21128-01-02 | Bently Nevada 1/2-in NPT Velocity Transducer Housing

What Is the Bently Nevada 21128-01-02?

When harsh conditions threaten sensor reliability, the 21128-01-02 from Bently Nevada delivers robust protection. This velocity transducer housing shields sensors from hose-directed water, corrosion, physical abuse, and other adverse environmental factors. Constructed from 303 stainless steel, it meets NEMA 4X and IP65 requirements when properly installed. The housing is preferred for most non-hazardous environments and features a 1/2-in NPT explosion-proof cable exit fitting.

Key Features & Technical Specs

• Temperature Rating: -29°C to +121°C (-20°F to +250°F), suitable for extreme thermal conditions.
• Moisture Resistance: Resists moisture and corrosion but is not submersible.
• O-ring Material: Neoprene ensures a reliable seal against contaminants.
• Weight: 1.6 kg (3.55 lb) without sensor or fittings, offering a sturdy yet manageable design.
• Mounting Thread: Unthreaded base with 28.5 mm diameter.
• Outlet Port: 1/2-in NPT for secure cable entry.

A distinctive feature is the 1/2-in NPT explosion-proof fitting, which provides an extra layer of safety in environments where flammable gases or dusts may be present.

Applications & Use Cases

This housing is ideal for rotating machinery monitoring in oil and gas, power generation, and heavy manufacturing. For example, in a refinery where water spray and corrosive chemicals are common, the 21128-01-02 ensures the velocity sensor remains operational. It also suits outdoor installations exposed to rain and temperature swings. By preventing damage, it reduces unplanned downtime and extends sensor life.

Installation Guide

Mount the housing on a flat surface using the unthreaded base. Ensure the O-ring is properly seated before securing. Route the sensor cable through the 1/2-in NPT fitting and tighten to maintain the explosion-proof seal. For Velomitor CT sensors, the tall cap option is required. Always verify that the housing is correctly grounded per local electrical codes.

Maintenance & Reliability

Inspect the O-ring periodically for cracks or wear and replace if needed. Clean the exterior with a damp cloth; avoid harsh solvents that could damage the neoprene seal. Check the NPT fitting for tightness after any cable adjustments. With proper care, this housing provides long-term protection, reducing replacement costs and improving system uptime.

Compatibility & Integration

The 21128-01-02 works with Bently Nevada velocity sensors such as the Velomitor CT and 9200 Seismoprobe. When using a Velomitor sensor, cable part number 89477-AA is required for connection to a monitor. The housing supports both standard and isolated base sensor configurations with the appropriate cap option.

FAQs about the 21128-01-02

Q: What is the temperature range for the 21128-01-02?

A: It is rated from -29°C to +121°C (-20°F to +250°F).

Q: Can this housing be submerged?

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

Q: What cable is needed for a Velomitor sensor?

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

Q: Is the 21128-01-02 explosion-proof?

A: The CA21128 version is CSA certified for hazardous areas; the 21128-01-02 is for non-hazardous environments but includes an explosion-proof fitting.

Q: What is the weight of the housing?

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

Product Support & Availability

The 21128-01-02 is in stock and ready to ship from Petro Auto Tech. Contact our team for pricing and lead times. We are your trusted source for Bently Nevada industrial automation parts.