"Engineered Surfaces for Exceptional Performance"
"Engineered Surfaces for Exceptional Performance"

Article Index

The Kermetico hand-held gun is a member of the Kermetico AK family, which means it is operated by the same control system as any of our robot-mounted guns. Kermetico have designed it for manual thermal spray and on-site coating deposition.

Existing HVOF hand-held systems are either water-cooled (which substantially limits mobility) or air cooled which provides poor coating quality due to a requirement to use a short nozzle that limits particle acceleration. Air cooling is insufficient for the use of a long nozzle in high temperature HVOF.


HVAF AK-HH High Velocity Air Fuel Portable Spray Gun

The manual AK-HH gun sprays 3 times more carbide or metal per minute than its HVOF rivals. It has better deposition efficiency than HVOF rivals with the majority of coating materials. High technological efficiency forgives distance and angle change, allowing on-site manual deposition of quality coatings.

The portable Kermetico HVAF AK-HH system is used to deposit tungsten carbide, chrome carbide, stainless steel, Hastelloy-type and Ni-based coatings onto complex surfaces of various parts and structures.

It is a heavy-duty manual coating system, made to endure harsh environments and to work long hours with high spray rates. Unlike other thermal spray processes like plasma spray, arc spray and flame spray, it deposits low oxidized, gas tight coatings with 80 MPa+ adhesion.

A Typical Cross-Sectional Micrograph of a Kermetico HVAF AK-HH Coating

A Micrograph of a NiCrBSi Coating Deposited with the Kermetico HVAF AK-HH Using 20-53 Microns Powder


Features

  • Spray rate – up to 15 kg/hour (33 lbs./hour).
  • Spray powders:
    • Tungsten carbide and chromium carbide 3-15 to 5-30 microns.
    • Metals and alloys 10-30 to 20-53 microns.
  • Dual-purpose: Manual or robot-mounted; the detachable handle is interchangeable to a robot mount fixture.
  • Net weight: 2.5 kg.
  • Axial powder injection.
  • Fuel gas options: propane, propylene, natural gas, propane-butane, MAPP.
  • Automatic ignition.
  • Blast & spray operation saves 99% of blast media, 30-50% setup and preparation time.
  • Air cooling (no need for a water chiller) makes the system portable and on-site friendly.
  • High coating quality: high density, low level of oxidation, impermeable to gas and liquids.

Options

  • Remote Pendant: The Base Station holds the gun during ignition. The gun is positioned with the handle slid over the Base Station. The Base has built-in ignition transformer and push-buttons for remote control (start, stop, cool, ignition, powder start/stop). The Base Station is cable-connected to the Controller.
  • Air inlet to the gun makes the second Handle. It has a Handle Assembly with two push buttons: stop the gun, and start/stop the powder feeder. This Assembly connects to the Base Station.

Advantages

The manual AK-HH HVAF equipment sprays powders, heated and accele­rated by the combustion products of the air-fuel gas mixture.

  • When entering the gun, the compressed air cools the gun. Then the preheated air is used for mixing with the fuel gas for combustion.
  • The mixture of pre-heated compressed air and fuel gas flows into the combustion chamber through the orifices of a catalytic ceramic insert.
  • The initial spark plug ignition of the mixture results in the heating of the insert above the mixture’s auto-ignition temperature than the hot insert then continuously ignites the mixture.
  • The spray powder is injected axially into a wide combustion chamber, where the gas flow is very slow, less than 40 m/s (130 ft./sec.)
  • The long residence time and exposure to favorable heat transfer conditions at high gas pressure, allows the powder to heat efficiently in the chamber.
  • As an optional tool for a proper heating, one may inject controlled amounts of a high heat conductivity gas (hydro­gen, helium).
  • The powder leaving the chamber is propelled into the nozzle of chosen length and configuration, where it is accelerated to a velocity that may be from 800 m/s to over 1000 m/s (2,600-3,300+ ft./sec.), dependent on the chosen nozzle and combustion chamber pressure.
  • When impacting a sub­strate, the spray powder particles form a surface coating.

Characteristics

## Specified Characteristic S.I. Units U.S. Units
1 Total heat output 80 kW 272,970 BTU/h
2 Feedstock particle size range, microns
  • Carbides
  • Metals and alloys

3-15 to 5-30

10-30 to 20-53

3 Maximum spray rate 15 kg/hour 33 lbs./hour
4 Fuel gas Propane, propylene, natural gas, propane-butane, MAPP
5 Consumption of compressed air 5,240 SLPM 185 SCFM
6 Maximum inlet air pressure 7.4 Bar 105 PSIG
7 Consumption of fuel gas, propane 65 SLPM 2.3 SCFM
8 Maximum inlet fuel pressure 7.4 Bar 105 PSI
9 Consumption of powder carrier gas, N2 Max 20 SLPM Max 0.7 SCFM
10 Gun dimensions 178 (254) x 80 x 80 mm 7(10) x 3.1 × 3.1 inch
11 Gun weight with handle 2.5kg 5.5 lbs.
12 Average thrust during gun operation 3.6 kg 7.9 lbs.

Applications

  • Refinery and chemical vessels.
  • Boiler tubes.
  • Mandrels.
  • Sleeves.
  • Complex surfaces.
  • Many more applications for HVAF spraying can be found on this direct link to Kermetico HVAF Applications Webpage.

For more information on the Manual Hand Held HVAF System, Click Here.

For more information on this equipment or consumables, call us on (07) 3823 1004, or email us using our contact form.