W.S. Tyler SS-31 Ro-Tap® Sieve Shaker

Overview

The W.S. Tyler SS-31 Ro-Tap® Sieve Shaker is a precision-engineered mechanical sieve shaker designed for standardized dry particle size analysis in quality control, R&D, and regulatory testing laboratories. It operates on the proven Ro-Tap® motion principle—combining horizontal circular oscillation (278 cycles/min) with vertical tapping (150 taps/min)—to replicate the manual sieving action defined in ASTM E11, ASTM E323, ISO 3310-1, and USP <786>. This dual-motion profile ensures uniform particle stratification, effective particle passage through apertures, and high reproducibility across repeated analyses. The SS-31 is specifically configured for 12-inch (305 mm) diameter test sieves and delivers over twice the effective screening area of its 8-inch counterparts, making it ideal for low-concentration fine fractions or high-mass samples requiring statistically robust distribution. Its rigid cast-iron base, reinforced steel frame, and bolt-down mounting capability support stable operation under continuous duty—critical for compliance-driven environments including pharmaceutical manufacturing (GMP), cement testing, mineral processing, and polymer QA.

Key Features

• ASTM- and ISO-compliant dual-motion mechanism: 278 oscillations/min + 150 vertical taps/min for repeatable, method-validated separation
• High-capacity 12-inch (305 mm) sieve platform supporting up to four full-height, six intermediate-height, or eight half-height sieves per run
• Digital timer with 0.1-second resolution and 99-minute maximum duration, enabling precise protocol adherence and audit-ready timing logs
• 1/4 HP permanently lubricated induction motor engineered for thermal stability and long-term reliability in high-throughput labs
• Quick-adjust sieve support plate with calibrated locking mechanism—ensures consistent clamping force and minimizes lateral drift during agitation
• Bolt-mount design compatible with laboratory workbenches or vibration-dampening tables to eliminate resonance and ensure measurement integrity
• Interchangeable sieve compatibility: accepts standard W.S. Tyler 12″ full-height, intermediate-height, and half-height frames—including ISO 3310-1–compliant stainless steel and brass mesh configurations

Sample Compatibility & Compliance

The SS-31 accommodates dry, free-flowing granular materials across a broad particle size spectrum—from coarse aggregates (12.5 mm / 1/2 in) down to ultrafine powders (25 µm / No. 500). It is routinely deployed for cement fineness testing (ASTM C184), pharmaceutical excipient characterization (USP <786>), foundry sand analysis (ASTM D225), and mineral ore classification (ISO 9276-2). All operational parameters align with GLP and GMP documentation requirements: timing events are non-volatile and traceable, mechanical motion remains invariant across voltage variants (115V/60Hz, 230V/50Hz, 230V/60Hz), and structural integrity meets ANSI Z245.1 safety standards for laboratory equipment. Optional sound enclosures (W.S. Tyler SoundShell®) reduce ambient noise to ≤65 dB(A), facilitating integration into shared lab spaces without compromising acoustic compliance.

Software & Data Management

While the SS-31 operates as a standalone electromechanical instrument, its deterministic motion profile and digital timer output enable seamless integration into LIMS and ELN workflows via external data capture. When paired with automated balance interfaces or programmable logic controllers (PLCs), weight loss per sieve fraction can be logged with timestamped metadata—including operator ID, sieve stack configuration, and total elapsed time. The device supports FDA 21 CFR Part 11–compliant audit trails when used with validated third-party software platforms that record parameter changes, start/stop events, and calibration verification logs. Routine performance verification follows ASTM E323 Annex A1 protocols, with motion amplitude and tap frequency verified annually using certified metrology tools.

Applications

• Pharmaceutical solid dosage form development: excipient flowability assessment and blend uniformity validation per USP <786>
• Cement and concrete testing: Blaine fineness correlation, residue-on-sieve determination (ASTM C184, EN 196-6)
• Mineral processing: Ore grade control, flotation feed sizing, and tailings characterization
• Food & beverage QA: flour particle distribution, spice grinding consistency, and dairy powder agglomeration analysis
• Advanced materials R&D: ceramic green body homogeneity, battery cathode powder classification, and metal additive manufacturing feedstock screening
• Environmental testing: soil particle size distribution (ASTM D422, ISO 14688-1) and sediment gradation profiling

FAQ

What sieve standards does the SS-31 support?
The SS-31 accepts all W.S. Tyler 12-inch test sieves conforming to ASTM E11, ISO 3310-1, and JIS Z 8801. Both full-height (76 mm) and half-height (38 mm) frames are supported, including stainless steel, brass, and nylon mesh options.
Can the SS-31 be used for wet sieving?
No—the SS-31 is strictly a dry-sieving instrument. Wet sieving requires specialized equipment with liquid containment, drainage, and corrosion-resistant construction not present in the Ro-Tap® platform.
Is calibration certification available?
Yes. W.S. Tyler provides NIST-traceable motion verification reports upon request, documenting oscillation amplitude, tap force, and timer accuracy per ASTM E323 Annex A2.
How does the SS-31 differ from the SS-30 and SS-33 models?
The SS-31 is optimized for 12-inch sieves with higher mass capacity and broader coarse-to-fine range (12.5 mm – 25 µm); the SS-30 handles 8-inch sieves (4.75 mm – 20 µm); the SS-33 performs dual-stack 8-inch sieving simultaneously for comparative or parallel testing.
What maintenance is required?
Routine inspection includes checking belt tension, verifying clamp plate alignment, cleaning dust from motor vents, and confirming timer functionality. No scheduled lubrication is needed—the motor is sealed and permanently greased.