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Thermal Spray Coating / HVOF / HVAF Coating

Arudra Engineers is an ISO certified company providing Anti corrosive Protective coating application to overcome Corrosion and Erosion problems in many industries.


Thermal spraying is a group of coating processes in which finely divided metallic or nonmetallic materials are deposited in a molten or semi-molten condition to form a coating. The coating material may be in the form of powder, wire or molten materials.

Arudra has done Thermal Spray Coating job for various projects / life plant that includes KNPC Kuwait, ONGC and HPCL and SPIC, India etc., as per Shell DEP specification and ONCGOffshore Design Specification No: 2005 and other local TSC specification / standard as per customer requirements.


  • We serve various Industries like Oil and gas, Power plant, Marine Industries, Paper & Steel plant, Chemical, Fertilizer, Autombiles and other General Industries+ etc.,
  • Arudra has all the required resources, good financial strength and quick mobility facilities to carry out the job.
  • Arudra will do Twin Wire Arc Spray / Flame Spray / HVOF / HVAF as per customer requirements
  • Arudra has SSPC / NACE certificed, Experienced Applicator and Level II Quality Control Inspectors
  • Arudra will follow highest standard on HSE norms.


High Velocity Air Fuel Thermal Spray Process

The HVAF (High Velocity Air Fuel) Thermal Spray Process is basically the same as the HVOF (High Velocity Oxygen Fuel) process except that this process uses air instead of oxygen.

The coatings produced by HVAF are similar to those produce by the HVOF process. HVAF coatings are very dense, strong and show low residual tensile stress or in some cases compressive stress, which enable very much thicker coatings to be applied than previously possible with the other processes.

Most HVAF systems are air cooled using the same air for combustion.

While air is free compared to oxygen, this is slightly offset by the cost of larger air compressors required.

The very high kinetic energy of particles striking the substrate surface do not require the particles to be fully molten to form high quality HVAF coatings. This is certainly an advantage for the carbide cermet type coatings and lower melting point materials and is where this process really excels.

HVAF coatings are used in applications requiring the highest density and strength not found in most other thermal spray processes. New applications, previously not suitable for thermal spray coatings are becoming viable.

HVOF -High Velocity Oxygen Fuel Thermal Spray Process

The HVOF (High Velocity Oxygen Fuel) Thermal Spray Process is basically the same as the combustion powder spray process (LVOF) except that this process has been developed to produce extremely high spray velocity. There are a number of HVOF guns which use different methods to achieve high velocity spraying. One method is basically a high pressure water cooled HVOF combustion chamber and long nozzle. Fuel (kerosene, acetylene, propylene and hydrogen) and oxygen are fed into the chamber, combustion produces a hot high pressure flame which is forced down a nozzle increasing its velocity. Powder may be fed axially into the HVOF combustion chamber under high pressure or fed through the side of laval type nozzle where the pressure is lower. Another method uses a simpler system of a high pressure combustion nozzle and air cap. Fuel gas (propane, propylene or hydrogen) and oxygen are supplied at high pressure, combustion occurs outside the nozzle but within an air cap supplied with compressed air. The compressed air pinches and accelerates the flame and acts as a coolant for the HVOF gun. Powder is fed at high pressure axially from the centre of the nozzle.


Coating Material

Metal Alloy Powder
Stainless Steel
Bronze | Inconel | Hastalloy Tungsten Carbide
Chrome Carbide
Nickel Chrome Carbide
Nickel Carbide

Coating Process

  • Flame Spray

  • Twin wire Arc Spray

  • High Velocity Oxygen Fuel (HVOF)

  • High Velocity Air Fuel (HVAF)

Application Industries:

  • Oil, Gas & Petrochemical industries

  • Power plant.

  • Mining industries

  • Marine industries

  • Paper & Process plant

A basic thermal spray system consists of the following:

  • Spray gun: The core device performing the melting and acceleration of the particles to be deposited
  • Feeder: For supplying the powder, wire or liquid to the torch
  • Media supply: Gases or liquids for the generation of the flame or plasma jet, gases for carrying the powder, etc.
  • Power supply: often standalone for the torch
  • Control console: either integrated or individual for all of the above

The Jobs will be carried out by certified Thermal Spray Coating Applicators, as per customer specifications.

We have all the required inspection equipments to validate the Thermal Spray Process by certified QC inspectors.