Figure 1: Stainless steel Pall Ring — cylindrical body with stamped windows and inward-bent fingers.
Engineering Alert: When your column runs above 100°C, operates under vacuum, or handles hydrocarbons and high-pressure gas, plastic packings will deform or fail. Stainless steel metal Pall Rings deliver void fractions above 95%, low pressure drop, and the mechanical strength to support deep beds — the industry standard for distillation and scrubbing service.
The Pall Ring is the evolved form of the classic Raschig ring. While it retains the cylindrical shape (height equals diameter), its wall is punched with two rows of windows, and the resulting metal tabs are bent inward toward the center . This simple change transforms performance: the windows create internal surfaces and open pathways that drastically improve liquid distribution, mass transfer efficiency, and throughput while lowering pressure drop .
Stamping the rings from stainless steel strip (rather than casting) gives them high dimensional precision, thin walls, and consistent mechanical strength — all critical for large-scale industrial columns.
Figure 2: Punched windows and inward-bent fingers create internal wetting surfaces.
The table below lists the standard sizes based on SS304 and a wall thickness of 0.3–1.2 mm. Bulk density varies with both material grade and wall thickness; the values shown are for reference .
| Size D×H×T (mm) | Surface Area (m²/m³) | Void Fraction (%) | Bulk Number (pcs/m³) | Bulk Density (kg/m³) |
|---|---|---|---|---|
| 16 × 16 × 0.3 | 362 | 94.9 | 214,000 | 396 |
| 25 × 25 × 0.5 | 219 | 95.0 | 51,940 | 393 |
| 38 × 38 × 0.6 | 146 | 95.9 | 15,180 | 318 |
| 50 × 50 × 0.8 | 109 | 96.0 | 6,500 | 314 |
| 76 × 76 × 1.2 | 71 | 96.1 | 1,830 | 308 |
Data source: compiled from industry standard datasheets (SS304, theoretical values for reference; actual bulk density varies with wall thickness) . Custom sizes (6/10/13/89/100 mm) and non-standard thicknesses are available on request.
Figure 3: Material selection — metal for high temperature & pressure, plastic for corrosion, ceramic for extreme heat.
| Material | Service Temperature | Typical Application |
|---|---|---|
| SS304 / 304L | Up to ~400°C | Clean organics, hydrocarbon fractionation, general service |
| SS316 / 316L | Up to ~400°C | Acid gas absorption, amine/CO2 service, chloride-containing streams |
| Carbon Steel | Up to ~350°C | Cost-sensitive, non-corrosive hydrocarbon service |
| Duplex 2205 / 904L | Up to ~300°C | High chloride / seawater, aggressive corrosion |
| Hastelloy / Titanium / Monel | Alloy-dependent | Severe corrosion, halides, hot acids |
For a deeper dive into the 304 vs 316L decision, see our 304 vs 316L material guide. Available grades include SS304, 304L, 316, 316L, 410, 2205 duplex, 904L, plus carbon steel and exotic alloys .
Metal Pall Rings are specified across separation, absorption, and desorption services — at both atmospheric pressure and under vacuum, where minimizing pressure drop is critical .
Figure 4: Stainless steel Pall Rings being loaded into a distillation column.
Q: When should I choose metal over plastic Pall Rings?
A: Choose metal when operating temperature exceeds 100°C, under vacuum, at high pressure, or with hydrocarbon/organic streams where plastics deform or swell. For corrosive services below 100°C, plastics like PP or PTFE are more economical.
Q: How much packing do I need for my column?
A: Use the bulk number from the table. For a 1.5 m ID column with 4 m bed height of 38mm rings: π × 0.75² × 4 × 15,180 ≈ 107,200 pieces. Contact us with your tower ID and bed height for a precise quote.
Q: Can stainless steel Pall Rings be used with structured packing?
A: Yes. Random metal Pall Rings are often used in the lower or upper beds alongside structured packing, especially in revamps or where redistribution is needed. We can engineer a hybrid bed design for your column.
FXSINO supplies stainless steel metal Pall Rings in SS304, 304L, 316, and 316L in all standard sizes (16/25/38/50/76 mm), with optional carbon steel, duplex, Hastelloy, or titanium. Every batch ships with material mill certificates (MTC to ASTM A240) and dimensional inspection reports.
Contact FXSINO: jackieqiu9202@gmail.com | +86 18507999558
Address : Intersection of Jinguang Avenue and Chongqing Middle Road, Anyuan Industrial Park, Anyuan District, Pingxiang City, Jiangxi
Tel : +86-18507999558
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