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

Article Index

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 

Gun

AK07

C-7

AK-06

C-6

AK5

AK5-ID

AK4-ID

Nozzle

5L

5L

5E

5E

100L

60L

2

Chamber Pressure PSI

64

73

75

73

78

79

78

Air to Gun Setting PSI

91

84

90

80

91

91

90

Differential Pressure PSI

27

11

15

7

13

12

12

Air Flow SCFM

Total Work

300

282

235

187

185

125

61

Total Gun Startup

360

382

300

270

240

185

85

Combustion Air Work

 

112

 

77

 

 

 

Combustion Air Startup

 

212

 

160

 

 

 

Cooling Air

 

170

 

110

 

 

 



Compressor Minimal Requirements

1. Single Compressor Setup

Min. Pressure to Controller PSI

108

100

108

100

105

105

110

Nominal Pressure PSI

125

115

125

115

120

120

125

Min. Flow SCFM

378

400

315

284

264

204

94

Compressor HP

95

100

79

71

66

51

24

 

2. Two Compressor Setup

C-7

C-6

 

 

a) Combustion Air Compressor

Minimum PSI

 

100

100

 

 

Nominal PSI

 

115

115

 

 

Min. Flow SCFM

 

223

168

 

 

Estimated HP Min.

 

56

42

 

 

b) Cooling Air Compressor

Min. PSI

 

105

105

 

 

Nominal PSI

 

115

115

 

 

Min. Flow SCFM

 

179

116

 

 

Estimated HP Min.

 

45

29

 

 


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.