21000-16-05-00-203-03-02 | Bently Nevada | Proximity Probe Housing Assemblies

Product Overview

The 21000-16-05-00-203-03-02 (21000-16-05-00-203-03-02) is a heavy-duty Proximity Probe Housing Assembly designed by Bently Nevada to provide superior environmental protection for displacement sensors. This assembly is critical for Turbine Supervisory Instrumentation (TSI) applications in harsh industrial environments such as petrochemical refineries, natural gas processing plants, and hydro-electric facilities. By encasing the 3300 XL 8 mm probe within a ruggedized aluminum and stainless steel structure, it facilitates external probe adjustment and replacement without dismantling the machine casing. This "external access" capability is a vital factor in reducing mean time to repair (MTTR) and minimizing expensive production downtime during sensor maintenance or calibration cycles in high-criticality rotating machinery.

Suffix Breakdown

The model code 21000-16-05-00-203-03-02 specifies the following mechanical and electrical configuration:

• 16: Probe Option with connector - Includes a 3300 XL 8 mm proximity probe.

• 05: Probe Cable Length - 0.5 meter (20 inches).

• 00: Standoff Adapter - No standoff adapter supplied.

• 203: Probe Penetration - 20.3 inches total penetration depth.

• 03: Fittings Option - Includes one 3/4-14 NPT plug, one 3/4-14 to 1/2-14 NPT reducer, and one cable seal grip with multiple grommet sizes for versatile cable management.

• 02: Mounting Thread Option - 3/4-14 NPT mounting threads.

Technical Specifications

Technical FAQs

Can this housing be used for radial vibration or axial thrust measurements?

Yes, the 21000 series housing is suitable for both radial and axial measurements. However, the penetration depth must be precisely calculated to ensure the probe tip reaches the target surface within its linear range while remaining protected by the sleeve.

How does this housing handle hazardous area requirements?

The housing itself is a mechanical enclosure. While it provides physical protection, the overall explosion-proof or flame-proof rating depends on the probe and Proximitor sensor used, as well as the seal integrity of the NPT fittings and cable grips provided in the 03 option.

What is the benefit of the aluminum body and stainless steel sleeve combination?

The aluminum body provides a lightweight, corrosion-resistant exterior for the main housing, while the 304 stainless steel sleeve ensures structural rigidity and protection for the probe lead where it penetrates the machine casing and faces potential oil or chemical exposure.

Engineering & Installation Guide

• Seal Integrity: When installing the 3/4-14 NPT mounting threads, use a high-quality thread sealant to prevent oil leakage from the machine casing. Do not rely solely on the mechanical fit of the threads for pressure containment.

• Probe Gapping: Before final assembly, verify the gap between the probe tip and the target shaft. Connect the probe to a Proximitor sensor and monitor the DC voltage. For a standard 3300 XL 8 mm probe, the gap should be set to -10.0 VDC (center of the linear range) to allow for both positive and negative displacement measurement.

• Cable Routing: Use the provided cable seal grip (Option 03) to ensure the probe lead is not pinched or subjected to excessive tension. Ensure the grommet size matches your cable diameter exactly to maintain the environmental IP rating of the housing.

• Penetration Verification: Always double-check the 20.3-inch penetration depth against the machine drawings. If the probe is too short, it will not reach the target; if too long, the sleeve or probe tip may strike the rotating shaft, causing immediate mechanical damage.