Bently Nevada 21000 vs 32000 Probe Housings Selection and Ordering-Code Guide

Select a 21000 or 32000 from the installed geometry, area-classification basis, enclosure requirement, probe option, cable length, conduit hardware, and machine-case thread. The 32000 is the metric version of the newer PPS housing family, but it is not an unconditional replacement for a 21000. If the installation needs the newer PPS housing with inch-based dimensions, the 31000 may be the relevant family instead.

The Main 21000 and 32000 Selection Differences

First determine whether the installation must retain an existing 21000 arrangement or can be engineered around the newer PPS housing. Compare housing-level characteristics separately from options that belong to the installed probe.

Bently Nevada document 141600 Rev. AC defines the 21000 order-code fields, while document 141610 Rev. R defines the 32000 order-code fields.

The housing family is only one part of the decision. A matching base number does not confirm probe type, approval option, cable length, reach, fittings, or mounting thread.

Where the Two Housing Families Differ in the Field

The practical differences appear in four areas: housing construction, hazardous-area treatment, dimensional coding, and physical interfaces. Each area must be checked against the installed drawing and project requirements.

Aluminum 21000 Housing vs Conductive PPS 32000 Housing

The 21000 uses an aluminum body with an AISI 304 stainless steel probe sleeve. It is an all-metal housing for externally mounted reverse-mount proximity probes.

The 32000 uses a glass-reinforced polyphenylene sulfide body containing conductive fibers. Its probe sleeve and retaining chain are AISI 304 stainless steel, while the outer sleeve and exterior screws are AISI 303 stainless steel. The conductive PPS body is certified to Type 4X and verified to IP66 for environmental protection.

Material alone does not decide compatibility. A replacement must retain the required mounting thread, sleeve geometry, conduit entry, sealing arrangement, and access for probe adjustment.

Explosion-Proof Enclosure Requirements vs Intrinsically Safe Installations

The probe approval suffix and the enclosure approval are separate checks. Option A28 or A30 identifies an approval option for the probe. It does not make the complete housing explosion-proof.

The 32000 provides mechanical and environmental protection, but its housing is not explosion-proof. It can be used in an intrinsically safe installation when the selected transducer system, barriers, wiring, and controlled drawing support that use.

For North American end users, the manufacturer identifies CA21000 and CA24701 as the CSA explosion-proof housing versions. Other end-user countries require the applicable 21000 or 24701 execution and country-specific approval review. Do not release a replacement from the base family or fitting description alone.

Inch-Based 21000 Geometry vs Metric 32000 Geometry

Both families use six option groups after the housing number, but their C and D fields do not use the same unit system.

• On a 21000, C is the standoff length in tenths of an inch and is normally ordered in 0.5 in increments. D is the probe penetration in tenths of an inch.
• On a 32000, C is the standoff length in tens of millimeters. D is the probe penetration in whole millimeters.

For example, D054 on a 21000 means 5.4 in, or about 137 mm. D090 on a 32000 means 90 mm, or about 3.54 in. The numeric code cannot be transferred without converting the required physical dimensions.

NPT, BSP, M24, M25, and PG Interface Options

The E and F fields describe different interfaces. E specifies the conduit fittings, plugs, reducers, or cable-seal hardware supplied with the housing. F specifies the outer sleeve and machine-case mounting thread.

A 32000 can use metric conduit fittings while retaining a 3/4-14 NPT mounting thread. For example, E07 supplies one PG21 x M20 fitting and two plugs, while F02 specifies a 3/4-14 NPT mounting thread. The word "metric" in the family description does not prove that every interface is metric.

When to Retain a 21000, Specify a 32000, or Check the 31000 Instead

Retain the installed 21000 geometry when the maintenance task requires like-for-like mechanical fit, the existing drawing and approval record are tied to that family, or a change would require unapproved machine-case work.

Specify a 32000 when the project accepts the non-explosion-proof PPS housing, uses metric C and D dimensions, and the selected probe, fittings, thread, barriers, and environmental requirements all match. The 32000 is suitable for externally mounted radial vibration or Keyphasor probes through a machine case. A dual axial-probe arrangement requires a different housing family.

Check the 31000 instead when the project needs the newer PPS housing but the installation is defined by inch-based standoff and penetration dimensions. The 31000 and 32000 share the PPS housing concept, but the 31000 uses the English ordering structure.

Treat every 21000-to-32000 change as an engineered replacement. The manufacturer recommends the newer 31000/32000 family where an explosion-proof housing is not required, but that recommendation does not establish a direct mechanical substitute for every 21000 code.

How to Decode a 21000 Ordering Code

The 21000 structure is 21000-AA-BB-CC-DDD-EE-FF. Decode all six fields before comparing two assemblies because a shared 21000 prefix identifies only the housing family.

A and B: Probe Selection, Approval Option, and Cable Length

The A field identifies the installed probe and relevant probe options. The B field identifies the integral probe cable length.

A probe approval option is not a complete enclosure approval. Confirm the housing execution, area classification, barriers, wiring method, and project certificate requirements separately.

C and D: Standoff and Probe Penetration in Inches

C00 means that no standoff adapter is included. When a standoff is required, the standard 21000 C field runs from 15 to 75, representing 1.5 to 7.5 in, and is ordered in 0.5 in increments.

The D field is a three-digit penetration value in tenths of an inch. D054 is 5.4 in, D133 is 13.3 in, and D244 is 24.4 in. Always preserve leading zeros because the field format helps distinguish a complete code from an incomplete transcription.

The mechanical reach check is:

Required housing reach = C standoff length + D probe penetration

For a 21000 with a 0.5 m probe cable, the published maximum C + D dimension is 13.5 in, or 343 mm. With a 1.0 m probe cable, the maximum is 29.2 in, or 742 mm. A 21000 C + D dimension above 300 mm, or 12 in, requires additional sleeve support near the probe.

E and F: Fittings and Machine-Case Thread

The E field lists the supplied conduit hardware. The F field lists the machine-case mounting interface.

An E01 fitting does not convert a standard housing into a CA21000 enclosure. The delivered housing marking and the applicable approval record control that decision.

Worked 21000 Examples and Long-Sleeve Checks

The same housing family can represent substantially different probe and reach configurations. Each code requires a configuration-specific engineering check; none of these checks constitutes installation approval.

Compare complete 21000 assemblies only after confirming the required A, B, C, D, E, and F fields.

How to Decode a 32000 Ordering Code

The 32000 structure is 32000-AA-BB-CC-DDD-EE-FF. Its A and B fields resemble the newer 31000 structure, while C, D, and several E options use metric dimensions and fittings.

A and B: Probe, Connector-Protector, Approval, and Cable Options

The A field combines the probe family with connector-protector and approval selections. The B field identifies the probe cable length.

A29 and A30 are not temperature-range codes. If an installation has a separate temperature requirement, confirm it from the exact probe and complete transducer-system documentation.

C and D: Standoff and Probe Penetration in Millimeters

C00 means no standoff adapter. Standard nonzero C options run from C04 to C20, representing 40 to 200 mm in 10 mm increments. The D field runs from D025 to D760 and represents penetration in whole millimeters.

For a 32000 with a 0.5 m cable, the published maximum C + D dimension is 394 mm. With a 1.0 m cable, the maximum is 760 mm. A C + D dimension above 305 mm requires sleeve support near the probe. Penetration between 25 and 50 mm may require a machine-case counterbore to control side-view or rear-view effects.

E and F: Metric Fittings and Mounting Thread

The 32000 E options include M25, M20, DIN PG11, and PG21 x M20 arrangements. The F field remains an independent mounting choice.

F01 specifies M24 x 3. F02 is required when a standard standoff adapter is ordered, so a metric C field can still be paired with an NPT machine-case thread.

Worked 32000 Examples and Geometry Checks

The three codes differ in probe approval, cable length, standoff, penetration, and conduit hardware even though all use F02 mounting. None exceeds the applicable C + D limit or the 305 mm sleeve-support threshold.

Compare complete 31000 and 32000 assemblies only after deciding which dimensional system the installation requires.

How to Check Whether a 21000-to-32000 Change Will Fit

A family change affects more than housing material. Complete the checks below in sequence so the mechanical housing, probe chain, area-classification basis, and commissioning record remain consistent.

Preserve the Complete Probe-to-Proximitor Chain

Record the full probe, extension-cable, and Proximitor Sensor numbers before removing the installed housing. Preserve the probe family, electrical system length, connector construction, target basis, barriers, and monitoring-channel requirements.

If the project changes the installed probe or cable, match the complete 3300 XL chain rather than approving the replacement from the housing code alone. The housing controls mechanical access and protection; it does not establish electrical compatibility by itself.

Compare C + D Against the Cable-Length Limit

Convert both families to one working unit, then calculate C + D. Check that result against the limit for the selected B cable option and record whether long-sleeve support is required.

Do not treat nominal reach as the final probe gap. The sleeve and reverse-mount probe still need the documented adjustment range, target clearance, and approved final gap procedure.

Match the Machine-Case Thread, Conduit Entry, and Standoff

Verify F against the existing machine-case boss. Verify E against the conduit or armored-cable entry. Verify C against the required stand-off distance and available external clearance.

An F02 code on both assemblies confirms a 3/4-14 NPT mounting selection, but it does not confirm equal reach, housing profile, conduit entry, or approval status.

Confirm the Area Classification and Enclosure Requirement

Separate five records: probe approval, housing approval, intrinsic-safety barrier, field wiring method, and end-user country. All five can affect acceptance.

If the housing itself must be explosion-proof, stop the 32000 substitution review and verify the approved housing family for the jurisdiction. A probe with multiple approvals does not change the 32000 enclosure classification.

Support Long Sleeves Before Commissioning

Provide support near the probe when the applicable C + D threshold is exceeded. Confirm any support or oil seal that passes through an inner bearing housing, and prevent conduit or cable loads from acting on the sleeve.

After installation, follow the site procedure for gap voltage, signal polarity, dynamic response, monitor indication, alarm handling, enclosure closure, and return-to-service authorization.

What to Send With a Probe-Housing RFQ

A complete RFQ lets maintenance, engineering, procurement, and our sourcing team compare the same installed configuration. Send measured and documented values rather than descriptions such as "standard housing" or "same as the old one."

When we review an RFQ, we can compare the submitted code with the requested configuration and state the offered identity, condition, included hardware, documentation, warranty, and dispatch basis. Your engineering team should approve the mechanical fit, hazardous-area basis, and commissioning procedure.

FAQs

Q1. What Does F00 Mean on a 32000 Housing?

F00 means no outer sleeve, retainer, or retaining nut is included. Do not treat an F00 configuration as a complete mounted housing. Confirm which existing components will be reused and whether their material, condition, and dimensions satisfy the installation drawing.

Q2. Can I Order a 21000 or 32000 Housing Without a Probe?

Yes. The ordering tables allow A00 for no probe, and B00 must accompany that selection. The remaining C, D, E, and F fields still need to match the required standoff, sleeve, fittings, and machine-case interface.

Q3. Can These Housings Be Used for a Dual Axial-Probe Arrangement?

Not as a direct dual-probe arrangement. The 21000 and 32000 housings are intended for one externally mounted reverse-mount probe. Check the 21022 dual axial-probe housing family when two axial probes must share a purpose-built arrangement, then verify the machine drawing and probe chain.

Q4. Is 21000-28-05-00-47-01-02 a Valid Ordering-Code Format?

Treat it as unverified. The official 21000 structure uses a three-digit D field. A 4.7 in penetration would normally appear as D047, but do not normalize the code until the physical nameplate, original purchase record, or controlled machine drawing confirms the intended value.

Q5. Why Can the Probe Label Become Hidden Inside a Long Sleeve?

The label position is fixed along the probe cable, while the C + D reach changes how much cable sits inside the sleeve. A long reach can place the label inside the assembly. Record the probe part number and serial number before installation, and check the published visible-label limit for the selected cable length.

Send the Full Housing Code for an Availability and Configuration Review

Send your RFQ to Apter Power with the complete housing code, nameplate photographs, machine drawing, probe-chain numbers, quantity, destination, and required date. We can review the requested configuration against the offered identity, condition, included hardware, documentation, warranty, and dispatch basis. Your engineering team remains responsible for mechanical fit, area-classification acceptance, installation, and return to service.