Emerging US DOE Engineer here...

[mark.fein]

Hey,

First, I am very impressed by the breadth of knowledge that has been put together here over the past decade; who knew so many people cared about flame-spraying! Now onto my question.

My research group bought a TAFA (Praxair) Thermal Spray HVOF system a few years back (c. 2015) and I recently joined (January 2018) the group after the last tech/engineer quit. They had been struggling for a while and brought me on to solve some of the issues their current setup was facing:

- JP 8200 with HVOF: foul starts and interrupted runs from various low fuel pressure/low oxygen alarms.

- 1264WL Powder Feeder: Clogging of salt-based powder (potassium carbonate) used for plasma generation, incorporation of independent scale measurement.

So i more or less took my experience as a test method validation engineer and did some RCA on these issues and the system has been running well for the last 6 months. Only recently have we began to get some of these errors that apparently only the "certified TAFA tech" can fix (for a hefty fee, of course):

- Low Fuel Pressure alarms when moving from "ramp-down" mode to "ramp-up" mode.
- Low carrier gas/ out of tolerance alarms (shuts down torch) when going from 2-3 LPM of carrier gas to 5+ LPM. Doesn't happen if you start high (~15 LPM) and go down.

Any useful advice on maintaining these systems or, even better, any actual drawings of the internals of the JP 8200?

I am trying to learn this system in and out and have pretty much hit a roadblock with the manufacturer, so I turn to you all.

From Oregon w/ love,

M. F.