ANSI/ASME B73.1 power ends

ANSI pump shaft frame groups

A replacement process-pump shaft is a power-end part. The bearing frame (Goulds 3196 ST through X17, Durco Mark 3 Group 1 through 3, or one of the families that interchange with the 3196) fixes the journals, bearings, seal sleeve seat and coupling end, and the bearings themselves are the fastest way to identify it.

ANSI/ASME B73.1 standardises the pump envelope and the hydraulic sizes so that pumps interchange on a baseplate. It does not standardise the shaft. Each maker groups its hydraulic sizes onto a few bearing frames (power ends) of its own design, the shaft belongs to the power end, and one hydraulic size can be built on more than one frame. The size designation alone therefore does not identify the shaft; the frame does.

The discriminators are the bearings and the journals they sit on. Every frame below runs a deep-groove radial bearing inboard (impeller side) and a thrust bearing outboard (coupling side). The pair of bearing numbers, read off the old bearings or the IOM, names the frame; the journal diameters confirm it with a micrometer. 25 frames across 7 families are listed. Within a family the pair names the frame (XLT and X17 share one, and the second table says what separates them); the second table also shows which pairs are shared across families.

Every number is the one the matching catalog part loads into the configurator, dimensioned from the pump makers' installation, operation and maintenance manuals and brochures. Journals, bearings and the k5 bearing-seat fit are published for every frame and always shown. A bearing span the maker does not publish is a dash here; the part page shows a configurable value in its place, estimated by ANSI analogy; confirm against your shaft.

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Frame groups: bearings, journals and span

Journal diameters in inches at the finished size; the fit is the ISO 286 class the journals are cut to with its deviations from nominal. A dash in the span column means the maker does not publish it; the part page shows a configurable value, estimated by ANSI analogy; confirm against your shaft.

Download this table (CSV)

Identify the frame from the bearing pair

Read the two bearing numbers off the old bearings. A pair shared by several frames of the same geometry means the parts interchange; where the geometry differs, the last column names the published dimension that separates them.

Reading the frame off the pump

Start with the bearing-frame nameplate or the pump data sheet, which give the model and frame directly. If they are gone, pull the bearing numbers: the radial bearing sits inboard, nearest the impeller; the thrust bearing (angular-contact or double-row) sits outboard at the coupling. Match the pair in the second table, then mic the journals against the first.

Several frames share a bearing pair across families because the pumps are built to interchange: Goulds’ own 3796 self-primer and 3996 vertical in-line mount the 3196 power end, and Summit 2196, Griswold 811 and PumpWorks PWA are parts-interchangeable with it. The Durco Mark 3 is a separate geometry: ANSI B73.1 fixes the envelope, not the shaft, and the two makers chose different bearings and spans.

Where the numbers come from

Bearing numbers, bores and journal diameters are the makers’ published values: the Goulds i-FRAME IOM bearing-fit and bearing-type tables and the Construction Details in its brochure; the Flowserve Durco Mark 3 IOM journal-seat figures and bearing table, with the Group 2 overhang and sleeve seat from its brochure; the Summit 2196 manual’s bearing table for the interchange cluster. The threaded impeller nose on each catalog part is representative, sized under the impeller register, because the makers do not publish it; every dimension a maker does not publish is flagged on the part page as estimated by ANSI analogy; confirm against your shaft.

Goulds, 3196, 3796, 3996, Durco, Mark 3, Summit, Griswold, PumpWorks, and all other pump model, frame, and brand names shown are trademarks or trade names of their respective owners. Great Lakes Shafts is an independent manufacturer and is not affiliated with, sponsored by, or endorsed by any of them. These are aftermarket replacement shafts machined to fit the referenced pumps, dimensioned to the pump makers’ published data; the names are used only to identify the equipment our parts fit.

Related: Pump shafts · k5 bearing-seat fit · Shaft fits and tolerances · Keyway and keyseat dimensions.

Frequently Asked Questions

These references are for specifying a part; every value here is one the configurator applies when you build one. Numbers are representative of the standard; check them against your part and its mating components before ordering. See all guides on the guides page.