The Bently Nevada 31000-28-05-00-061-01-02, also cataloged as the 31000 Proximity Probe Housing Assembly, operates as a dedicated hardware component for physical containment and external sensor adjustment within TSI (Turbine Supervisory Instrumentation) platforms.

Mechanical Option Code Configurations

This configuration breakdown specifies the exact physical dimensions, electrical ratings, and conduit fittings pre-assembled for this specific model code:

• 31000: Base model designation for the standard English Proximity Probe Housing Assembly (fully compliant with API 670 requirements).
• -28: Pre-installed probe selection: 3300 XL 8 mm proximity probe with multiple approvals.
• -05: Probe cable length of 0.5 m (20 inches).
• -00: No standoff adapter included.
• -061: Probe penetration option of 6.1 inches (154.94 mm).
• -01: Fittings configuration containing one 3/4-14 NPT fitting and two plugs.
• -02: Main housing-to-case mounting thread option of 3/4-14 NPT.

Housing & Electrical Hardware Parameters

Eddy-Current Probe Scaling and Rotor Dynamics Integration

The housing contains a pre-installed 3300 XL 8 mm eddy-current probe, designed to output a linear scale factor of 200 mV/mil (7.87 V/mm) when matching a calibrated 3300 XL Proximitor. The probe housing permits external gap voltage validation, typically targeted to achieve a -10 VDC baseline setting. By utilizing the physical sleeve design, engineers can adjust the probe gap externally without shutting down the machinery or exposing the interior bearing housing. This design isolates the probe from hazardous atmospheres and process lubricants, suppressing cross-talk and high-frequency interference across adjacent channels while providing continuous rotor dynamics and axial position data.

Package Bill of Materials

• 1 x Bently Nevada 31000-28-05-00-061-01-02 Housing Assembly
• 1 x Pre-installed 3300 XL 8 mm Proximity Probe (0.5 m cable)
• 1 x 3/4-14 NPT explosion-proof conduit fitting
• 2 x 3/4-14 NPT pipe plugs

Mechanical Installation and Sleeve Insertion Rules

• Machine Case Thread Mating

  Ensure the outer machine casing has a clean, tapped 3/4-14 NPT mounting hole. Apply high-temperature thread sealant (e.g., PTFE tape or liquid pipe compound) to the mounting threads, and torque the housing body to achieve standard NPT metal-to-metal interference engagement (minimum of 5 full threads engaged).

• Radial Alignment Verification

  When measuring dynamic radial vibration or Keyphasor pulses, ensure the assembly is rigidly affixed to the main bearing housing. Any relative movement between the housing and the bearing casing will introduce external structure-borne vibration, distorting the shaft displacement readings.

• Dynamic Probe Gap Adjustment

  To calibrate the physical gap without casing disassembly, loosen the internal compression gland. Slide the probe assembly axially while measuring the output voltage on the Proximitor loop until the -10 VDC baseline target is displayed, then retighten the gland.

• Conduit Routing and Seals

  Route the probe's unarmored 0.5 m cable out through the 3/4-14 NPT conduit fitting. Install a dedicated sealing conduit junction box immediately adjacent to the housing to prevent moisture ingress, process gas escape, or condensation from draining back into the terminal enclosure.

Transducer System Technical FAQ

• Can the internal probe be replaced without depressurizing or shutting down the machine?

  Yes. The physical sleeve design blocks oil splash, permitting sensor gap adjustment or complete probe replacement while the machine remains operational.

• What occurs if condensation pools inside the thermoplastic housing?

  Liquid buildup inside the PPS housing degrades the cable connector contact, shifting loop impedance and altering the 200 mV/mil scale factor.

• Are extra standoff adapters compatible with this specific model build?

  No. This assembly uses the -00 option code, meaning it has no standoff adapter, and must mount directly into a flush casing port.

• Why is polyphenylene sulfide (PPS) used for the main dome housing?

  PPS is an advanced thermoplastic that provides superior chemical resistance to corrosive refinery lubricants, synthetic fluids, and organic solvents.

• How do you suppress signal cross-talk when multiple housings are mounted close together?

  Ensure all housing enclosures and field conduits are connected to a common instrument ground, and route probe cables in separate shielded bundles.

• Does this assembly support non-destructive testing and field gap validation?

  Yes. Multimeter test pins can be connected to the Proximitor terminal block to read the gap voltage without removing the probe casing.

• What is the temperature limit for the internal 3300 XL probe and casing?

  Both the PPS housing outer shell and the internal 3300 XL 8 mm probe are rated for a continuous operating range of -51 to +177 deg C.

• Is it possible to install a 3300 XL 5 mm probe inside this 31000 housing sleeve?

  No. This sleeve is machined specifically for the 3300 XL 8 mm probe thread and tip configuration; other sizes will not lock in place safely.