21128-12-02 | Bently Nevada 3/4-in NPT Tall Cap Velocity Transducer Housing

What Is the 21128-12-02?

When hose-directed water, corrosion, or physical abuse threatens velocity sensors, the 21128-12-02 provides robust protection. This Bently Nevada housing, constructed of 303 stainless steel, meets NEMA 4X and IP65 requirements when properly installed. Designed for non-hazardous environments, it includes a tall cap option for Velomitor CT sensors or 9200/74712 Seismoprobe with isolated base.

Key Features & Technical Specs

• Mounting thread and cap option: 3/4-in 14 NPT with tall cap.
• Cable exit fitting: 1/2-in NPT explosion-proof fitting.
• Temperature rating: -29°C to +121°C (-20°F to +250°F).
• Moisture resistant but not submersible.
• O-ring material: Neoprene.
• Weight: 1.6 kg (3.55 lb) without sensor or fittings.
• Internal mounting thread: 1/2-in 20 UNF for 21128 and CA21128.
• Outlet port size: 1/2-in NPT.

One distinctive spec is the tall cap option, which allows installation of Velomitor CT sensors—a feature not available in standard caps.

Installation Guide

Install the 21128-12-02 by threading the 3/4-in NPT mounting into a compatible sensor. Use cable part number 89477-AA to connect the Velomitor sensor to a monitor. Ensure the 1/2-in NPT explosion-proof fitting is properly sealed. For optimal protection, verify the housing meets NEMA 4X and IP65 requirements after installation.

Routine Care & Reliability

Regularly inspect the O-ring for wear and replace if damaged. Clean the stainless steel exterior with a damp cloth to remove contaminants. Avoid submerging the housing, as it is moisture-resistant but not submersible. Periodic checks of the cable exit fitting prevent moisture ingress.

Compatible Systems

The 21128-12-02 integrates with Bently Nevada Velomitor CT sensors and 9200 or 74712 Seismoprobe sensors with isolated base. It requires cable 89477-AA for Velomitor connections. This housing is designed for use with Bently Nevada monitoring systems.

Common Questions

Q: What is the temperature range for the 21128-12-02?

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

Q: Can the 21128-12-02 be used in hazardous areas?

A: The housing is designed for non-hazardous environments; the 1/2-in NPT explosion-proof fitting provides additional safety.

Q: What is the weight of the 21128-12-02?

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

Q: Is the 21128-12-02 submersible?

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

Q: What O-ring material is used?

A: The O-ring is made of Neoprene.

Product Support & Availability

The 21128-12-02 is in stock and ready to ship. Contact Petro Auto Tech for pricing and availability. Please verify current lifecycle status with Petro Auto Tech before ordering.