Hairpin or double pipes heat exchangers are characterized by a construction form which imparts a U-shaped appearance to the heat exchanger. These heat exchangers consist of two shell assemblies housing a common set of tubes and interconnected by a return-bend cover referred to as the bonnet.
- Lower surface due to counter current flow suitable for services having a temperature cross.
- Typically expansion joint are not required due to U-tube construction.
- Longitudinal finned tubes can be used resulting in a compact heat exchanger for shell side fluids having a low heat transfer coefficient.
- Shorter delivery compare to the other exchanger types.
- Additional sections can be added at a later time due to modular design.
- Easy to clean, inspect, and tube element replacement.
- Multiple hairpin sections are not always economically competitive with a single shell and tube heat exchanger.
- Proprietary closure design requires special gaskets.