Product Overview
When machine vibration threatens uptime, the Bently Nevada 21000-28-05-00-028-04-02 provides a robust, externally mounted housing for proximity probes. This Industrial Automation Module is engineered to protect the sensor in harsh environments while maintaining precise measurement. Part of the 21000 series, the 21000-28-05-00-028-04-02 is designed for permanent installation on rotating machinery such as compressors, turbines, and pumps.
Key Features & Construction
-
Aluminum body with 304 stainless steel sleeve – durable and corrosion-resistant.
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CSA Type 4 enclosure – rated explosion proof for hazardous areas.
-
API 670 compliant – meets American Petroleum Institute standards for externally mounted proximity probe housings.
- Includes dome cover, threaded ports, probe sleeve, O-rings, reverse mount probe, thread seal, and optional conduit fittings.
Technical Specifications
| Specification |
Value |
| Model |
21000-28-05-00-028-04-02 |
| Probe with Connector |
28 – 3300 XL 8 mm probe, selectable hazardous area approvals |
| Probe Cable Length |
05 – 0.5 m (20 in) |
| Standoff Adapter Length |
00 – No standoff adapter |
| Probe Penetration (Option D) |
-028 – 2.8 in |
| Fittings Option |
04 – One 3/4-14 NPT plug only |
| Mounting Thread Option |
-02 – 3/4-14 NPT (required when no standoff adapter) |
| Maximum (C)+(D) Dimension |
13.5 in (34.3 cm) |
| Weight |
1.1 kg (2.4 lb) typical, without fittings |
Applications & Use Cases
The 21000-28-05-00-028-04-02 is ideal for vibration monitoring on critical rotating equipment. In a refinery, this housing protects the probe from explosive atmospheres while delivering reliable shaft displacement readings. For a power generation turbine, the 2.8-inch penetration allows precise placement near the bearing, and the 0.5-meter cable simplifies routing to the monitor. The CSA Type 4 rating ensures the assembly withstands dust, oil, and water spray, making it suitable for harsh industrial environments.
Installation & Setup Guidance
When installing the 21000-28-05-00-028-04-02, ensure the mounting thread (3/4-14 NPT) matches the machine case. For probe penetration lengths between 1.0 and 2.0 inches, counter boring the machine case may be necessary to reduce side view or rear view effects. If the combined probe 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), allowing fine positioning. Always verify the probe tip gap according to the system manual.
Maintenance & Reliability
Regularly inspect the housing for loose fittings or signs of corrosion. The aluminum and stainless steel construction resists wear, but check O-rings and seals during scheduled outages. Because the unit is explosion-proof, never open the housing while power is applied in a hazardous area. Following a simple inspection routine extends service life and prevents unplanned downtime—key to maximizing ROI.
Selection Guide & Purchasing Advice
Before purchasing, verify your required probe penetration (C plus D) and mounting thread. The 21000-28-05-00-028-04-02 includes a 3/4-14 NPT plug and requires the -02 mounting thread option. Confirm that your proximity probe is compatible with the 8 mm 3300 XL series. For reliable sourcing, PLC Source PRO offers this genuine Bently Nevada module in new, factory-sealed condition with a 12-month warranty.