The following are the various types of tube expanders:

Market Trends in 2026

With the increasing demand for automated production, the market trend for pipe expanders in 2026 emphasizes high efficiency and multi-functional integration. Many devices can not only expand pipes but also shrink them simultaneously, achieving integrated "expansion (shrinkage)" operations. In addition, hand-operated and electric pipe expanders are becoming increasingly popular, improving the convenience of on-site construction.