Technical Specifications Breakdown
Key parameters for the 21128-14-03 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Material | 303 Stainless Steel |
| Mounting Thread & Cap Option | 14 = 1/2-in 14 BSP (G 1/2-in) with tall cap |
| Cable Exit Fitting Option | 03 = 1/2-in NPT, explosion-proof and cable grip fittings |
| Temperature Rating | -29°C to +121°C (-20 °F to +250°F) |
| Moisture Resistance | Resistant to moisture and corrosion but is not submersible |
| O-ring Material | Neoprene |
| Weight | 1.6 kg (3.55 lb) |
| Outlet Port Size | 1/2-in NPT |
| Internal Mounting Thread (21128 and CA21128) | 1/2-in 20 UNF |
Application Scenarios That Reduce Total Cost of Ownership
Hose-Directed Washdown Areas
In food processing or chemical plants where high-pressure water cleaning is routine, the 21128-14-03 housing prevents water ingress that would otherwise damage velocity sensors. This avoids frequent sensor replacements and production downtime.
Corrosive Atmosphere Installations
Coastal refineries and offshore platforms expose equipment to salt spray. The 303 stainless steel construction resists corrosion, maintaining housing integrity over years of service.
Physical Abuse Protection
In mining or heavy manufacturing, sensors near moving machinery risk impact damage. The housing absorbs mechanical shocks, preserving sensor calibration and avoiding recalibration costs.

Installation Guidance for Maximum ROI
Proper installation is critical to achieving the NEMA 4X and IP65 ratings. Ensure the housing is mounted with the 1/2-in 14 BSP thread (tall cap) and the 1/2-in NPT cable exit fitting is tightened to manufacturer torque specifications. When using the 21128 Housing, cable part number 89477-AA is necessary to connect the Velomitor Sensor to a monitor. Verify the O-ring (neoprene) is seated correctly to maintain the moisture seal. Avoid submerging the assembly, as the housing is not submersible.
Maintenance and Reliability
Inspect the neoprene O-ring annually for cracks or compression set. Replace if degraded to maintain IP65 integrity. Clean the housing exterior with mild detergent to prevent buildup of corrosive residues. No internal maintenance is required; the housing is a passive protective enclosure.
Cost-Effective Protection for Velocity Sensors
Industrial environments expose velocity sensors to water, corrosion, and physical impact. The Bently Nevada 21128-14-03 velocity transducer housing provides a robust, cost-efficient solution that extends sensor life and reduces unplanned replacement expenses. Constructed from 303 stainless steel, this housing meets NEMA 4X and IP65 requirements when properly installed, ensuring reliable operation in harsh conditions without the premium cost of explosion-proof enclosures.

Selection Guide and Purchasing Advice
For non-hazardous environments, the 21128-14-03 offers the best balance of protection and cost. If explosion-proof certification is needed, consider the CA21128 version with CSA approval. For BASEEFA-approved installations, the BA42608 housing is required. The tall cap option is mandatory when installing a Velomitor CT or a 9200/74712 Seismoprobe with isolated base. Contact AutoDCSTech to verify current lifecycle status and availability before ordering.
Troubleshooting Common Issues
If moisture is found inside the housing, inspect the O-ring and cable entry fitting for damage. Ensure the 1/2-in NPT fitting is properly sealed with thread sealant. If the housing shows physical damage, replace it immediately to restore sensor protection.
Availability & Condition at AutoDCSTech
| Part Number | 21128-14-03 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
