Direct and Indirect Heaters – API 560, API 12 K and othersGas Treatment back to Products NOVARGI owns the in-house capability to design all types of process heaters. Fired heaters can be produced in the following types in accordance with Client needs: Cylindrical Fired Heaters Cabin Type Fired Heater Air Preheating Systems Helical Coil Heaters Indirect Bath Heaters Others