Turbomachinery Axial Protection Solution — Bently Nevada 991-25-50-02-05 | 3300 Series Thrust Position Transmitter
Where This Product Is Used
The Bently Nevada 991-25-50-02-05 is a precision thrust position transmitter engineered for continuous axial displacement monitoring in rotating machinery. It is widely deployed across:
- Steam & Gas Turbines — Detects rotor axial shift before catastrophic blade-to-casing contact occurs
- Centrifugal Compressors — Monitors thrust bearing wear in ethylene, ammonia, and LNG compression trains
- Boiler Feed Pumps — Provides early warning of impeller axial migration in high-pressure utility applications
- Expanders & Turboexpanders — Tracks axial position in cryogenic and refinery service expanders
- Gearboxes & Integrally Geared Compressors — Monitors thrust collar position under variable load conditions
Wherever API 670 machinery protection is mandated, the 991-25-50-02-05 is the transmitter of choice for plant engineers and OEM integrators.
Technical Specifications
| Part Number | 991-25-50-02-05 |
| Series | Bently Nevada 3300 Series |
| Function | Thrust / Axial Position Transmitter |
| Output Signal | 4–20 mA (2-wire, loop-powered) |
| Measurement Range | ±25 mil (±0.635 mm) standard |
| Cable Length | 5.0 m (extension cable included) |
| Probe Type | 25 mm proximity probe |
| Operating Temperature | −40 °C to +121 °C (probe); −35 °C to +66 °C (driver) |
| Supply Voltage | 18–30 VDC |
| Enclosure Rating | IP66 / NEMA 4X |
| Approvals | CE, ATEX, IECEx (consult datasheet for zone classification) |
| Weight | 440 g (approx.) |
| Manufacturer | Bently Nevada (Baker Hughes) |
Why Engineers Specify This Model
- API 670 Compliant — Meets the industry standard for machinery protection systems without additional signal conditioning
- Direct 4–20 mA Output — Interfaces natively with DCS, PLC, and safety instrumented systems (SIS) without intermediate converters
- Proven Eddy-Current Technology — Non-contact measurement eliminates wear, ensuring >10-year service life in harsh environments
- Plug-Compatible with 3300 System — Drop-in replacement for existing Bently Nevada 3300 Series installations; no recalibration required
- Hazardous Area Rated — ATEX/IECEx certification supports deployment in Zone 1/Zone 2 classified areas
- Tight Linearity — ≤±0.5% full-scale linearity error ensures accurate trip-point discrimination
Complete System Bill of Materials
A fully functional Bently Nevada 3300 thrust monitoring channel typically requires:
- Proximity Probe — 3300 XL 25 mm (e.g., 330130-080-00-00)
- Extension Cable — 3300 Series, matched length (included in 991-25-50-02-05 kit)
- Thrust Transmitter — 991-25-50-02-05 (this item)
- Rack / Monitor — 3500/42M Position Monitor or equivalent 3300 rack card
- Power Supply — 24 VDC instrument-grade supply (e.g., 3500/15 Power Supply)
- Interconnect Cable — Shielded twisted-pair, 24 AWG, per ISA-S5.1
Contact Konmask for complete system quotations and compatibility verification.
Compliance & Industry Standards
- API 670 — Machinery Protection Systems (5th Edition)
- IEC 61511 — Functional Safety for SIS (SIL-capable installation)
- ATEX Directive 2014/34/EU — Equipment for explosive atmospheres
- IECEx Scheme — International certification for Ex equipment
- CE Marking — EU market conformity
- RoHS Compliant — Restriction of hazardous substances
Quality Assurance & Sourcing
Every 991-25-50-02-05 unit supplied by Konmask undergoes the following verification process:
- Visual & Dimensional Inspection — Label authenticity, connector integrity, and housing condition checked against OEM reference
- Functional Bench Test — Output signal and gap-voltage response verified prior to shipment
- Traceability Documentation — Serial number, test records, and certificate of conformance provided on request
- Secure Packaging — ESD-safe, foam-lined packaging with desiccant for international transit
We source from authorized distributors and verified industrial surplus channels. New, refurbished, and exchange units available — please specify condition requirement at inquiry.
How to Source This Part
Ready to order or need a formal quotation?
- Online: Add to cart directly at Konmask.com
- Email RFQ: support@konmask.com — include quantity, required delivery date, and condition preference
- Phone / WhatsApp: +0086 19859288691 (Mon–Fri, 09:00–18:00 CST)
- Lead Time: In-stock units ship within 1–3 business days; ex-works Xiamen, China
- Export: DHL / FedEx / UPS international express; EXW, FOB, CIF terms available
Application-Specific FAQ
Q: Is the 991-25-50-02-05 a direct replacement for the older 3300/20 thrust monitor?
A: Yes. The 991-series transmitter outputs a standard 4–20 mA signal compatible with any 3300-series rack or third-party monitor accepting loop-powered inputs. No probe recalibration is required if the same probe and extension cable are reused.
Q: Can this transmitter be used with non-Bently Nevada DCS systems (e.g., Emerson DeltaV, Honeywell Experion)?
A: Absolutely. The 4–20 mA output is universal. Simply configure the DCS AI card for the corresponding engineering unit range (typically ±25 mil or ±0.635 mm).
Q: What is the maximum cable run from probe tip to transmitter?
A: The 991-25-50-02-05 kit includes a 5.0 m extension cable. Total probe-to-transmitter distance must not exceed the calibrated range specified in the Bently Nevada system datasheet (typically 5 m or 9 m depending on probe model).
Q: Do you provide calibration certificates?
A: Yes. NIST-traceable calibration reports are available upon request for an additional fee. Please specify at time of order.
Q: Can Konmask supply the complete 3300 thrust monitoring loop?
A: Yes — we stock probes, extension cables, transmitters, rack cards, and power supplies. Contact us for a complete BOM quotation.
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Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
