Quick Take
If your shop needs to remove water from compressed air, separate oil from cutting fluid, or change filter socks in a liquid filtration setup, these four products span three distinct jobs. The first decision is matching the product to the task rather than picking the one with the lowest or highest price.
The 3/4" NPT 4-Stage Air Dryer is the compressor-side pick. The PreAsion 208-240V Oil-Water Separator is the machine-tool investment. The two Duda Energy filter bag lots handle bulk liquid filtration, with welded and sewn seam options.
Listed Price Comparison
| Product | Listed Price | Price Bar |
|---|---|---|
| PreAsion 208-240V Oil-Water Separator | $1,703.84 | |
| 3/4" NPT 4-Stage Air Dryer | $158.00 | |
| Duda Energy Welded Filter Bags | $327.83 | |
| Duda Energy Sewn Filter Bags | $316.00 |
The listed price spread runs from $158 to $1,703.84, so let the task define the budget.
Decision Matrix
| Product | Best For | Key Listed Spec |
|---|---|---|
| PreAsion Oil-Water Separator | Machine-tool coolant oil recovery | 208-240V, 3PH, oil recovery and sludge valve |
| 3/4" NPT 4-Stage Air Dryer | Compressor air drying for plasma cutting and paint spray | 240 PSI max, 4-stage, auto drain |
| Duda Energy Welded Filter Bags | Liquid filtration where fiber-free seams matter | Size #4, 0.5 micron, 50-pack, plastic flange |
| Duda Energy Sewn Filter Bags | General liquid and biofuel filtration | Size #4, 0.5 micron, 50-pack |
3/4" NPT 4-Stage Industrial Air Dryer Compressor Water Separator
At $158, this is the entry point if you need dry air for plasma cutting or spray painting. The two 3/4" NPT air ports and 1/4" NPT gauge port are built for high-pressure lines up to 240 PSI, and the four-stage layout pairs filter stages with desiccant drying and an auto drain. The unit is not for horizontal installation, so factor in vertical clearance. You'll also need to monitor the desiccant beads, especially if upstream compressed-air lines already contain heavy moisture, because that will shorten replacement intervals.
PreAsion 208-240V Industrial Oil Water Separator 3PH Cutting Fluid Skimmer
At $1,703.84, this is the largest investment here, and it is aimed at shops running machine tools on 208-240V three-phase power. The unit separates floating oil from cutting fluid, helping the coolant last longer and keeping cutting tools accurate. An oil drainage route lets you reuse captured oil, while a cleaning valve removes sludge from the tank bottom. Given the price, it only makes sense if you face real oil-loading problems in a machine-tool sump. Confirm your power supply and sump access before committing to this level.
Duda Energy Welded Industrial Filter Sock Bags
These welded sock bags, $327.83 for 50 Size #4 bags, use heat-bonded seams to avoid needle holes and thread contamination. The fused edges provide a fiber-free finish, which is helpful for fuel, oil, WVO, and other liquids where stray fibers are a concern. Each bag is 4" x 14" with a 1/2 - 0.5 micron rating and includes a plastic ring flange with handles for easy removal from a filter bag housing. The main limitation is that the welded construction carries a higher listed price than the sewn option, and you need a housing that accepts Size #4 bags.
Duda Energy Sewn Industrial Filter Sock Bags
At $316 for 50 Size #4 bags, the sewn filter bag lot gives you the same 4" x 14" dimensions and 1/2 - 0.5 micron rating as the welded set, but with sewn seams and a lower listed price. It is positioned for water, liquid biodiesel, WVO, oil, dust, fuel, and diesel, making it a general-purpose liquid filtration option. The trade-off is that the seams include needle holes, so if you're filtering fluids where fiber migration or thread contamination would be a problem, the welded version is the safer pick. For everyday biofuel or water filtration, the sewn bags are a straightforward choice.
Final Recommendation by Use Case
- Choose the 3/4" NPT 4-Stage Industrial Air Dryer Compressor Water Separator if you are treating compressed air before plasma cutting or paint spray.
- Choose the PreAsion 208-240V Industrial Oil Water Separator if you are protecting cutting fluid in machine tools and have the 208-240V three-phase power to run it.
- Choose the Duda Energy Welded Filter Sock Bags if liquid filtration must avoid fiber contamination.
- Choose the Duda Energy Sewn Filter Sock Bags for general-purpose liquid filtration.
No single product handles every filtration separation task. Pick the air dryer for compressor air duty, the oil separator for machine-tool coolant, and the bag kits for bulk liquid filtration.
