Bently Nevada 24701-28-05-XX-028-04-XX MOD 323933-00-02 Proximity Probe Housing Assembly

Product Overview

The Bently Nevada 24701-28-05-XX-028-04-XX MOD 323933-00-02 is a specialized Proximity Probe Housing Assembly designed for internal mounting applications within the 3300 XL series vibration monitoring systems. This assembly facilitates the secure installation and environmental protection of an 8 mm proximity probe through the machine casing.

Constructed with a 303 stainless steel body and a 304 stainless steel sleeve, the housing is engineered to withstand high-pressure lubricants and corrosive atmospheres common in steam turbines, centrifugal compressors, and industrial gearboxes. This specific configuration includes a 3300 XL 8 mm probe with multiple hazardous area approvals, a 0.5-metre integral cable, and a 2.8-inch probe penetration depth. The "MOD" suffix indicates a custom factory modification (323933-00-02) tailored to specific OEM or end-user engineering requirements, ensuring precise alignment with machine internal clearances.

Hardware Configuration

Ordering Information

This assembly is configured according to Bently Nevada standard option codes. Procurement should verify all suffix segments to ensure mechanical compatibility.

Engineering & Installation Guide

Probe Penetration and Air Gap Setting:

The 2.8-inch penetration depth must be verified against the machine casing thickness and the required standoff from the shaft. Precise air gap adjustment is critical for the linear range of the 3300 XL system. Use a calibrated voltmeter to set the gap voltage (typically -10.0 Vdc for a mid-range gap) before final torquing.

Sealing and Pressure Integrity:

The 24701 housing is designed to maintain a seal against machine internal pressure. Ensure the NPT threads are treated with appropriate industrial-grade sealant (e.g., Loctite 567 or equivalent) to prevent oil leakage. Avoid over-torquing the probe within the sleeve, as this can damage the probe tip or the internal threading.

Cable Protection:

The 0.5-metre cable segment is susceptible to mechanical damage during installation. All internal wiring should be secured using stainless steel clips to prevent cable whip or fatigue caused by machine vibration. Use flexible conduit for the external portion of the cable run to the Proximitor Sensor.

Replacement Precautions:

When replacing an existing housing, ensure the MOD 323933-00-02 specification matches the original installation. Standard 24701 units may lack the specific internal clearances or thread modifications present in this MOD version, potentially leading to mechanical interference or seal failure.

Troubleshooting FAQ

Q: Can a standard 3300 XL probe be used as a replacement within this housing?

A: While the housing accepts 8 mm probes, the specific probe in this assembly (-28 option) includes multiple approvals and a specialized connector. Always match the probe part number found on the cable tag to ensure electrical compatibility with the Proximitor.

Q: How do I identify the specific modification in MOD 323933-00-02?

A: MOD numbers are internal factory records. This modification typically involves non-standard sleeve lengths, specialized thread pitches, or unique material treatments. Refer to your original machine OEM manual or Bently Nevada data sheet for this MOD code.

Q: What is the significance of the 3/4-14 NPT plug?

A: Option -04 provides one plug for unused conduit entries in the housing head. Ensure this is installed and tightened to maintain the IP/NEMA rating of the assembly.

Q: Is this housing suitable for high-temperature service?

A: The stainless steel construction is rated for high temperatures, but the limit is governed by the 3300 XL probe's specifications. Generally, the probe is rated up to 177°C (350°F).