Product Overview

The Bently Nevada 21000-28-05-00-75-01-02 is a high-integrity Proximity Probe Housing designed to protect critical vibration sensors in the most demanding industrial environments. This aluminum assembly provides a ruggedized enclosure for 3300 XL 8mm proximity probes, facilitating external mounting and easy gapping without requiring machine disassembly. It serves as a vital component in Turbine Supervisory Instrumentation (TSI), ensuring that radial vibration and axial position data remain uncompromised by external mechanical stress or environmental contaminants. By utilizing this housing, engineering teams achieve superior protection for sensors on steam turbines, compressors, and large pumps, maintaining the stability of signals fed into the Bently Nevada 3500 monitoring system and integrated DCS platforms.

Housing Configuration Matrix

Suffix Breakdown and Physical Geometry

The alphanumeric code 21000-28-05-00-75-01-02 dictates the mechanical dimensions and approval ratings for this transducer assembly:

Unthreaded Length (28): 2.8-inch unthreaded section, allowing the housing to pass through machine insulation or thick outer casings.

Overall Case Length (05): 0.5-inch threaded section, used for securing the housing into the machine's bearing cap or bracket.

Standoff Distance (00): No standoff required, facilitating a direct flush-mount profile for space-constrained installations.

Probe Thread (75): 3/4-14 NPT thread configuration, standard for heavy-duty industrial conduit and sensor interfaces.

Fittings Option (01): Includes one 3/4-14 NPT plug and specialized washers for sealing the unit against oil and moisture ingress.

Agency Approval (02): Multiple Approvals including ATEX, IECEx, and North American hazardous area certifications, ensuring compliance in Zone 0 and Division 1 locations.

Performance and Physical Specifications

Field Commissioning Protocol

Successful installation requires the precise alignment of the internal proximity probe before sealing the housing. Technicians must set the static gap voltage—typically to -10.0 VDC—by adjusting the probe's position within the housing sleeve using a digital voltmeter (DVM). Maintain a minimum cable bend radius of 25.4 mm for the internal coaxial cable to prevent signal attenuation. Ensure the NPT threads are treated with an appropriate anti-seize compound or Teflon tape to prevent galling while maintaining the explosion-proof integrity of the assembly. For hazardous area deployments, verify the (02) approval plate matches the local zone classification.

Structural Integrity and System Integration

This housing excels in mitigating the effects of "oil soak" and physical impacts that often plague unprotected sensors. The aluminum construction provides excellent thermal dissipation and EMI shielding, protecting the micro-volt signals from industrial noise interference. It integrates seamlessly with the Bently Nevada 3500/42M monitor and Honeywell Experion PKS systems, providing the mechanical stability required for System 1 diagnostic software to generate accurate orbit and time-base plots. Its ruggedized design ensures that even in high-vibration or corrosive petrochemical environments, the transducer remains "OK," preventing false trips and ensuring reliable machinery protection.

Ordering info

• Bently Nevada 21000 series Aluminum Housing body

• Internal probe mounting sleeve and hardware

• 3/4-14 NPT sealing plug and O-rings

• Explosion-proof certification nameplate

• Individualized factory inspection documentation

Logistics and Protective Fulfillment

Delivery time: 2-7 days when payment finish. All orders ship globally via DHL, FEDEX, or UPS. We implement a multi-stage quality control process, including the use of anti-static industrial packaging and vacuum-sealed moisture barriers. Every housing assembly is secured with high-density shock-absorbent dunnage, ensuring the precision-machined threads and internal surfaces arrive in factory-sealed condition, ready for critical path installation.

Technical Support FAQ

Q1: Can I install this housing while the machine is running?

A1: Yes, one of the primary advantages of the 21000 series is that it allows for probe replacement or adjustment from the outside of the machine, provided the probe sleeve design allows for the gapping process while the shaft is in motion.

Q2: Why choose Aluminum over Stainless Steel?

A2: Aluminum offers a lighter weight and superior heat dissipation. While stainless steel is better for highly acidic environments, the A360 aluminum used here is specifically treated for excellent corrosion resistance in standard oil and gas applications.

Q3: Does this housing include the proximity probe?

A3: No, the 21000-28-05-00-75-01-02 is the housing assembly. The 3300 XL proximity probe and extension cable must be ordered separately to match your specific system length (5m or 9m).

Q4: How do I ensure a leak-proof seal with the NPT threads?

A4: Use a high-quality thread sealant approved for the operating temperature and chemical environment. Ensure the fittings are torqued to the manufacturer’s specifications to maintain the IP66 environmental rating.