21128-13-03 | Bently Nevada 1/2-in NPT Velocity Transducer Housing

Introduction to the 21128-13-03 Velocity Transducer Housing

When harsh environmental conditions threaten sensor reliability, the 21128-13-03 from Bently Nevada delivers robust protection. This velocity transducer housing is constructed from 303 stainless steel and designed to meet NEMA 4X and IP65 requirements when properly installed. By shielding velocity sensors from hose-directed water, corrosion, and physical abuse, this housing helps reduce unplanned downtime and replacement costs.

Key Features and Technical Specifications

• The 21128-13-03 features a 1/2-in 14 NPT mounting thread with a tall cap option for Velomitor CT sensors.
• Its cable exit fitting is 1/2-in NPT, explosion-proof, and includes cable grip fittings for secure installations.
• Temperature rating spans -29°C to +121°C (-20°F to +250°F), ensuring reliable performance in extreme conditions.
• Moisture resistance protects against corrosion but the unit is not submersible, avoiding false submersion claims.
• Neoprene O-ring material provides a durable seal against environmental ingress.
• Weight is 1.6 kg (3.55 lb) without sensor or fittings, making it lightweight for easy handling.

Real-World Applications and Cost Benefits

In petrochemical plants and offshore platforms, the 21128-13-03 prevents sensor damage from washdowns and corrosive atmospheres. By extending sensor life, this housing reduces replacement frequency and maintenance labor costs. The stainless steel construction also eliminates the need for frequent repainting or coating, further lowering total cost of ownership.

Installation and Setup Guidance

Mount the 21128-13-03 using the 1/2-in 20 UNF internal mounting thread. Ensure the cable part number 89477-AA is used to connect the Velomitor sensor to the monitor. For explosion-proof installations, verify that the cable exit fitting is properly torqued to maintain the IP65 rating.

Maintenance and Reliability Insights

Inspect the neoprene O-ring annually for cracks or wear to maintain the moisture seal. Clean the exterior with mild detergent and water; avoid abrasive tools that could damage the stainless steel surface. Regular checks help avoid costly sensor failures and unplanned production stops.

Compatibility and Integration

The 21128-13-03 is designed for use with Bently Nevada velocity sensors such as the Velomitor CT, 9200, and 74712 Seismoprobe with isolated base. The tall cap option is required for these sensors. For non-hazardous areas, the standard 21128 housing is preferred; for hazardous locations, order the CA21128 version with a CSA-approved sensor.

Frequently Asked Questions

Q: What is the temperature rating of the 21128-13-03?

A: The temperature rating is -29°C to +121°C (-20°F to +250°F).

Q: Is the 21128-13-03 submersible?

A: No, it is resistant to moisture and corrosion but is not submersible.

Q: What cable is needed for the Velomitor sensor with this housing?

A: Cable part number 89477-AA is necessary to connect the Velomitor sensor to a monitor.

Q: What is the weight of the 21128-13-03?

A: It weighs 1.6 kg (3.55 lb) without the velocity sensor or fittings.

Product Support and Availability

The 21128-13-03 is in stock and ready to ship. Contact Petro Auto Tech for current pricing and lead times. Please verify lifecycle status before ordering.