Air fed Mask info?

[busastars]

This could have been posted in H&S or Compressor section but think Paint section is more relevant.

Trying to research more on Air Fed Masks so could do with a few experts here to help me understand them.

Now from all I can find out is they require about 7cfm, to me this seems like a huge amount of Air for just a mask not doing anything apart from giving a clean supply of Air to breath.

How come they use or need so high cfm?

My understanding is most house power supplies 3pin will run upto 3hp motors, I have a 3hp 100L compressor think its just over 14cfm. I cannot see why this wont run a small HVLP gun and an Air Fed Mask but have read 3hp is not enough for spraying and Air Mask.

Can someone please help me understand why or why not, would it make any difference if it was for very short periods of use at any time?

Cheers

 

[Chipper]

Your 14cfm will be displacement, not FAD (delivered) air. Thats probably in the 9cfm range of which a mask probs wants 6-7.

HVLP usually means a lot of air required, my mini one wanted 9cfm on it's own. But my conventional mini only wants 2-4cfm (mind, it's flogged by some places as "HVLP", but it ain't that..)

 

[rtbcomp]

Certainly with blasting helmets as well as supplying breathing air they need a high airflow otherwise the turbulence outside the mask could force contaminated air back into it; I guess the same could apply to spraying masks.

The cfm quoted could be at the relative low pressure inside the mask and not at the output pressure of the compressor.

 

[busastars]

I'm trying to find out my FAD with not much luck but would be nice to know, it is a 14cfm Clarke Airmaster turbo tiger 15/55 3hp.

Thing is some house supplies will just about cope with 3hp motors so I would guess adding another 2hp compressor to run a mask would trip the house out, how do most people manage at home.

Not sure if it makes any difference but it would be short use, the compressor only goes off after every 2nd or 3rd coat.

 

[rtbcomp]

I've got an 80A supply into my workshop, I run a 3hp compressor in the yard off a dedicated circuit from the consumer unit and another 2hp compressor off one of the ring mains. All at the same time as a 1hp extractor and a few lights.

I do take care that non of the units switch on/off at the same time to avoid excessive surges.

 

[slimjim]

rule of thumb, a 1kw motor driven piston compressor in good condition will give just over 3cfm, thats real cfm, a 3hp motor which is 2.2kw will give a genuine 6-7cfm, despite whats claimed

Air fed masks require oil free air and will make you ill otherwise.

 

[eil]

I have always gone with the 1HP = 3cfm FAD @ 90 psi rule of thumb myself, I have seen some suggest 4/HP on some sites, but with my old ones 3 is about around the mark really.

 

[pedrobedro]

The chap at the local compressor shop where they do contract maintenance on many big set ups estimates the FAD is about 2/3 of the claimed CFM for most diy compressors.

 

[FranV8]

I'd go with that - I thin the 3cfm/hp is a pretty good rule of thumb too.

 

[busastars]

That's cleared up a fair bit, I am considering maybe another compressor something like a 2-2.5hp but there are other options I have seen while google'ing ( I'll keep quiet on that until I have done more research )

Cheers Chaps.

 

[Skillster]

I've run my 3hp on a extension (a very good industrial one!) from the cooker socket without problem. I now have a 16A socket system on a separate MCB into my workshop - just for ease of use really.

 

[the snooper]

the cfm is high on the masks so as to cut out any risks of you being able to pull contaminated air in.

in other words enough air flow to push past the full seal around the mask and face

 

[busastars]

Not sure if I have done the right thing or not but had a punt on ebay and won an Air Fed Mask, guessing I'll need a minimum 2hp compressor to run it, have a look and tell me what you think:

http://cgi.ebay.co.uk/ws/eBayISAPI....4021553&ssPageName=STRK:MEWNX:IT#ht_500wt_949

 

[the snooper]

in my opinion that is a bottle fed mask look at the regulator and the straps that are with it, it doesnt look like a mask for painting but you never know i could be wrong

 

[busastars]

Ahh right, cheers snooper, was a punt.

If it is a bottle fed mask then I would guess it could be converted. If not then how expensive is it to use a bottle for air? Is that a possibility?

Should get it by end of next week so will be able to have a better look.

 

[the snooper]

i could be wrong it just looks like it to me

i would think you could convert it but you would need filters for breathing

cant see it being cheap to use with a bottle it would have to be like a divers bottle so as not to run out in a few minutes

 

[busastars]

May have made bad punt then, but it still should be a full face mask with a pipe going in so just filters to suit,,,,,,Dam this now may get complicated.

What filters are used for an Air Mask, my guess is Water & Oil filter in'line and then fed Air straight from the compressor. Is it as simple as that or more to it?

If it is one for a bottle is it advertised falsely as it is described as an Air Fed Spray Mask.

 

[the snooper]

it could be advertised correctly

air fed = air from any source
spraying = spraying what insecticide ?

could be anything it didnt state paint

 

[Chipper]

Mask filtration, best thing is a three-stage filter, starts at around 5 micron and goes down to 0.01 microns or similar. Your normal compressor traps are like 50 or 25 micron. Could be worth having one of those as well, to save replacing filter elements in the 3-stage, if the kit gets a fair bit of use.
I've got this Kestrel 3-stage one in this sheet, which has the spec and whatnot-
http://www.kestrelequipment.co.uk/K...les/air_breathing_equipment/air_breathing.pdf

 

[eil]

I thought it was off a BA system like Firemen etc use at first but you can connect up to whatever air supply you want apparently.
http://www.keison.co.uk/sabre_airlinebreathingapparatus.shtml