This document discusses pulse jet technology as a viable green alternative for stripping HVOF coatings. It provides several benefits over traditional stripping methods such as no chemical baths, less energy usage, solid waste disposal, water recirculation, and no substrate damage. The document outlines the technical merits and environmental benefits of pulse jet stripping. It also provides examples of its applications in stripping HVOF coatings from aircraft parts and print press rolls.

1. “PULSE JET” A VIABLE GREEN
ALTERNATIVE TECHNOLOGY
FOR STRIPPING HVOF COATINGS
VLN Advanced Technologies
Ottawa, Ontario, Canada
Advanced Technologies Inc. www.vln-tech.com

2. MERITS
ENVIRONMENT-AL
COST SAVINGS TECHNICAL
BENEFITS
SMALL FOOTPRINT NO HYDROGEN NO CHEMICAL BATHS
EMBRITTLEMENT NO HexCr ISSUES
LINE-OF-SIGHT TECH
SELECTIVE SPOT REPAIRS USES LESS ENERGY
LOW CAPITAL COST
NO SUBSTRATE DAMAGE SOLID WASTE DISPOSAL
LOW OPERATING COST
DIMENSIONAL STABILITY USES WATER ONLY
HIGH T.A.T
REPRODUCIBILITY WATER RECIRCULATION
USES LESS ENERGY
Advanced Technologies Inc. www.vln-tech.com

3. HIGH-FREQUENCY FORCED PULSE WATER JET
Regular Waterjet (CWJ)
Forced Pulsed Waterjet (FPWJ)
Advanced Technologies Inc. www.vln-tech.com

4. PULSE JET PHENOMENON
EFFECTS:
O lse
Pu
N
- Dynamic Water Hammer
- Cyclic Loading at 20 kHz
- Aggressive Cavitation
- Widening of Jet Diameter lse
Pu FF
O
Advanced Technologies Inc. www.vln-tech.com

5. DESIGN MECHANISM
CHALLENGES:
- Performance
- Kinematics
- Size and Weight
- Machining Tooling
- Repeatability
Advanced Technologies Inc. www.vln-tech.com

6. MESSIER-DOWTY LANDING GEAR PIN WORK
- WC-Co-Cr 0.017”
Thick HVOF Coating.
- Removed with 15,000
psi. On Gantry System
- Undamaged Finish and
Repeatability.
- Flash Rust Inhibitor
Can be Used

7. SECTIONAL PROFILE INSPECTION
200X Magnifications
- WC-Co (HVOF)
180um (7 mils) thick.
- Deep stripping.
- De-lamination of
HVOF coating.
-Original profile
undamaged.
Advanced Technologies Inc. www.vln-tech.com

8. AIR FRAME with HVOF COATING SYSTEM
Ultra High Pressure 40Kpsi
- Power = 156 HP
- Removal Rate = 0
PULSE JET 10Kpsi
- Power = 46 HP
- Removal Rate = 4 ft2/hr
Advanced Technologies Inc. www.vln-tech.com

9. Insitu HVOF Coating Removal
(PRINT PRESS ROLLS)
- Single jet application
- Part turning, gun
stationary
- Pedestal robot
mounted
-Roll coating 316 S.S
¼ thk.
- 5 times faster than
machining.

10. CONCLUSIONS
- Pulse Jet can remove various Plasma and HVOF Coating
effectively using only water and without damage to
substrate.
- Pulse jet works best with automation techniques.
- Net removal rate range 2-150 ft2/hr depending on coating
conditions.
- Environmentally friendly technique.
- Adaptive with plasma spray technology.
Advanced Technologies Inc. www.vln-tech.com

11. Thank You AIAC!
For Further Information
Visit Our Website:
www.VLN-TECH.COM
Advanced Technologies Inc. www.vln-tech.com