Aurora 3550 Discontinued: Replacement Pump, Parts & Fitment Options

Is the Aurora 3550 Discontinued?

Yes. Pentair currently lists the Aurora 3550 ASME/ANSI B73.1 process pump as discontinued. That status does not, by itself, mean that every installed pump must be replaced or that OEM support has ended. Pentair also maintains an Aurora parts-and-service route. Start with the condition and records for the pump in your plant.

The practical question is whether to continue repair, replace an identified component, review a wet end or power end, or assess a complete pump replacement. Each option needs evidence from the installed configuration and its operating duty.

Identify the Installed Aurora 3550 Configuration

“Aurora 3550” identifies a pump family, not one universal build. Pentair’s current product information lists 3550-S, 3550-M/L and 3550-XL groups; the historical IOM manual refers to S, M, L and XL frames. Use the installed nameplate and applicable drawings to identify the unit rather than inferring its frame from the family name.

If the nameplate is missing or incomplete, collect clear photos of the whole pump, bearing frame, seal area, suction and discharge connections, baseplate, coupling and any casting marks. Add measured interfaces and known duty data. Do not identify a pump from appearance alone.

The table below preserves the historical size and ANSI designation mapping published for the Aurora 3550. Use it to identify a likely configuration, then confirm the installed pump against its nameplate and applicable records. The frame label can vary across documents; do not use this table alone to release a replacement.

Source: Pentair Aurora 3500 Series brochure. The IOM manual notes that a 3 × 4 – 7 / A70 entry was developmental; it is not included in this size list.

Complete Pump, Wet End, Power End or Individual Part?

Decide what needs to be replaced before comparing suppliers. The right scope depends on the damaged assembly, condition of retained parts, current duty, available records and required documentation.

“Wet end” and “power end” are not universal bills of material. Ask the supplier to list every included component and identify what is retained, replaced, inspected and documented.

Replacement scope should be defined by the assembly and verified interfaces, not by the family name alone.

For a general explanation of assembly boundaries, see ANSI pump wet-end replacement packages. For part identification, use the OEM part-number cross-reference.

What ASME B73.1 Means for an Aurora 3550 Replacement

ASME describes B73.1 as covering dimensional interchangeability for pumps of the same standard dimension designation, including specified mounting dimensions, suction and discharge nozzle size and location, input shafts, baseplates and foundation bolt holes. This provides a useful starting point for reviewing installation interfaces.

It does not establish that two manufacturers’ pumps have identical internal registers, casing passages, impellers, shaft threads, bearing-frame internals, seal chambers, materials or performance curves. Nor does the standard prove that a field-modified installation will accept a replacement without adjustment.

For a broader explanation of the standard’s scope, see the ASME B73.1 interchangeability guide.

If the installed pump is a different brand or platform, use the competitor replacement index for that equipment. A cross-reference for another model does not establish Aurora 3550 component interchangeability.

Dimensions and Interfaces to Verify Before Replacement

Compare the proposed pump drawing with the installed pump and piping. Include field changes and the equipment that will be retained.

Use approved GA data and site measurements to compare the installed nozzles, mounting, shaft/coupling and driver interfaces.

Use drawing dimensions and site measurements where available. Do not add assumed tolerances or declare a fit from a nominal size alone.

Verify Hydraulic Compatibility Separately

Pentair lists historical Aurora 3550 family maxima of 4,200 GPM, 725 ft head, 650°F and 375 psig. These are product-family limits published by Pentair, not the duty point or allowable operating envelope for a particular installed pump.

For the replacement review, gather normal and expected operating flow, total dynamic head, speed, impeller diameter, liquid specific gravity and viscosity, temperature, vapor pressure, solids or entrained gas, NPSH available, motor data and control method. At the required duty and expected operating conditions, compare system NPSHA with the supplier’s NPSHR curve and check the pump input-power curve against the retained or proposed driver. Apply the project’s specified NPSH-margin criterion rather than assuming a universal value. The Hydraulic Institute pump-curve guide explains the head, input-power, efficiency and NPSHR curves.

If the process or system has changed, treat the request as a new hydraulic selection. Use the ANSI pump selection worksheet to organize available inputs; final selection still requires engineering review of the actual duty and pump data. See the technical resources library for performance-curve and material resources.

Check the Seal Arrangement and Wetted Materials

Before proposing seal reuse, record the manufacturer and model, single or dual arrangement, cartridge or component seal, shaft or sleeve diameter, setting dimension, chamber and gland interfaces, flush/quench connections, and any barrier or buffer system. Confirm seal compatibility against the proposed chamber and the actual process conditions.

For materials, identify the grade for each relevant wetted component instead of requesting a general label such as “stainless” or “Hastelloy.” Provide chemical composition and concentration, normal and upset temperatures, contaminants, solids, pH or chloride information where relevant, cleaning conditions and corrosion history. Material selection is service-specific; no alloy choice should be approved from the chemical name alone.

Explore the aftermarket parts and service route when the request concerns a specific part or assembly. Confirm coverage and exact fitment against the model, drawing, part reference and configuration.

What to Send for an Aurora 3550 Replacement Review

Send what is available; mark unknown fields instead of estimating them. A useful request includes:

For an initial selection path, use the pump selection worksheet. For chemical-material context, see the chemical resistance guide. For a parts request, provide the OEM part number, position reference or drawing when available. The quotation should state the included scope, fitment evidence and documentation.