Group 2 is not a quality tier
Group 2 is a configuration and size-family reference, not a quality grade. It helps narrow the casing, impeller, shaft, bearing-housing and seal interfaces that must be checked before a replacement part is approved.
ANSI Pumps Pro is an independent aftermarket manufacturer and is not affiliated with or endorsed by Flowserve. Flowserve and Durco model names are used only for identification and cross-reference.
What Makes a Group 2 Parts Request Different?
A Group 2 request can still be incomplete if it omits pump size, impeller trim, material, seal arrangement or the drawing revision. The same broad family name may cover different component details, and an individual replacement part must fit the mating parts that remain in service. Treat the nameplate, installed drawing or parts list as the controlling evidence.
For a planned outage, identify whether the requirement is one component, a wet-end assembly, a power-end component or a complete replacement scope. This prevents a quote for a nominally similar part from being mistaken for approval of the entire pump configuration.
Typical Mark III Component Identification Starting Points
| Typical item reference | Component | What to confirm before quote |
|---|---|---|
| 100 | Casing | Group, size, nozzle/flange interfaces, material and pressure requirement |
| 103 | Impeller | Group/size, vane configuration, diameter/trim, material and shaft interface |
| 105 | Shaft | Group, shaft dimensions, material and bearing/seal interfaces |
| 106 | Rear cover plate | Seal-chamber or cover configuration, material and gasket interface |
| 108 | Bearing housing adapter | Group and power-end interface |
| 119 | Bearing housing | Group, bearing arrangement and mounting/interface details |
Item numbering can vary by documentation and configuration. Use the installed pump drawing, parts list or nameplate as the controlling reference. The table is an identification starting point, not a universal Durco Mark III parts code list.
Verify the Pump Size, Group and Mating Interfaces
Start with a clear photograph of the nameplate and the complete pump. Record model, size, group, serial or tag number, rotation, driver speed and any visible modifications. For the casing, confirm nozzle size and location, flange standard, mounting relationship, casing material and pressure requirement. For the impeller, confirm outside diameter or trim, vane configuration, balance requirement, keyway and shaft fit.
For shaft, seal and power-end parts, measure or document the shaft diameter, bearing arrangement, seal-chamber dimensions, sleeve arrangement, adapter and coupling interfaces. If the pump has been repaired previously, ask whether the installed component differs from the original drawing. A replacement must match the pump as configured, not merely the family name printed on an old quotation.
Wet-End and Power-End Scope
Group 2 wet-end work may include casing, impeller, shaft, wear rings, rear cover, gaskets and related hardware. Power-end work may include shaft, bearings, bearing housing, adapter, lubrication components and coupling interfaces. When only one part is replaced, inspect the mating components for wear, corrosion, erosion and prior machining.
For a complete wet-end replacement, confirm the operating duty and impeller trim as well as dimensions. A dimensionally similar impeller can still produce a different head, flow, efficiency or NPSH result. Dimensional fitment, hydraulic suitability, material compatibility and operating conditions are separate approval gates.
Materials Are a Service Decision
Available metallurgy should be reviewed against the exact fluid, concentration, temperature, solids, corrosion history and project specification. ANSI Pumps Pro’s documented material range includes WCB, CF8M, CD4M/CD4MCu, CN7M, Hastelloy grades, CZ100/nickel options, titanium and zirconium, subject to the selected component and service review.
Do not turn that range into a chemical-name-only recommendation. Alloy 20 / UNS N08020 and CN7M are not interchangeable labels, and C-276 / UNS N10276 and CW2M are not interchangeable casting designations. The component, product form, heat treatment, weld repair requirements and service conditions all matter.
Minimum Information for a Group 2 Parts Quote
- Mark III / pump model reference;
- Group 2 confirmation, if known;
- pump size and nameplate photograph;
- part or item reference, if known;
- component photographs and installed-condition notes;
- material requirement and fluid service;
- impeller diameter or configuration, if applicable;
- seal chamber and shaft interface, if applicable;
- fluid concentration, temperature and solids;
- required drawings, MTR, PMI, balance or inspection documents; and
- target delivery date and outage constraints.
Request a Group 2 fitment review
Send the nameplate, pump size, part reference, photographs, material and seal information. We can review whether the requirement is best handled as an individual component, wet-end assembly, power-end component or complete replacement scope.
Request a Group 2 parts review
Start an OEM part-number cross-reference
Review aftermarket pump solutions
Frequently Asked Questions
What does Group 2 mean on a Durco Mark III parts request?
It identifies a configuration and size-family reference. It is not a quality grade and does not replace checking the exact model, size, drawing, material and interfaces.
Are typical Mark III item numbers universal?
No. Item numbering can vary by documentation and configuration. Use the installed drawing, parts list or nameplate as the controlling reference.
Can Group 2 parts be quoted from a pump size alone?
A size is a useful starting point, but a controlled quote normally also needs the component, material, impeller or shaft details, seal arrangement and required documentation.
What is the difference between a Group 2 wet-end and power-end request?
A wet-end request concerns hydraulic and wetted components such as casing and impeller. A power-end request concerns shaft, bearings, housing, adapter and coupling interfaces. The two scopes require different fitment checks.
For the broader Flowserve parts comparison, see the Flowserve pump parts OEM versus independent aftermarket guide. For the general dimensional boundary, see the ANSI pump dimensions and interchangeability guide.
