Identify the Exact 3196 STX Impeller First
A Goulds 3196 STX impeller should not be selected from the frame name alone. Match the replacement to the installed hydraulic size, existing impeller reference, finished trim diameter, material and mating wet-end configuration.
For current i-FRAME documentation, the small-frame designation is commonly shown as STi. Older installed equipment and maintenance records may use STX terminology. When generation matters to the component interface, confirm the actual installed configuration.
| Pump size | Frame family | Component | OEM reference to verify | RFQ check |
|---|---|---|---|---|
| 1 × 1.5 – 6 | STX / STi | Item 101 Impeller | 076781 | Reference + trim + material |
| 1.5 × 3 – 6 | STX / STi | Item 101 Impeller | 076792 | Reference + trim + material |
| 2 × 3 – 6 | STX / STi | Item 101 Impeller | 0B10176 | Reference + trim + material |
| 1 × 1.5 – 8 | STX / STi | Item 101 Impeller | 076793 | Reference + trim + material |
| 1.5 × 3 – 8 | STX / STi | Item 101 Impeller | 076794 | Reference + trim + material |
An OEM number is useful, but it should still be reviewed together with the pump size and installed component. A part number alone does not establish the finished impeller diameter, material or condition of an altered pump.
Threaded Impeller Fit: What Must Be Verified
A Goulds 3196 open impeller should not be described as a conventional cylindrical-bore impeller located by a shaft keyway. The impeller-to-shaft connection uses a threaded interface, and the replacement review must establish the actual shaft/impeller interface, sealing feature, axial relationship and hydraulic geometry.
| Check | Why it matters | Preferred evidence |
|---|---|---|
| Pump size | Identifies the hydraulic family | Nameplate / model record |
| Frame / generation | Narrows mechanical configuration | Frame marking / documentation |
| Impeller reference | Cross-references the existing part | Parts list / removed-part marking |
| Threaded shaft interface | Confirms mechanical attachment | Approved drawing / installed dimensions |
| Finished outside diameter | Confirms hydraulic trim | Curve / drawing / measured impeller |
| Rear pump-out vane geometry | Affects hydraulic and axial behavior | Existing part / approved geometry |
| Axial reference geometry | Affects installed running position | Drawing / mating wet-end dimensions |
Impeller Trim Diameter Is Not the Same as Running Clearance
Two dimensions are commonly confused during replacement work. They should be reviewed separately before an impeller is released for manufacture.
Finished Trim Diameter
Controls the hydraulic performance associated with the impeller and applicable pump curve. Verify the current OD, operating speed, duty point and motor limitation.
Operating Clearance
Controls the running relationship between the open impeller and mating pump surfaces. Use the applicable IOM for the exact configuration and service temperature.
Do not assume the nominal “6-inch” or “8-inch” size suffix is the finished diameter to manufacture. A previously trimmed pump may use an impeller substantially different from the maximum diameter available for that hydraulic size.
Material Selection: CF8M, CD4MCuN and Cast Ni-Cr-Mo Alloys
Material selection should start with the actual process service rather than the alloy name printed on an old quotation. Capture the liquid, concentration, operating temperature, contaminants, chlorides where relevant, solids and observed failure mode.
| Material route | Typical procurement description | What must be confirmed |
|---|---|---|
| CF8M | Cast austenitic stainless steel / 316-family reference | Fluid chemistry, chlorides, temperature, solids and required casting specification |
| CD4MCuN | Duplex stainless casting | Exact grade, project specification, service chemistry and certification scope |
| Cast Ni-Cr-Mo alloy | Often requested commercially as “Hastelloy C-276” service | Exact casting grade, UNS designation, chemistry and project requirement |
CF8M, duplex stainless and Ni-Cr-Mo alloys should not be reduced to a simple “good / better / best” ranking. If the existing impeller corroded, eroded or cracked, include photographs and process conditions so the failure mechanism can be reviewed before changing metallurgy.
Inspection and Documentation Before Shipment
Inspection requirements should be defined during quotation instead of being added as generic promises after an order is placed.
| Verification | Purpose |
|---|---|
| Part / drawing cross-reference | Confirms the intended component |
| Finished impeller diameter | Confirms the required trim |
| Thread and hub interface | Confirms mechanical fit |
| Relevant axial dimensions | Confirms installed relationship |
| Vane / pump-out vane geometry | Confirms required hydraulic configuration |
| Runout | Checks machining / rotating accuracy |
| Material traceability / MTR / PMI | As specified in the agreed inspection scope |
| Balance acceptance | As specified by PO or inspection plan |
If a balance requirement is specified, state the applicable acceptance criterion on the purchase order or agreed inspection plan. Documentation scope should be agreed at quotation stage; do not assume every replacement impeller automatically includes every inspection document.
What to Send for an STX Impeller RFQ
The fastest path to a reliable replacement review is to send the installed evidence before the impeller is cast or machined.
STX Impeller Engineering Checklist
Copy these fields into your inquiry or use them as the minimum data set for a fit review.
