You are here:

OMP and HTH series
Multitubolar oil heaters

Patented multitubular structure composed of a parallelepiped-shaped combustion chamber fully screened by tangent tubes (total absence of refractories) overlying on a convective section.
A wide range of thermal capacities and the optimization on market requests make these heaters ideal for applications which requires medium-big thermal capacity.   

Key features


Thermal capacity

1.7 – 40 MW



up to 400°C



up to 93%


NOx emissions

80 mg/Nm³
(lower values on request)


H2 ready2OK

Compact modular design: these boilers are delivered as a fully equipped and ready-to-connect boiler, minimizing on-site installation work.

Ease of maintenance: inspection hatches provide easy access for inspection, cleaning, and service operations. In boilers operating on heavy fuels, automatic soot blowers are provided to clean the furnace from combustion products.

Design and manufacturing realized according to the most important international standards CE-PED, ASME, RTN, SELO.

Low NOx emissions less than 80 mg/m3 due to an optimized combination with any market burner (according to BAT).

Combustion system suitable for different fuels.

Multitubular boilers are designed and built according to the customers‘ requirements and can be adapted to work with high heating medium temperatures or for applications where higher than standard power is required.

High thermal efficiency – up to 93% – due to the use of a countercurrent heat exchange scheme in the convective section and the presence of a built-in air combustion preheater in front of the burner.

Intelligent system for monitoring operating parameters and boiler control with the ability to integrate into a single complex with automation of technological lines.

Long service life due to a balanced design with smooth heating of the fluid during cold starts and protection against thermal shocks in the radiator pipes.

Conceived for heavy-duty applications, HTH are thermal fluid horizontal type heaters with a multitubular design built for capacities ranging up to 40 MW. They can operate on the synthetic thermal fluid in both liquid and gaseous phases with temperatures up to 400°C.

These boilers find application in those industries where high processes temperatures are requested, such as the production of polyester, PET, nylon, paints, resins.

OMP series

The internal structure of these boilers is a multitubular design with a large combustion chamber. Bundles of pipes bent at an angle of 90° pass through holes in two walls of the portal-shaped collector. Pipe connections are made by arc welding by qualified welders. The convective pipes and the combustion chamber are placed in a thermally insulated stainless steel case, the burner is connected to the boiler, and the fittings and measuring instruments necessary for operation are installed.

In addition, the heater is supplied packaged, with the air preheater integrated on the front side.

Due to the convective tube bundle and large combustion chamber, OMP, and HTH heaters provide large heating surfaces with a small footprint.

The geometry of the combustion chamber allows a large space for flame development and results in low thermal loads. As a consequence, very low NOx emission levels can be achieved, even with combustion air preheating.

Heaters of these series have a large heating surface, due to the geometry of the convective tube bundle, working in counter-flow and the large radiant section, completely screened by tubes.

Inspection doors around the heater ensure easy access to the pressure parts, to reduce downtime for maintenance or repair operations. The absence of a refractory wall at the back reduces extraordinary maintenance events drastically, making these heaters particularly suitable for the combustion of heavy fuel oil, which requires frequent cleaning of internal parts and can damage refractory walls.

The thermal oil enters the convective section, at a lower temperature and only later goes into the hotter radiant section, reducing thermal shocks on the oil, especially during start-up. The absence of refractory walls on the back does not allow unwanted heat transfers from refractory to oil when the plant shuts down. Such transfers with no circulation could cause cracking of the thermal oil.

After assembly, each boiler is subjected to a series of industrial tests that simulate the operating conditions of the customer.

Compatible products


Our constant commitment to improve combustion efficiency and reduce pollutants released into the atmosphere has led us to develop high-performance burners that are able to:

  • Reduce NOx and CO2 emissions to handle Flue Gas Recirculating systems
  • Burn standard and special fuels (natural gas, hydrogen, biogas)
  • Ensure high flame stability
  • Guarantee wide turndown ratios

Our burners are designed and manufactured to perfectly combine with our own boilers’ combustion chamber geometry, optimizing thermal load regulation management.

Skid pump

Composed of two elements, an oil circulation pump and a control system installed inside the electrical panel, it is necessary to circulate the oil inside the boiler and the entire plant. Fluid circulation pumps must be correctly sized in flow rate and prevalence to ensure correct fluid velocity in the circuit.

Expansion tank

This tank is conceived for absorbing the volumetric expansion of the diathermic fluid in the circuit due to thermal expansion caused by oil heating. Using a tank with the function of a well-dimensioned expansion vessel allows not to put the circuit under pressure beyond the design values.

Thermal oil drain tank

A storage tank where the oil is stored when the system is emptied for maintenance or other activities.


An indirect steam generator that makes it possible to exploit the heat coming from a thermal oil heater to produce energy in form of steam. Inside, the hot oil passes through a coil that heats the water and transforms it into steam.

OMP series

Technical data

OMP 2000OMP 2500OMP 3000OMP 4000OMP 5000OMP 6000OMP 8000OMP 10000OMP 12500

Thermal capacity
Thermal efficiency [%]Up to 93%Up to 93%Up to 93%Up to 93%Up to 93%Up to 93%Up to 93%Up to 93%Up to 93%
Thermal oil flow rate [m3/h]105180180205250300400450480
Length [mm]
(with burner)
Width [mm]
(with accessories)
Height [mm]2.9003.2003.2003.2703.8303.8804.0004.0505.500
Oil content [Lt]9501.4001.4001.4502.3412.6503.4704.5105.300