RO-TAP®: The Sound-Enclosed Test Sieve Shaker for Abrasives

For reliable quality control in industry, the precise determination of particle size distribution is essential. If you are looking to purchase a high-performance tapping test sieve shaker, NEXOPART offers the global industry standard with the W.S. TYLER® RO-TAP® series. These test sieve shakers combine a horizontal circular motion with a vertical tapping impulse. This unique two-dimensional operation guarantees reproducible results, even with challenging bulk materials that tend to interlock. Particularly in industries working according to strict standards such as the FEPA standard, the RO-TAP® series is the preferred choice for dry sieving applications within a measuring range of 20 µm to 100 mm. Explore our models below and find the right system for your laboratory.
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RO-TAP®: The Sound-Enclosed Test Sieve Shaker for Abrasives

Test Sieve Shakers for the Highest Industrial Requirements

In industrial laboratories across the construction materials, chemical, and raw materials industries, users are faced daily with the challenge of analyzing heterogeneous samples in a material-appropriate, time-efficient, and above all standards-compliant manner. A test sieve shaker must not only deliver precise and reproducible results, but also withstand the demanding conditions of everyday laboratory work.

For many materials, mechanical sieving with a tapping motion is mandatory in order to obtain valid conclusions about product quality.

Test Sieve Shaker for Abrasives: A Specialist for Extreme Conditions

 

Particular challenges arise when analyzing extremely hard, angular, or highly abrasive bulk materials. When selecting a test sieve shaker suitable for abrasive materials, mechanical robustness becomes the primary focus.

Abrasives and blasting media require high impact forces to break up particle agglomerates and prevent clogging of the sieve mesh.

W.S. TYLER® RO-TAP® machines are specifically engineered for these conditions. Their heavy-duty steel housing with a high-quality finish and robust guide plates ensures long-term durability. The powerful vertical tapping impulse prevents angular abrasive particles from becoming lodged in the mesh, ensuring effective cleaning and a correct sieving process.

The FEPA standard (Fédération Européenne des Fabricants de Produits Abrasifs) explicitly recommends the RO-TAP® as the reference system for testing abrasive grain sizes.

Tapping Test Sieve Shaker vs. Vibrating Sieve Shaker: Choosing the Right Analysis Method


When equipping a testing laboratory, one key question often arises: tapping sieve shaker vs. vibratory sieve shaker. Both technologies have their specific areas of application but differ fundamentally in their motion dynamics.

A vibratory sieve shaker operates with a three-dimensional throwing motion that propels the material upward and distributes it across the sieve surface through a simultaneous rotational movement. This method is ideal for free-flowing, light to medium bulk materials.

A tapping sieve shaker, on the other hand, operates in two dimensions. RO-TAP® models generate precisely 278 (±10) rotations per minute combined with 150 (±10) tapping impulses per minute through a mechanical hammer acting from above.

This additional impact on the cork stopper of the lid is crucial for:

  • Particles prone to interlocking (e.g. needle-shaped or angular grains)
  • Strongly electrostatically charged powders
  • Heavy and abrasive bulk materials
  • Applications governed by standards that define RO-TAP® as the reference method

Whenever strict compliance is required for challenging materials, the tapping sieve method is often the only way to achieve reproducible separation results.

The W.S. TYLER® RO-TAP® Product Range in Detail

 

Choosing the right model depends largely on the required sieve diameters, sample volume, and laboratory infrastructure. NEXOPART offers three main versions, all featuring proven plug-and-play operation and a digital timer (0–99 minutes).

Ro-Tap Sieve Shaker RX-29 CE from WS Tyler with Sound absorbing cupboard

RO-TAP® RX-29: The Standard for 200 mm test sieves


Designed for sieve diameters of 200 mm or 203 mm (8"), covering a measuring range from 20 µm to 50 mm with a maximum sample load of approx. 3 kg.

The sieve stack (max. 8.7 kg) can hold:

  • up to 7 sieves at 50 mm height
  • up to 13 sieves (without sealing rings) at 32 mm height

Power consumption: 2.9 A (230 V)

RO-TAP® RX-30: For large volumes and 300 mm test sieves


The RX-30 is designed for larger sample volumes and coarser materials. The measuring range extends from 25 µm to 100 mm. It accommodates sieve diameters of 300 mm or 305 mm (12"), with a maximum sieve stack weight of 8.7 kg.

RO-TAP® RX-94: Double throughput


For laboratories with very high sample volumes, the RX-94 allows two sieve stacks (200 mm / 8") to be processed simultaneously, effectively doubling throughput within the same time.

Test Sieve Shaker with CE Certification, Sound Enclosure, and Operator Safety

 

Due to their design, mechanical tapping sieve shakers generate significant noise emissions. Without soundproofing, a standard RO-TAP® machine (e.g. RX-29-10 or RX-30-10) reaches around 86 dB.

To comply with modern safety regulations and the Machinery Directive, sound insulation is essential. NEXOPART therefore offers CE-compliant versions (RX-29 CE and RX-30 CE) integrated into a robust sound enclosure.

The enclosure (dimensions: 890 x 610 x 740 mm) reduces noise—for example when sieving gravel—to approximately 78 dB. This reduction of 8 dB significantly relieves laboratory personnel and enables continuous operation without additional hearing protection.

The total weight of the CE models including enclosure is approx. 124 kg, providing additional operational stability.

RO-TAP® Test Sieve Shakers: Efficiency and Documentation

 

A key factor in economic efficiency is the durability of the mechanical components. The investment pays off through low maintenance, high reliability under multi-shift operation, and standard-compliant results that prevent costly production errors.

Furthermore, NEXOPART supports audit processes in highly regulated industries (such as pharmaceuticals, food, or critical construction materials) with comprehensive certification options.

Available options include inspection certificates (3.1 according to DIN EN 10204 or SAE J444) and full IQ/OQ documentation. This ensures complete traceability and validation of your sieve analysis processes.

FAQ about tapping test sieve shaker

What voltage do RO-TAP® models require?

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The standard models operate at 230 V, 50 Hz with a current consumption of 2.9 A. For the RX-29 model, an additional 115 V, 60 Hz version (4.4 A) is available.

What does sound insulation mean for test sieve shakers?

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Sound insulation refers to design measures that reduce the noise emissions generated during the sieving process. This is particularly important for test sieve shakers with mechanical rotation and vertical tapping motion, as the recurring motion impulses can create elevated noise levels in everyday laboratory use.

Can I use the RO-TAP® for wet sieving?

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No. The W.S. TYLER® RO-TAP® tapping test sieve shakers (RX-29, RX-30, RX-94) are designed exclusively for dry sieving applications.

How is the sieve stack clamped?

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The sieve stack is secured using a height-adjustable steel support plate and robust adjustable clamping levers. The lid is equipped with a special cork stopper onto which the mechanical hammer transfers the vertical tapping impulse.

Which spare or wear parts are relevant?

L


The cork stopper in the lid is a typical wear part. It absorbs the hard impact of the hammer and protects the metal sieve stack. It can be replaced quickly, easily, and cost-effectively whenever required.

How does the RX-94 differ from the CE models?

L


The RX-94, designed for double throughput, is not CE-compliant due to its open design and is supplied without a sound enclosure as standard. It is specifically intended for environments where the noise level (86 dB) is not critical or where external soundproof cabins are already available on site.

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