New with a filtration question
Posted: Thu Dec 10, 2020 10:57 am
Hello, I’m Eric
I typically only read these forums, and rarely can’t find an answer deep in a thread, but this time I’m stumped so here I am to ask my question.
I’ll include the question here as well as in the general welding.
I know a lot of people weld SST with just a N100 half mask, and some even use PAPR’s... I personally use a Versaflow PAPR all day at work due to the process environment I’m in manufacturing AM powder. The Versaflow only has HEPA filters available. So when it came to buying a new Speedglas hood to use with my Versaflow, I ended up going with the ADFLO PAPR as you can add a OV/gas filter cart after the particulate filter.
I’m a contractor, so I buy what I want... however my clients guys that I’m welding with are at the mercy of their employer to get them their PPE. And a PAPR w/HEPA filter far exceeds what OSHA calls for (from my understanding). So these guys can’t get the new ADFLO PAPR’s for a couple hundred more.
My observation that leads to my question:
HEPA filtration starts at around .3 micron
Hex chrome fume is distributed in particle sizes from .05 - 2.0 micron
I read somewhere that 80% of the particle distribution is in the smaller size range... closer to the .05 micron size
If this is true, most of the hex chrome fume could pass through a HEPA filter.
My evidence of this... put on a PAPR with only a HEPA particulate filter and fart. You didn’t smell 100% of that fart, nothing above .3 micron at least, but you smelled way too much of it.
My question:
What do you guys that weld SST all day use?
I typically only read these forums, and rarely can’t find an answer deep in a thread, but this time I’m stumped so here I am to ask my question.
I’ll include the question here as well as in the general welding.
I know a lot of people weld SST with just a N100 half mask, and some even use PAPR’s... I personally use a Versaflow PAPR all day at work due to the process environment I’m in manufacturing AM powder. The Versaflow only has HEPA filters available. So when it came to buying a new Speedglas hood to use with my Versaflow, I ended up going with the ADFLO PAPR as you can add a OV/gas filter cart after the particulate filter.
I’m a contractor, so I buy what I want... however my clients guys that I’m welding with are at the mercy of their employer to get them their PPE. And a PAPR w/HEPA filter far exceeds what OSHA calls for (from my understanding). So these guys can’t get the new ADFLO PAPR’s for a couple hundred more.
My observation that leads to my question:
HEPA filtration starts at around .3 micron
Hex chrome fume is distributed in particle sizes from .05 - 2.0 micron
I read somewhere that 80% of the particle distribution is in the smaller size range... closer to the .05 micron size
If this is true, most of the hex chrome fume could pass through a HEPA filter.
My evidence of this... put on a PAPR with only a HEPA particulate filter and fart. You didn’t smell 100% of that fart, nothing above .3 micron at least, but you smelled way too much of it.
My question:
What do you guys that weld SST all day use?