Product Overview

The Bently Nevada 21000-28-05-00-060-03-02 is a heavy-duty, explosion-proof proximity probe housing designed to facilitate external probe adjustment while the machinery remains operational. This assembly provides a robust environmental seal for 3300 XL 8mm and 5mm proximity probes, shielding sensitive transducers from hazardous conditions, high-pressure washdowns, and mechanical damage. Primarily utilized in critical Turbine Supervisory Instrumentation (TSI) setups, this aluminum housing allows maintenance teams to set the precise "gap" voltage without dismantling the machine casing. By ensuring stable mounting and superior protection, the 21000 series housing minimizes signal noise and prevents false trips in high-vibration rotating machinery such as steam turbines, centrifugal compressors, and large industrial motors.

Multi-Segment Configuration Analysis

The 21000 series utilizes a complex suffix string to define mechanical dimensions, material types, and international safety certifications.

21000-28 (Base Model & Material)

The -28 prefix designates an Aluminum Probe Housing with 3/4-14 NPT conduit connections. Aluminum offers an excellent balance of corrosion resistance and lightweight durability for most industrial environments.

05-00-060 (Probe & Thread Options)

The "05" indicates the housing is configured for a 3/8-24 UN-2A probe thread, specifically designed for standard 3300 XL 8mm probes. The "00" confirms no unthreaded length is required for this specific sleeve, while "060" defines the sleeve length as 6.0 inches (152 mm), providing the necessary reach to access the shaft target through the machine's outer shell.

03-02 (Explosion Proof & Calibration)

The "03" suffix confirms the assembly meets North American and International (ATEX/IECEx) explosion-proof requirements, making it suitable for Class I, Div 1 locations. The "02" identifies the inclusion of a standard probe cable seal and adjustment nut configuration for simplified field calibration.

Essential Physical & Technical Data

Field Installation Guidelines

Before installing the 21000-28-05-00-060-03-02, ensure the mounting hole on the machine casing is tapped correctly to accept the housing base. Apply a high-quality thread sealant to the NPT connections to maintain environmental integrity. When gapping the probe, use the external adjustment nut to move the probe toward the shaft until the desired DC Gap Voltage (typically -10.0 VDC for a mid-scale reading) appears on your voltmeter.

Tighten the locking nut to a maximum torque of 4.5 N·m (40 in·lb) to prevent the probe from shifting due to machine vibration. Ensure the internal cable is routed with a minimum bend radius of 25.4 mm (1 inch) within the housing dome to prevent coaxial fatigue. Always verify that the electrical grounding of the housing is bonded to the machine case to eliminate stray voltage interference.

Engineering Performance Advantages

This housing assembly excels in protecting the critical 3300 XL system from "gap drift" caused by thermal expansion or mechanical loosening. The aluminum construction dissipates heat efficiently, protecting the internal probe electronics in high-temperature turbine applications. Its explosion-proof rating ensures safety in volatile gas environments common in the oil and gas sector. Furthermore, it integrates seamlessly with Bently Nevada 3500 racks and Honeywell Experion DCS via the Proximitor signal chain, providing a stable mechanical platform that translates to higher signal-to-noise ratios and more reliable diagnostic data.

Delivery Information

Delivery time: 3-5 days when payment finish, BY DHL/FEDEX/UPS.

We utilize anti-static industrial packaging and high-density foam inserts to ensure the 21000-28 housing and its precision-machined sleeve arrive without thread damage or structural misalignment.

Technical Consultation (FAQ)

Q1: Can I adjust the probe depth while the machine is running?

A1: Yes. The primary advantage of the 21000 series is the ability to adjust the probe gap externally through the housing sleeve without shutting down the equipment or exposing the interior of the machine.

Q2: Does this housing include the proximity probe itself?

A2: No. This is a housing assembly. The proximity probe (e.g., 330101-00-08-10-02-00) must be ordered separately to match your specific system requirements.

Q3: Why choose aluminum over the stainless steel version?

A3: Aluminum is preferred for standard industrial applications due to its lighter weight and lower cost while still providing excellent protection against moisture and dust. For highly corrosive offshore or chemical environments, we recommend the 21000 stainless steel variants.

Q4: What is the purpose of the "060" sleeve length?

A4: The sleeve length must match the distance between your mounting surface and the target shaft. A 6.0-inch sleeve ensures the probe can be positioned correctly even if the machine casing is thick or requires an offset mount.