Set Up Requirements for HVAF

Compressed Air

Clean and dry air should be used for HVAF & HVOF operation.

Definition of “Clean”: Particulates of at least 10 micron size have to be removed from the supply air line. This is achieved by using the oil filter and particulate filter. For combustion air line, it is recommended to install the filters AFTER the receiver (air tank) to minimize air pressure drop in the receiver during the gun ignition (when high volume of air is used, resulting in fast pressure drop in the receiver).

Definition of “Dry”: it is rather a requirement for consistent moisture content in the air, than a requirement for a specific content of moisture (dew point). In fact, combustion is better initiated and sustained when moisture is present in the air due to high thermal conductivity of water. Herewith, heating of spray particles also depends on the gas heat conductivity – i.e., depends on the moisture content in the air. Thus, for consistent coating deposition and quality results, it is recommended that the moisture content in the air is consistent. The latter is usually achieved by installing a refrigerated air dryer in the line after the filters (unless the dryer is already integrated in the air compressor).

Single Designated Air Compressor Setup

• Designated rotary screw compressor: 400 CFM @ 125 PSI (approx. 100 HP) or larger is recommended to run all currently available guns. Minimal single air compressor requirements for each gun are listed in the Table 1. Maximum inlet air pressure into the console is 150 PSI.
• Dry and clean air (oil filter, particulate filter and refrigerating air dryer are recommended; all connections – 2” NPT).
• Recommended air pipe size: 2-inch pipe with 2”NPT connections minimal.
• Valve: shutoff valve must be installed.
• Connector after valve: Female 1-1/4” NPT (Kermetico supplies 5-feet 1-1/4” hose with Male 1-1/4” NPT nipple to connect to the control console).

Two Compressors Setup

• Designated air compressor for combustion line and separate air compressor for cooling line (only C-7 and C-6 guns).

Combustion line: designated rotary screw air compressor:

• C-7 Gun: 225 CFM @125 PSI (approx. 56 HP) or larger.
• C-6 Gun: 180 CFM @125 PSI (approx. 45 HP) or larger.
• Dry and clean air (oil filter, particulate filter and refrigerating air dryer are recommended; all connections – from 1” NPT to 1-1/4” NPT).
• Recommended air pipe size: 1-inch pipe with 1”NPT connections minimal.
• Valve: shutoff valve must be installed.
• Connector after valve: Female 1-1/4” NPT (Kermetico supplies 5-feet 1-1/4” hose with Male 1-1/4” NPT nipple to connect to the control console).
• Minimal compressor requirements are listed in the Table. Maximum inlet air pressure into the console is 150 PSI.
• The combustion air line in the console is oversized to 1-1/4” to allow running of AK7/AK6 HVAF guns, which have a single air supply for combustion and cooling.

Cooling line: Shop or designated compressor:

• C-7 Gun: 180 CFM @ 105 PSI (approx. 45 HP) or larger.
• C-6 Gun: 120 CFM @ 105 PSI (approx. 30 HP) or larger.

Clean air (oil filter, particulate filter for at least 25-micron particles removal are recommended; all connections – 1” NPT).

• Recommended Air Pipe Size: 1-inch pipe with 1” NPT connections minimal.
• Valve: Shutoff valve must be installed.
• Connector After Valve: Female 1” NPT (Kermetico supplies 5-feet 1”-hose with Male 1” NPT adapter to connect to the control console).
• Minimal compressor requirements are listed in the table below. Maximum inlet air pressure into the console is 150 PSI.

Minimal Requirements for Air Compressor for Different Spray Guns 

NOTE: When using carbon steel piping for air supply, it is highly recommended to set additional particulate air filter at the control console to capture fine rust forming in the piping.