What Is PVDF Pall Ring Packing? Material Characteristics, Applications and Selection Boundaries

PVDF Pall Ring is a fluoropolymer random packing that combines the open, windowed structure of Pall Ring packing with polyvinylidene fluoride (PVDF) construction. It is mainly considered for packed towers where corrosion resistance, polymer construction and moderate-to-elevated operating temperatures are important, while the process still requires the hydraulic and mass-transfer characteristics of random Pall Ring packing.

DAIER’s engineering database identifies PVDF Pall Ring as a separate Plastic / Random Packing product family and includes 25, 38 and 50 mm product nodes.

The primary engineering question for this page is:

What does PVDF material add to Pall Ring packing, where is this product useful, and what are its main application boundaries?

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1. What Is PVDF Pall Ring?

PVDF Pall Ring is a random tower packing manufactured from polyvinylidene fluoride.

Its basic packing geometry follows the Pall Ring concept:

• cylindrical body;
• multiple wall openings;
• internal formed sections;
• open gas and liquid pathways.

The individual packing elements are loaded randomly into the packed bed.

The product therefore combines two engineering characteristics:

Pall Ring geometry for gas-liquid contacting

with

PVDF material for chemically demanding plastic-packing service

These two characteristics should be evaluated separately.

A suitable Pall Ring geometry made from the wrong material is still unsuitable.

Likewise, choosing PVDF does not automatically mean Pall Ring is the correct packing geometry for every tower.

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2. What Does Pall Ring Geometry Do?

The Pall Ring was developed from the simpler Raschig Ring concept.

Instead of using a mostly closed cylindrical wall, Pall Ring introduces openings that allow gas and liquid to move:

• through the center;
• through the side walls;
• around neighboring packing elements.

Internal formed sections also provide additional surfaces that may become wetted during operation.

The purpose is to improve the use of the space inside the packing element while maintaining an open random-packed bed.

This geometry can support a useful balance between:

• gas-liquid contact;
• liquid drainage;
• gas passage;
• hydraulic capacity.

Actual tower performance still depends on operating conditions.

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3. What Makes PVDF Different?

PVDF is a fluoropolymer.

Its role in Pall Ring packing is primarily to extend the material-selection envelope beyond what some conventional plastics can provide.

PVDF may be considered when a process requires:

• stronger chemical resistance than common commodity plastics can provide;
• greater temperature margin than some standard thermoplastics;
• non-metallic tower packing;
• molded random packing rather than ceramic or metallic construction.

This gives PVDF Pall Ring a specific product position:

Open Random Packing Geometry + Fluoropolymer Material Capability

PVDF itself does not create higher mass-transfer efficiency simply because it is a higher-performance polymer.

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4. PVDF Pall Ring Is a Material-Specific Product Node

This distinction is important for SEO, procurement and engineering.

“Pall Ring” identifies the packing geometry.

“PVDF” identifies the material.

Therefore, PVDF Pall Ring is not merely another synonym for:

• Plastic Pall Ring;
• PP Pall Ring;
• PTFE Pall Ring;
• PVDF Raschig Ring.

It is a specific Material × Product Geometry combination.

DAIER’s engineering database independently lists PVDF Pall Ring in 25, 38 and 50 mm configurations, confirming that it is treated as its own product family rather than as a generic plastic-packing label.

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5. Where Is PVDF Pall Ring Typically Considered?

PVDF Pall Ring can be evaluated in packed towers where several requirements occur together:

• corrosive gas or liquid service;
• random packing is suitable;
• polymer construction is preferred;
• Pall Ring geometry provides adequate hydraulic and mass-transfer performance;
• process conditions justify PVDF material.

Potential categories include suitable:

• chemical absorption towers;
• gas scrubbers;
• stripping towers;
• specialty chemical processing;
• corrosive gas-treatment equipment.

The application name alone is not enough to approve the product.

For example, two scrubbers may have very different:

• chemicals;
• concentrations;
• temperatures;
• gas loads;
• fouling conditions.

One may suit PVDF Pall Ring while the other may not.

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6. Chemical Resistance Is the Main Reason to Evaluate PVDF

PVDF is often considered because material compatibility has become an important project constraint.

But the phrase:

“corrosion-resistant plastic”

is not enough for final selection.

The engineer should identify:

• exact chemical species;
• concentration;
• operating temperature;
• solvent exposure;
• oxidizing components;
• impurities;
• cleaning chemicals.

Material compatibility should be checked against the actual process stream.

Do not select PVDF only from:

• pH;
• “acidic”;
• “alkaline”;
• “corrosive.”

Those descriptions are too broad.

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7. Temperature and Chemical Exposure Must Be Considered Together

Polymer performance is affected by both:

temperature

and

chemical environment.

A PVDF packing that performs acceptably at one temperature in one chemical system may have a different operating boundary in another.

DAIER’s engineering tool internally classifies PVDF Pall Ring as a higher-temperature plastic-packing option than common PP packing, but that value is a preliminary engineering-screening parameter rather than a universal production guarantee.

Final specification should therefore confirm:

• actual PVDF resin grade;
• normal operating temperature;
• maximum continuous recommended temperature;
• short-term upset temperature;
• chemical exposure at those temperatures.

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8. PVDF Material Does Not Define Tower Efficiency

One common misunderstanding is to treat material grade as a performance ranking.

For example:

PVDF Pall Ring is not automatically more efficient because PVDF is a more specialized polymer.

Mass-transfer performance depends on factors such as:

• packing geometry;
• packing size;
• liquid distribution;
• wetting;
• gas flow;
• liquid flow;
• packed height;
• fluid properties.

PVDF mainly changes the material compatibility boundary.

The Pall Ring geometry still performs the gas-liquid contacting function.

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9. Liquid Wetting Still Matters

The geometric surface of a packing element becomes useful only when liquid effectively wets that surface.

Actual wetting behavior can depend on:

• liquid composition;
• surface tension;
• viscosity;
• liquid load;
• distributor performance.

Therefore, the correct engineering chain is not:

PVDF → good corrosion resistance → automatically high mass transfer.

It is:

Material Compatibility + Suitable Geometry + Good Liquid Distribution + Appropriate Operating Load

All four matter.

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10. Gas Scrubber Applications

PVDF Pall Ring may be considered in chemical scrubbers where:

• corrosive service limits standard plastic materials;
• random packing is hydraulically appropriate;
• gas-liquid contact is required;
• polymer construction is preferred.

Possible examples may include compatible:

• process exhaust treatment;
• acid-gas scrubbing;
• chemical vapor treatment;
• specialty manufacturing exhaust systems.

However, the final product selection still needs information on:

• gas composition;
• scrubbing liquid;
• temperature;
• solids;
• liquid circulation rate;
• tower diameter.

“Scrubber tower” by itself is not a complete specification.

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11. Absorption Applications

PVDF Pall Ring can also be evaluated in gas absorption systems.

The open Pall Ring geometry can provide:

• wetted contacting surfaces;
• interconnected gas passages;
• repeated liquid redistribution.

PVDF becomes relevant when the absorbing liquid or gas environment requires its material properties.

The final engineering decision must still confirm:

• required absorption duty;
• gas flow;
• liquid flow;
• allowable pressure drop;
• bed height;
• tower diameter.

PVDF determines whether the material survives the process.

It does not determine the required packed-bed design by itself.

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12. Stripping Applications

In compatible stripping service, PVDF Pall Ring may provide:

• corrosion-resistant plastic construction;
• open gas pathways;
• liquid drainage;
• gas-liquid contact.

But stripping applications may impose different conditions from absorption systems, including:

• higher gas or air rates;
• different operating temperatures;
• different liquid properties.

The same PVDF Pall Ring should therefore not be assumed to behave identically across all tower duties.

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13. Fouling Is a Separate Selection Boundary

PVDF can resist chemical attack in suitable applications, but it does not prevent fouling.

A Pall Ring bed can still accumulate:

• solids;
• salts;
• scale;
• crystals;
• biological deposits;
• sticky process material.

Deposits may form:

• on ring surfaces;
• around wall openings;
• on internal formed sections;
• between neighboring packing elements.

Therefore:

chemical resistance and fouling resistance are not the same thing.

A chemically durable packing can still become hydraulically restricted.

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14. Severe Crystallization May Favor Another Geometry

Pall Ring provides useful internal structure for mass transfer.

Those same internal surfaces can become deposition locations in strongly crystallizing service.

If the process contains severe:

• salt precipitation;
• crystal growth;
• scale formation;

the engineer may need to prioritize:

• larger flow passages;
• simpler geometry;
• easier cleaning.

In such cases, another random-packing geometry may be more appropriate even if PVDF remains the correct material.

This is an important application boundary for PVDF Pall Ring.

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15. Solids and Suspended Material Require Caution

A process containing suspended solids should not automatically use conventional Pall Ring merely because the polymer is compatible.

Solids may accumulate within the packed bed and gradually affect:

• pressure drop;
• liquid distribution;
• gas capacity;
• effective contacting area.

Before specifying PVDF Pall Ring in dirty service, identify:

• solids concentration;
• particle size;
• deposit characteristics;
• cleaning method;
• shutdown frequency.

The correct material cannot compensate for the wrong packing geometry.

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16. Product Size Is Available—but Is Not the Primary Intent of This Page

DAIER’s engineering database currently identifies PVDF Pall Ring in:

• 25 mm;
• 38 mm;
• 50 mm. 

These sizes indicate that PVDF Pall Ring is available across several common industrial packing classes.

However, this page does not attempt to decide which size is universally better.

Size selection should be handled according to:

• tower diameter;
• gas load;
• liquid load;
• fouling condition;
• mass-transfer requirement;
• allowable pressure drop.

This keeps the product-entity decision separate from dedicated size-selection content.

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17. Why Supplier-Specific Data Matter

Commercial names such as “Pall Ring” describe a general packing family.

Actual products can still differ in:

• wall thickness;
• opening geometry;
• internal structure;
• element weight;
• bulk density;
• dimensional tolerance.

This matters even more for specialized polymers such as PVDF.

Therefore, final procurement should use the supplier’s approved datasheet rather than assuming that:

all 50 mm PVDF Pall Rings are technically identical.

Manufacturer-specific data should be confirmed before final engineering approval.

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18. Mechanical Properties Also Matter

Material selection is not only about corrosion.

The packing must also tolerate:

• transportation;
• loading;
• normal operating forces;
• maintenance handling.

Compared with brittle ceramic packing, molded polymer packing behaves differently during handling.

But polymer construction also introduces its own:

• temperature-dependent mechanical behavior;
• deformation considerations;
• long-term load concerns.

Therefore, final product approval should consider both:

chemical compatibility

and

mechanical suitability.

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19. Tower Internals Still Control Bed Performance

PVDF Pall Ring does not operate independently.

A packed tower also depends on:

• packing support;
• liquid distributor;
• redistributor where required;
• hold-down arrangement;
• gas inlet configuration.

Poor liquid distribution can produce:

• channeling;
• uneven wetting;
• unused packing area.

Installing a chemically superior packing cannot correct a fundamentally poor distributor.

The packed bed should therefore be treated as one part of the complete tower-internals system.

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20. Support Grid Compatibility

The support grid must:

• retain the selected packing;
• carry the operating bed load;
• provide sufficient open flow area.

When PVDF Pall Ring replaces another product, check:

• existing support opening;
• packing dimensions;
• bulk density;
• wet bed load.

If the new packing is smaller than the existing product, the support may require modification.

This is particularly important in retrofit projects.

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21. Hold-Down Requirements

Lightweight plastic random packing can move under certain abnormal hydraulic conditions.

Where project conditions justify a hold-down device, its function is to:

restrain excessive packing movement

not:

compress the packed bed.

The requirement depends on:

• packing density;
• gas velocity;
• tower configuration;
• upset conditions.

It should be evaluated separately from material compatibility.

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22. When Is PVDF Pall Ring a Strong Candidate?

PVDF Pall Ring deserves stronger consideration when:

• Pall Ring geometry is appropriate for the process;
• polymer packing is preferred;
• conventional plastic compatibility is insufficient;
• PVDF is compatible with the actual chemical stream;
• operating temperature falls within the verified PVDF product limit;
• fouling is manageable;
• random packing provides the required process performance.

Its strongest engineering identity is therefore:

Fluoropolymer Chemical Compatibility + Open Pall Ring Geometry + Random Packing Operation

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23. When Should Engineers Look Beyond PVDF Pall Ring?

PVDF Pall Ring may become less attractive when:

• the chemistry is incompatible with the selected PVDF grade;
• operating temperature exceeds the verified product limit;
• severe crystallization or solids dominate;
• extreme hydraulic capacity requires a more open geometry;
• demanding low-pressure-drop separation favors structured packing;
• another material provides adequate compatibility with lower project complexity.

A technically correct product is not necessarily the correct product for every tower.

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PVDF Pall Ring Application Boundary Table

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24. What Should Be Confirmed Before Ordering?

A useful PVDF Pall Ring specification should confirm:

• product name: PVDF Pall Ring;
• PVDF resin grade;
• nominal size;
• actual element dimensions;
• bulk density;
• specific surface area;
• void fraction;
• quantity required;
• operating temperature;
• chemical compatibility;
• packing method;
• net weight;
• gross weight.

Project information should include:

• tower ID;
• packed height;
• gas composition;
• liquid composition;
• chemical concentration;
• operating temperature;
• gas flow;
• liquid flow;
• fouling or solids information.

These data help prevent a material-compatible product from being applied under unsuitable hydraulic conditions.

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25. Common Selection Mistakes

Treating PVDF as a Performance Upgrade

PVDF primarily changes material capability, not guaranteed tower efficiency.

Selecting PVDF Only from pH

Actual chemicals, concentration and temperature must be reviewed.

Assuming Every PVDF Pall Ring Is Identical

Supplier-specific geometry and physical properties can differ.

Ignoring Fouling Because the Material Is Corrosion-Resistant

Chemical durability does not prevent plugging or scaling.

Ignoring Liquid Distribution

Poor distribution can reduce the effective use of the packed bed.

Treating Size as the Only Engineering Variable

Material, operating load, tower diameter and fouling also matter.

Using Tool Screening Values as Final Datasheet Guarantees

DAIER’s engineering database confirms the product family and 25/38/50 mm nodes, but final procurement specifications should be based on the approved production datasheet.

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Frequently Asked Questions

What is PVDF Pall Ring?

PVDF Pall Ring is a fluoropolymer random tower packing that combines open Pall Ring geometry with PVDF construction.

Is PVDF Pall Ring a random packing?

Yes. DAIER’s engineering database classifies PVDF Pall Ring under Plastic / Random Packing.

What sizes does DAIER's engineering database contain?

The current database contains 25, 38 and 50 mm PVDF Pall Ring nodes.

What is the main reason to use PVDF Pall Ring?

The main reason is to combine Pall Ring gas-liquid contacting geometry with the material capabilities of PVDF where the actual process requires them.

Does PVDF Pall Ring automatically provide better mass transfer than standard plastic Pall Ring?

No. Material grade does not by itself determine mass-transfer performance.

Can PVDF Pall Ring be used in scrubbers?

It can be a strong candidate for suitable chemical scrubbers when PVDF is compatible with the actual gas, liquid, temperature and operating conditions.

Is PVDF Pall Ring suitable for fouling service?

Moderate fouling may be manageable with appropriate product and size selection, but severe scale, crystallization or solids may favor a more open geometry.

What information is needed before specifying PVDF Pall Ring?

At minimum, provide process chemistry, concentration, temperature, tower diameter, gas and liquid loads, packed height and fouling information.

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Selection Takeaway

PVDF Pall Ring is best understood as a material-specific Pall Ring product—not as a generic “premium plastic packing.”

Its engineering value comes from combining:

PVDF Material Capability

with

Open Pall Ring Gas-Liquid Contacting Geometry

The correct preliminary decision sequence is:

Process Chemistry → Temperature → Confirm PVDF Compatibility → Confirm Pall Ring Geometry Is Appropriate → Check Fouling → Confirm Size and Hydraulic Conditions → Verify Supplier Datasheet

The key principle is:

Choose PVDF Pall Ring when both PVDF material and Pall Ring geometry match the actual process requirement. Material resistance alone is not enough, and packing geometry alone is not enough.