Sheave & Belt Source-Aware Field Screen

How It Works

1. Enter What You Can Measure

   Driver RPM, driver and driven sheave outside diameters, and center distance if you have it. Use OD as a field stand-in only; catalog pitch diameters control final speed and belt-length review.

2. Pick the Driven Equipment

   Select pump, fan, blower, conveyor, auger, PD pump, recip compressor, or machine tool so the app can show the right source-boundary prompts. Centrifugal pump and fan rows use affinity-law screening only.

3. Identify the Belt Section

   Choose the known section or enter a top-width measurement. The match is a local prompt against A, B, C, D, E, 3V, 5V, 8V, and fractional-HP families, not a certified ARPM table reproduction.

4. Compare to Expected

   Optional expected and observed RPM fields help expose possible sheave or motor changes. The current-entry field is a direct present-state overload prompt, not a design approval.

5. Identify the Bushing

   Use face bolts, flange-edge bolts, set screws, split clues, and stamped codes to classify likely QD, Taper-Lock, fixed-bore, or split-taper patterns. Exact bore, keyway, torque, hardware, and installation stay with the current manufacturer catalog.

6. Read the Source Boundaries

   The status combines local belt speed, wrap, sheave-size, and pump/fan prompts. Treat it as a measurement checklist and source-gap screen before catalog, OEM, guarding, lockout, and qualified review.

Built For

• Maintenance mechanic screening why amps are higher after a sheave swap before pulling current pump or fan data
• Millwright comparing a replacement sheave against field measurements before catalog verification
• Plant engineer listing source gaps before a proposed pump or fan speed change is reviewed
• Reliability tech checking likely changed conditions after equipment behavior shifted
• Foreman documenting that manufacturer pitch diameter, bushing, guard, and installation checks are still open
• Pump or fan tech deciding which curve, motor, and OEM limits must be reviewed next

Features & Capabilities

Field-First Two-Mode Interface

Field Mode keeps the measurement workflow compact. Advanced Mode exposes the local cross-section reference table. Both modes use the same calculation module and source-boundary warnings.

Belt Section Identification by Top Width

Caliper and tape-rule tolerances produce local confidence prompts for common V-belt families. Ambiguous rows are labeled instead of forced into a single answer.

Affinity-Law Source Prompt

For centrifugal pumps and fans, the app shows flow, head/static pressure, and power-change prompts. Actual acceptance requires pump or fan curves, system curve, motor/VFD data, NPSH or stall review, and qualified review.

Sheave Part Number Pattern Decoder

Pattern-matches common designators such as BK, 5V, and Taper-Lock 4-digit codes. It returns likely meaning and search context, not an exact replacement part.

Bushing Identification Flow

Field cues and stamped codes identify likely QD, Taper-Lock, fixed-bore, and split-taper families while keeping bore, keyway, torque, fit, and installation source gaps visible.

Field Cheat Codes Library

Plain-language symptoms surface likely causes and next checks. These are troubleshooting prompts, not repair instructions or return-to-service approval.

Next Measurement Prompts

When an input is missing, the app lists the next measurement, why it matters, and how to capture it for later catalog, OEM, or engineering review.

Confidence Levels on Outputs

Belt-section matches, bushing clues, part-code decoding, and inferred-change messages carry high, medium, or low confidence labels.

Visual Drive Geometry

A live geometry view shows sheaves, belt loop, and wrap-angle prompts so users can see why ratio and center distance matter before final design review.

Comparison

Assumptions

• Sheave outside diameter is used as a working approximation for pitch diameter; catalog pitch diameter controls final review.
• Belt slip is shown as a typical 2 percent context prompt only.
• Affinity-law projections apply only as local prompts for centrifugal pumps and fans.
• Wrap angle assumes a two-sheave external-tangent layout with no idler.
• Belt section identification tolerance is plus/minus 1/32 inch for caliper measurement and plus/minus 1/16 inch for tape-rule measurement.
• Bushing identification rules are heuristic; stamped catalog code and current manufacturer data control final decisions.

Limitations

• Does not output exact manufacturer part numbers or replacement approval.
• Does not reproduce protected ARPM/MPTA tables or certify local belt-section rows.
• Does not evaluate pitch diameter, sheave material, balance, bore, keyway, torque, installation, overhung load, or OEM limits.
• Does not evaluate guarding, lockout/tagout, pinch points, exposed rotating parts, emergency stops, or safe-work procedures.
• Does not replace pump curves, fan curves, system curves, NPSH, stall, VFD/starter, or motor protection review.
• Synchronous belt tooth capacity and pulley pitch matching are outside scope.

References

• MPTA-B13I-2013-R2025 rim-speed source pointer.
• ARPM-IP-20-2022-SOURCE and ARPM-IP-22-2021-SOURCE protected standard listings.
• GATES-HEAVY-DUTY-VBELT-MANUAL manufacturer source pointer.
• MARTIN-TAPER-BUSHINGS-CATALOG bushing source pointer.
• NEMA-MOTORS-GENERATORS-SOURCE motor context pointer.
• AMCA-201-23-SOURCE and DOE-PUMP-SOURCEBOOK-2006 pump/fan context pointers.
• OSHA-1910-219-POWER-TRANSMISSION-SOURCE and OSHA-1910-147-LOTO-2026 safety source pointers.
• NIST-SP811-B8 unit-conversion pointer.

Frequently Asked Questions