Bently Nevada 31000-28-05-00-037-03-02 3300 XL 8 mm Proximity Probe Housing Assembly

Product Overview

The 31000-28-05-00-037-03-02 is a ruggedized Proximity Probe Housing Assembly designed for external mounting of 3300 XL 8 mm transducers. This assembly is a critical infrastructure component in refineries, thermal power plants, and mining operations, where it facilitates radial vibration or Keyphasor measurements without requiring machine disassembly. By allowing external access for gap adjustment and probe replacement, the 31000 series significantly minimizes MTTR (Mean Time To Repair) and operational downtime. Constructed from high-strength, glass-reinforced Polyphenylene Sulfide (PPS) and stainless steel, this housing is fully compliant with API 670 standards, providing an explosion-proof and corrosion-resistant barrier for proximity probes in the most hazardous and demanding industrial environments.

Suffix Breakdown

The configuration string 31000-28-05-00-037-03-02 defines the precise mechanical and electrical interface of the housing:

• 28 (Probe with Connector): Includes a 3300 XL 8 mm probe with multiple international approvals.

• 05 (Probe Cable Length): Equipped with a 0.5 meter (20 inch) probe cable.

• 00 (Standoff Adapter Length): No standoff adapter is utilized for this configuration.

• 037 (Probe Penetration Option): Specifies a "D" dimension of 3.7 inches (94 mm) for probe depth into the machine casing.

• 03 (Fittings): Includes a comprehensive fitting kit: two plugs, one 3/4-14 NPT fitting, one SST reducer (3/4-14 to 1/2-14 NPT), and a cable seal grip with multiple grommets.

• 02 (Mounting Thread Option): Utilizes a 3/4-14 NPT mounting thread.

Technical Specifications

Field Engineering FAQs

Can this housing be used for axial thrust position measurements?

While the 31000 is the standard for radial vibration, Bently Nevada recommends the 21022 housing for dual proximity probe axial position measurements to ensure proper alignment and redundancy required for thrust safety.

How does the PPS material perform in chemically aggressive environments?

Polyphenylene Sulfide (PPS) is an advanced thermoplastic known for exceptional corrosion resistance. It withstands most industrial chemicals, though users should monitor pH levels as extreme values can erode the probe tip over time, potentially compromising the pressure seal.

Is the housing designed to hold internal machine pressure?

The 31000 is certified for NEMA 4X (hose-directed water) and IP66, but it is not a pressure-rated vessel. It seals differential pressure between the probe tip and housing body via Viton and Neoprene O-rings, but it is not designed to resist high internal machine pressures.

Engineering Installation and Maintenance Guidelines

• Mechanical Resonance Prevention: For total sleeve lengths ("C" plus "D" dimensions) exceeding 12 inches (305 mm), additional sleeve support must be installed near the probe tip. Failure to provide this support can lead to mechanical resonance, causing signal noise or fatigue failure of the sleeve.

• Torque Requirements: During installation, the retaining nut must be torqued to exactly 29.4 N-m (260 in-lb). Proper torque ensures environmental sealing and prevents the probe from backing out due to machine vibration.

• Static Dissipation in Hazardous Areas: The PPS housing material is designed for electrostatic dissipation in compliance with EN50014. Always ensure the grounding liner is installed and that the housing is properly bonded to the machine earth to prevent the buildup of static charges in explosive atmospheres.

• O-Ring Inspection: During any probe adjustment, inspect the Neoprene O-ring between the sleeve and the housing. If the O-ring shows signs of compression set or chemical degradation, it must be replaced to maintain the IP66 environmental rating.