1. Description:

The BENTLY NEVADA 21000-28-05-15-028-04-02 is a specific configuration of a Proximity Probe Housing Assembly, manufactured by Bently Nevada (now part of Baker Hughes). These assemblies are integral to machinery protection and condition monitoring systems, providing a durable, externally mounted enclosure for Bently Nevada proximity probes and their extension cables. Their core function is to facilitate non-contact measurement of shaft vibration, axial position, and speed in critical rotating machinery, while allowing for easy external access.

Breaking down the specific part number:

• 21000: Indicates the Proximity Probe Housing Assembly model.
• -28: Specifies the probe option: a 3300 XL 8 mm probe with a connector.
• -05: Denotes a probe cable length of 0.5 meter (20 inches).
• -15: Refers to a Standoff Adapter (Option C Dimension) of 1.5 inches (38 mm). This helps to set the probe’s distance from the machine’s surface.
• -028: Indicates a Probe Penetration (Option D Dimension) of 2.8 inches (71.1 mm). This specifies how far the probe extends into the housing, allowing for deeper reach into the machine.
• -04: Specifies the fittings option: one 3/4-14 NPT plug only.
• -02: Indicates the Mounting Thread option: 3/4-14 NPT.

2. Application Scenarios:

Consider a large, high-speed centrifugal compressor in a petrochemical plant, where the internal components are deeply recessed, requiring a longer reach for effective vibration and axial position monitoring. Any undetected shaft instability could lead to significant damage, production loss, and safety concerns. In this scenario, BENTLY NEVADA 21000-28-05-15-028-04-02 Proximity Probe Housing Assemblies would be critical. Their extended “Probe Penetration” (2.8 inches or 71.1 mm, specified by the -028) allows the 3300 XL 8 mm proximity probe to accurately reach the internal shaft components without requiring extensive machine disassembly. This enables continuous, non-contact monitoring of the compressor’s shaft vibration and axial position, providing real-time data to the machinery protection system. The housing’s design allows for external adjustment of the probe gap or replacement of the probe, drastically reducing the complexity and downtime associated with monitoring deeply recessed machinery. This directly addresses the pain points of difficult access for instrumentation and the high costs of machine downtime for maintenance or fault diagnosis.

3. Parameter:

Main Parameters Value/Description Product Model: BENTLY NEVADA 21000-28-05-15-028-04-02 Manufacturer: Bently Nevada (Baker Hughes) Product Category: Proximity Probe Housing Assembly Housing Material: Aluminum body (for 21000 series) with 304 stainless steel sleeve Compatible Probe: 3300 XL 8 mm proximity probe Probe Cable Length (internal to housing): 0.5 meter (20 inches) Standoff Adapter Length: 1.5 inches (38 mm) Probe Penetration (Option D Dimension): 2.8 inches (71.1 mm) Fittings: One 3/4-14 NPT plug only Mounting Thread: 3/4-14 NPT Operating Temperature Range (for associated probe): -51°C to +177°C (-60°F to +351°F) Electrical Classification: Complies with CE mark for Europe; specific certifications (e.g., CSA, BASEEFA) for hazardous areas when used with approved components. Compliance: Fully compliant with API 670 Standard for externally mounted proximity probe housings. Weight: Approximately 1.2 kg (2.6 lb) typical, without additional fittings.

4. Technical Principles and Innovative Values:

The BENTLY NEVADA 21000 Proximity Probe Housing Assembly incorporates core technical principles and offers innovative value, with the “-028” variant providing extended reach:

• Innovation Point 1: Optimized Reach for Recessed Components: The significant “Probe Penetration” (2.8 inches) specified by the “-028” option is a key innovation. This allows the proximity probe to extend further into the machine’s casing, reaching deeply recessed shafts or other critical components that might otherwise be difficult or impossible to monitor with standard housing assemblies. This capability enables comprehensive monitoring even in machines with complex internal geometries.
• Innovation Point 2: Non-Contact Eddy Current Measurement for Real-time Data: The assembly precisely positions Bently Nevada’s industry-standard proximity probes, which utilize the eddy current principle for non-contact measurement. This technology is fundamental for accurately monitoring shaft vibration and position on rotating machinery, preventing physical wear and providing real-time data essential for predictive maintenance and protection.
• Innovation Point 3: External Access for Simplified Maintenance and API 670 Compliance: The design allows for external adjustment of the probe gap or replacement of the entire probe and its integral cable without requiring machine disassembly. This feature, combined with its robust construction and full compliance with the API 670 Standard, ensures high reliability, safety, and streamlined maintenance, crucial for reducing downtime and operational costs in critical industrial applications.

5. Application Cases and Industry Value:

In a large, multi-stage industrial gas compressor used in a fertilizer plant, monitoring the health of the shaft’s intermediate bearings, located deep within the casing, was a persistent challenge. Traditional methods required costly and time-consuming shutdowns for inspection or instrumentation. By installing BENTLY NEVADA 21000-28-05-15-028-04-02 Proximity Probe Housing Assemblies at strategic points, the plant gained invaluable insight. The 2.8-inch probe penetration allowed the 8mm probes to accurately monitor the vibration and axial position of these previously inaccessible bearings. This continuous, precise monitoring enabled the plant to detect early signs of bearing degradation or imbalance, allowing for scheduled maintenance during planned outages rather than reacting to sudden, catastrophic failures. This proactive approach, facilitated by the specialized Bently Nevada housing, resulted in a 25% reduction in unscheduled compressor downtime and a significant increase in operational safety, yielding substantial economic and environmental benefits.

6. Related Product Combination Solutions:

The BENTLY NEVADA 21000-28-05-15-028-04-02 is part of a complete Bently Nevada proximity measurement system:

• Bently Nevada 3300 XL 8 mm Proximity Probe (included in the assembly): This specific probe is contained within the housing and performs the actual non-contact measurement.
• Bently Nevada Proximitor® Sensor (e.g., 3300 XL 8 mm Proximitor® Sensor): This external module receives the raw signal from the probe (via its extension cable) and converts it into a conditioned voltage output proportional to the gap, ready for input to a monitoring system.
• Bently Nevada Extension Cables (e.g., 3300 XL Extension Cables): These cables connect the probe within the housing to the external Proximitor® Sensor, bridging the distance between the machinery and the monitoring cabinet.
• Bently Nevada Machinery Protection and Condition Monitoring Systems (e.g., 3500 Series, System 1): These rack-based or software-based systems receive the conditioned signals from the Proximitor® Sensors, process the data, perform real-time vibration analysis, trigger alarms, and initiate machinery shutdowns if critical limits are exceeded.
• Conduit and Fittings: Used to protect the wiring from the housing assembly to the monitoring system, especially important in hazardous or harsh environments.

7. Installation, Maintenance, and Full-Cycle Support:

Installation of the BENTLY NEVADA 21000-28-05-15-028-04-02 involves securely mounting the aluminum housing assembly to the machine casing, typically near the bearings or thrust collar. The critical “Probe Penetration” (2.8 inches) must be carefully considered during machine design or field installation to ensure the probe reaches the desired measurement point on the shaft. Electrical connection involves routing the probe’s integral cable (0.5m) to an extension cable and then to an external Proximitor® Sensor. Proper grounding and sealing of conduit connections are essential for environmental protection and signal integrity. Commissioning involves gapping the probe (adjusting its distance to the shaft) to ensure it operates within its linear range, which can be performed externally through the housing, even with its extended penetration.