21128-03-03 | Bently Nevada -29°C to +121°C Velocity Transducer Housing

Introduction to the Bently Nevada 21128-03-03 Velocity Transducer Housing

When harsh environmental conditions threaten the reliability of vibration monitoring, the 21128-03-03 from Bently Nevada delivers robust protection. This velocity transducer housing is engineered to shield sensors from hose-directed water, corrosion, physical abuse, and other adverse conditions. Constructed from 303 stainless steel, the 21128-03-03 meets NEMA 4X and IP65 requirements when properly installed, making it a preferred choice for non-hazardous locations.

Key Features and Technical Specifications

• Temperature Rating: -29°C to +121°C (-20°F to +250°F)
• Moisture Resistance: Resistant to moisture and corrosion but not submersible
• O-ring Material: Neoprene
• Weight: 1.6 kg (3.55 lb) without sensor or fittings
• Mounting Thread: 1/2-in 20 UNF
• Cable Exit: 1/2-in NPT with explosion-proof and cable grip fittings
• Outlet Port Size: 1/2-in NPT

A distinctive feature of the 21128-03-03 is its wide temperature range, enabling reliable operation from freezing cold to high-heat environments, which is critical for outdoor or process-adjacent installations.

Applications and Use Cases

The 21128-03-03 is ideal for protecting velocity sensors in industries such as oil and gas, power generation, and manufacturing. Its corrosion-resistant design suits washdown areas and outdoor installations. For example, in a refinery cooling tower, the housing prevents moisture ingress and physical damage, ensuring continuous vibration monitoring.

Installation and Setup

Install the 21128-03-03 using the 1/2-in 20 UNF internal mounting thread. Secure the housing with the provided 1/2-in NPT cable exit fittings. Ensure proper sealing of the O-ring to maintain IP65 protection. For Velomitor CT sensors, order the tall cap option. When using the 21128 housing, cable part number 89477-AA is necessary to connect the Velomitor sensor to a monitor.

Maintenance and Reliability

Regularly inspect the neoprene O-ring and housing seals for wear or damage. The stainless steel construction resists corrosion, but periodic cleaning with a damp cloth helps maintain performance. Verify that cable fittings remain tight to preserve the IP65 rating. Following these steps extends service life and reduces replacement costs.

Compatibility and Integration

The 21128-03-03 is designed for use with Bently Nevada velocity sensors such as the Velomitor CT, 9200, and 74712 Seismoprobe. For explosion-proof installations, order the CA21128 version with a CSA-approved sensor. The BA42608 housing is available for BASEEFA-approved installations requiring BS EN 60079 14 compliance.

Frequently Asked Questions About the 21128-03-03

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

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

Q: Is the 21128-03-03 submersible?

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

Q: What material is the O-ring made of?

A: The O-ring material is neoprene.

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

A: The weight is 1.6 kg (3.55 lb) without velocity sensor or fittings.

Q: What cable is needed for the Velomitor sensor?

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

Product Support and Availability

The 21128-03-03 is available from Petro Auto Tech. Please verify current lifecycle status and availability with Petro Auto Tech before ordering. In stock and ready to ship.