LVLP Versus HVLP Spray Guns
Quick info on the difference between "high volume low pressure" and "low volume low pressure" spray equipment. August 8, 2008
Question
I know LVLP means "low volume low pressure" but the only place I have seen that sells LVLP guns is the Grizzly catalog. Is this some alternative to HVLP? Is it supposedly better for some reason?
Forum Responses
(Finishing Forum)
From contributor A:
There are a lot of LVLP guns out there. I have been tempted to buy one just to see how much difference there is, but I guess I'm not curious enough. I've seen small automated microliter spray guns paint bolt heads with nearly no overspray but on large surfaces I doubt this is the case.
From contributor B:
A lot of LVLP guns are labeled HVLP. The original HVLP conversion guns used around 22 CFM @ 50PSI and "converted" it to 10 PSI at the air cap. The problem was that most people didn't have a 7.5 HP compressor with an 80 gallon tank to keep up with the gun.
The gun manufacturers, through air cap design, came up with air caps that would atomize thin coatings (wood coatings, for example) with 15 - 29 PSI and as low as 6 CFM. They were still able to stay below 10 PSI at the air cap and therefore were considered acceptable as HVLP by regulatory agencies but they are actually LVLP.
From the original questioner:
The $100 Porter-Cable HVLP gun that I bought for spraying onesies and twosies - that suggests 40-45# incoming - is one of the older style HVLP guns? That is fine, as our shop has a nice horse of a compressor.
From contributor C:
LVLP and HVLP are basically the same. Both work with 10 PSI or less at the air cap, and anywhere from (usually) 20 - 40 PSI inlet pressure. Depending on the manufacturer's marketing, everything below 7 - 10 CFM air requirement is usually called LVLP, and everything above that (with a 10 PSI or less air cap pressure) is called HVLP. LVLP guns generally don't have as high material flow rates and fan widths as wide as the HVLP guns which consume more air. You can't break the laws of physics. LVLP guns can be used for on-site and touch up work because they can often be run from a small compressor such as those used to run a nailer (5-6 CFM). HVLP guns generally work better in a production environment because of their higher material flow rates and wider fan widths.
