Product Overview
The Bently Nevada 21000-28-00-20-018-04-02 is a precision-engineered proximity probe housing assembly designed for reliable vibration monitoring in critical rotating machinery. This unit combines a rugged aluminum body with a 304 stainless steel sleeve, ensuring durability in demanding industrial environments. It is part of the trusted 21000 series and is fully compliant with the American Petroleum Institute's (API) 670 Standard for externally mounted proximity probe housings. With its selectable hazardous area approvals and CSA Type 4 enclosure rating, this assembly delivers dependable performance in both standard and intrinsically safe applications.
Key Specifications
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Probe: 3300 XL 8 mm probe with connector (selectable hazardous area approvals)
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Probe Cable Length: Not required (option B = 00)
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Standoff Adapter Length: 2 inches (option C = 20)
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Probe Penetration: 1.8 inches (option D = -018)
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Fittings Option: One 3/4-14 NPT plug only (option E = 04)
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Mounting Thread: 3/4-14 NPT (option F = -02)
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Material: Aluminum body with 304 stainless steel sleeve
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Weight: 1.1 kg (2.4 lb) typical, without fittings
Technical Specifications
| Parameter |
Value |
| Model |
21000 Proximity Probe Housing Assemblies |
| Probe Type |
3300 XL 8 mm probe with connector |
| Standoff Adapter Length |
2 in |
| Probe Penetration |
1.8 in |
| Fittings |
One 3/4-14 NPT plug only |
| Mounting Thread |
3/4-14 NPT |
| Material |
Aluminum body with 304 stainless steel sleeve |
| Weight |
1.1 kg (2.4 lb) typical, without fittings |
| Certifications |
CSA Type 4 enclosure, explosion proof for hazardous areas |
| Standards |
API 670 compliant |
Applications
The 21000-28-00-20-018-04-02 is ideal for monitoring shaft vibration in turbines, compressors, pumps, and other rotating equipment. Its 3300 XL 8 mm probe delivers accurate displacement measurements, while the rugged housing protects the sensor in harsh conditions. With its CSA Type 4 rating and explosion-proof design, this assembly suits hazardous areas where safety is paramount. Whether used in oil and gas, power generation, or petrochemical plants, this housing ensures reliable performance and minimal downtime.
Installation & Setup
Proper installation is critical for accurate readings. The mounting thread of 3/4-14 NPT must match the machine's tapped hole. For probe penetration lengths between 1.0 and 2.0 inches, counter boring the machine case may be necessary to reduce side or rear view effects. If the total penetration (C plus D) exceeds 300 mm (12 in), add sleeve support near the probe to prevent resonance. The adjustment range for option D is 13 mm (±0.5 in). Always follow the manufacturer's guidelines for torque and alignment.
Maintenance & Reliability
Regular inspection of the housing and probe is recommended to ensure long-term reliability. Check the O-rings and thread seal for wear, and verify that the dome cover is securely tightened. The stainless steel sleeve resists corrosion, and the aluminum body is lightweight yet robust. With proper care, this assembly provides years of trouble-free service, reducing unplanned maintenance costs.
Selection Guide
When ordering, verify the suffix codes to match your application. The 21000-28-00-20-018-04-02 includes a 3300 XL 8 mm probe, 2-inch standoff adapter, and 1.8-inch probe penetration. Ensure the mounting thread option is selected when the standoff adapter length is not -00. For hazardous area requirements, confirm the probe's approval rating. PLC Source PRO offers this new, original unit with a 12-month factory warranty, ensuring you receive a genuine, reliable component.