Uniquecoat® i7™
Internal Diameter HVAF Spray Gun
The i7 I.D. spray gun is designed for internal diameter applications, delivering high-performance cemented carbide, metal, and alloy coatings.
The i7 operates on either propylene or propane, and its highly efficient 100% air-cooling system eliminates the requirement for a chilled water supply.
The i7 internal-diameter spray gun delivers high-performance carbide, metal, and alloy coatings for internal surface applications.
● WC-based coatings with hardness up to 1550 HV300
● Variable nozzle configuration allows spraying of internal diameters as small as 120 mm
● Coating porosity typically below 0.5%
● Compressive residual stresses in deposited coatings
● Highest spray rate in class for maximum productivity
● Negligible oxide content — only 1.5–2× higher than that of the feedstock material
● Durable, dependable operation with minimal maintenance, ideal for large-scale production applications
● Axial powder injection – provides uniform particle heating and efficient material utilization
● 100% air cooling – simplifies setup and reduces system maintenance
● Continuous operation – can spray for hours without interruption
● Low operating cost – minimal fuel and air consumption with reduced maintenance requirements
● No oxygen required – safe, efficient HVAF combustion process using only air and fuel gas
● Highest spray rate in class – delivers exceptional productivity and coating throughput
● Long-life nozzles and combustion chamber – durable design minimizes downtime and replacement frequency
● Low spare part consumption – extended component lifespan reduces cost of ownership
● Fast start-up – ready to spray within seconds for maximum uptime
i7
i7 I.D. HVAF Gun
i7 Application Examples
i7 HVAF I.D. PROCESS DEMOSTRATION VIDEOS
WC-Based Coating Applied to the ID of a Rotary Airlock Valve Housing
This video demonstrates hot grit blasting followed by the application of an 86WC–10Co–4Cr coating onto the internal surface of a rotary airlock valve housing using the Uniquecoat i7 HVAF gun at a spray rate of 7.2 kg/h. The substrate material is cast iron, and the resulting coating thickness is approximately 150 µm.
Support Ring Preparation and HVAF Coating Application
This video demonstrates the internal surface preparation of a separating screen support ring using hot grit blasting with the Uniquecoat i7 HVAF gun, followed by the application of an 86WC–10Co–4Cr coating using the same gun. The substrate material is stainless steel, and the resulting 250 µm-thick coating provides greatly extended service life of the support ring in abrasive operating conditions.
Hot Grit Blasting of a Separating Screen ID
This video demonstrates the internal surface preparation of a separating screen using hot grit blasting with the Uniquecoat i7 HVAF gun. The substrate is thin stainless steel, and the hot grit blasting process virtually eliminates substrate warping compared to conventional grit blasting. It also significantly increases coating bond strength while reducing both operating time and grit consumption.
Application of 86WC-10Co-4Cr Coating to a Separating Screen ID
This video demonstrates the application of an 86WC–10Co–4Cr coating onto the inner diameter of a separating screen following hot grit blasting, using the Uniquecoat i7 HVAF gun. The coating thickness is approximately 125 µm, applied at a spray rate of 8 kg/h.
Internal CrC-Based Coating of a 120 mm Tube
This video shows hot grit blasting and the application of a 0.3 mm CrC-25NiCr coating onto a 120 mm-diameter tube using the Uniquecoat i7 HVAF gun. A 120 mm ID is the minimum size coatable with the i7; for smaller diameters down to 65 mm, the i5 gun is recommended.
The i7™ Powder Stream at 120 g/min Feed Rate
The video demonstrates the stable discharge of Amperit 558.059 powder from the Uniquecoat i7 HVAF gun nozzle at a feed rate of 120 g/min.
i7 Coating Microstructure
TYPICAL i7 COATING CROSS-SECTION MICROGRAPHS
