Water is as destructive as particulates
The damaging effects of particulate contamination are well-documented. But water can be equally serious in hydraulic and lube oils — reducing component service life by 50 percent or more. Hilco Hilsorb super-absorbent cartridges combine high-efficiency particulate filtration with high-capacity water absorption in a single pleated cartridge.
The saturation point for water in mineral-based hydraulic oil at ambient temperature is 200–300 ppm. But amounts as low as 100 ppm can have serious effects on hydraulic components. Even trace amounts significantly increase wear of highly stressed mechanical components.
How water damages oil systems
Moisture is always present in oil — in emulsified, suspended, or precipitated forms. Water ingression occurs through reservoir breather caps (condensation from volume changes), atmospheric humidity drawn past cylinder rod and wiper seals, water seepage from mechanical failures, and improper oil storage.
Chemical damage
Once water is present in hydraulic fluid, it breaks down additives and alters physical properties. It reacts with oxidation inhibitors to form precipitates and acids. It reacts with long-chain molecules to form polymer films and tribo-oxidation products. It reacts with antiwear additives (ZDDP) to create sulfuric acid and hydrogen sulfide. The result is reduced lubricity, increased viscosity, and corrosion.
Mechanical damage
Water causes bacterial growth that plugs filters, screens, and orifices, and jams control valves. It causes cavitation, reducing pump efficiency and eroding interior surfaces. It corrodes microcracks in bearings and other critical components and causes hydrogen embrittlement of dynamically stressed surfaces. It makes control valves stick and reduces the thickness of lubricating films.
| Oil Type | Parts Per Million | Percent |
|---|---|---|
| Hydraulic | 300 | 0.03% |
| Transformer | 50 | 0.005% |
| Lubricating | 400 | 0.05% |
Hilsorb super-absorbent dryer cartridge
The Hilsorb PD-series pleated dryer cartridge combines high-efficiency particulate filtration with high-capacity water absorption in a single pleated cartridge. The patented pleated construction permits higher flow rates at lower pressure drops than other dryer cartridges. As the cartridge nears saturation with water, pressure drop increases to signal the need for a change — eliminating the need for complicated oil analysis.
Three media grades for different applications
Fine Silt + Water Protection
High-efficiency water and particulate control. Best for fine silt, carbon fines, and applications requiring the tightest particle removal with water absorption. Betaâ‚„ = 200.
High Beta + Max Water
Hydraulic systems requiring a high Beta ratio and maximum water capacity. Ideal for fine particulate filtration combined with the highest water absorption per cartridge.
Heavy Industrial
Low-pressure heavy industrial systems where high reliability is less critical. Systems with larger clearances, heavy contaminants, and components with limited service life. Beta₂₈ = 200.
Hilsorb cartridge specifications
Three cartridge sizes available in each media grade. Applications include insulating oils, hydraulic oils, lube oils, and fuel oils.
| Spec | PD718-12-CN | PD511-12-C | PD310-12-C |
|---|---|---|---|
| Area (sq ft) | 10.36 | 3.65 | 1.82 |
| Flow (GPM) | 10 | 1 | 0.5 |
| Water capacity (ml) | 2,015 | 775 | 245 |
| Dirt capacity (grams) | 107 | 38 | 19 |
| Beta ratio | Bâ‚„ = 200 | Bâ‚„ = 200 | Bâ‚„ = 200 |
| Spec | PD718-03-CN | PD511-03-C | PD310-03-C |
|---|---|---|---|
| Area (sq ft) | 14.5 | 5.07 | 1.93 |
| Flow (GPM) | 10 | 1 | 0.5 |
| Water capacity (ml) | 2,735 | 1,375 | 435 |
| Dirt capacity (grams) | 131 | 46 | 17 |
| Beta ratio | B₂₈ = 200 | B₂₈ = 200 | B₂₈ = 200 |
Physical specifications
| Cartridge | ID (in) | OD (in) | Length (in) | Qty / Box | Ship Wt (lbs) |
|---|---|---|---|---|---|
| PD718-12-CN | 2.56 | 6.25 | 18 | 4 | 18 |
| PD718-12-CRN | 2.093 | 6.25 | 18 | 4 | 18 |
| PD718-03-CN | 2.56 | 6.25 | 18 | 4 | 21 |
| PD718-03-CRN | 2.093 | 6.25 | 18 | 4 | 21 |
| PD511-12-C | 1.75 | 4.68 | 11 | 4 | 7 |
| PD511-03-C | 1.75 | 4.68 | 11 | 4 | 7 |
| PD310-12-C | 1.063 | 2.75 | 9.68 | 4 | 3 |
| PD310-03-C | 1.063 | 2.75 | 9.68 | 4 | 3 |
How to specify: PD (Pleated Dryer) + size (310 = 3×10, 511 = 5×11, 718 = 7×18) + media (-12, -01, -03) + feature (C = centertube, CR = centertube with reducer).