Flanged Circulation Heaters

Circulation heaters are highly efficient heating cells designed to heat liquids and gases as they flow through a pipe body. These units are compact, and easy to install. They offer primary heating or act as a backup/start up heating source to natural or forced circulation systems.

The core of a Bucan circulation heater is a screw plug immersion heater or a flanged immersion heater that is installed into a pipe vessel. The vessel is thermally insulated and a stainless steel or rust proof painted outside metallic jacket protects the insulating material. The vessel is connected to a system through inlet and outlet NPT threaded fittings or flange connections.

Circulation heater design concept incorporates all the rugged and durable features of a tubular heater with the flexibility of a heat exchanger.

Design specifications may require a unit to meet the boiler and pressure vessel code. Bucan can supply units that are designed, built and registered to the ASME code, with the applicable code stamps.


Nominal vessel size A C D E F G Inlet/outlet size (NPT)
3" Heated section of the heater 5.5 7.5


9.5 5.5 1"
4" 5.5 9.0 10.5 6.25 1 1/2"
5" 6.75 10.0 11 7 1 1/2"
6" 6.75 11.0 12 7 1 1/12"
8" 6.75 13.25 13.5 8.5 2"
  • Sheath materials - selected to suit the liquid or gas being heated
  • Connections - NPT nipples or flanged inlet and outlet connections
  • Flange pressure ratings -  selected based on the temperature and pressure design conditions
  • Terminal Enclosures
    • General Purpose (NEMA 1)
    • Weather Resistant (NEMA 4)
    • Hazardous Location (NEMA 7)
  • Passivation - when required
  • Support frames - for stand-alone mounting
  • Vessel materials - steel, stainless steel, or other specialty metals
  • Cross flow baffles - to improve heat transfer characteristics, when required
  • Controls - built in thermostats, thermocouples, and high limit thermocouples