Pumps & Fluid Handling

What pump parts get quoted here?

The turned and milled parts that wear out, or that change between pump revisions: shaft sleeves and seal sleeves, case and impeller wear rings, throat and line bushings, spacers and collars, and the flat work around the pump, such as adapter plates, regulator plates, mounting plates and covers. Round parts are turned, plates are milled, and a sleeve or bushing whose print calls for a ground diameter or bore goes through precision grinding on the same order.

Parts are made to the dimensions, material and finish on your print. A plain bushing that carries a bearing load rather than protecting a shaft is covered on custom bushings.

Shaft sleeves in a pump parts order

A shaft sleeve is the replaceable skin on a pump shaft. Writing in Pumps & Systems, Jim Elsey gives its main job as protecting the shaft “from wear caused by packing abrasion, followed closely by prevention of erosion and corrosion,” and describes the sleeve as the part designed to be replaced (source 1). In some horizontal split-case pumps the sleeve also locates the impeller along the shaft (source 1). A sleeve is quoted as a single piece or as a family of similar sizes. Pump shaft sleeves has the full page on packing and seal sleeves.

The print for a sleeve carries the bore and its fit to the shaft, the OD and its finish under the packing or seal, the length and any shoulder that locates it, keyways or set-screw holes, an O-ring groove in the bore if there is one, runout between OD and bore, and the material. Position, perpendicularity and runout callouts are quoted from the print. With no drawing, a new sample part can be sent instead: it is measured, drawn and quoted through reverse engineering, with the CAD work quoted as its own line. The sample ships back with the parts. A family of similar sleeves, ten sizes in the same material for example, is quoted together with each size at its own quantity. A shop that rebuilds pumps and orders the same sleeves, rings and bushings year after year can start on wear parts for pump and motor repair shops, which covers reorders and blanket orders. Reorders at the same revision: send the last quote or PO number and it’s requoted. Price, release schedule and lead time per release are set in the quote.

Rings at the impeller: clearance and galling

Suction-side wear rings limit the flow from the higher-pressure discharge side of the impeller back to the suction side. Eugene Vogel of EASA writes in Pumps & Systems that excessive clearance at these rings can cause “a volumetric loss of efficiency,” and that the values in the API Standard 610 chart of minimum running clearances are very close to the general guidelines for new rings (source 2). The clearance on your drawing is what the ring is quoted to. MI CNC Parts does not set the fit or the running clearance.

Writing in Pumps & Systems, Robert Aronen says that with metal rings “an inherent risk of seizure exists,” and that nonmetallic materials “do not seize in the same manner as metal parts” (source 3). He quotes API 610 as asking for a Brinell hardness difference of at least 50 between mating rings unless both are at least 400, so the print for a metal pair should carry the hardness of each ring, or name a nonmetallic ring. Galling is a form of wear caused by adhesion between sliding surfaces (source 4). Put the hardness or condition of each ring on the print and it is quoted as drawn; if the hardness has to be checked, say so, and that can be arranged and quoted. Case and impeller rings have their own page, wear rings.

Stainless, bronze, PEEK or G10: which material for a pump part?

316 stainless is the usual step up from 304 where chlorides are present: its molybdenum gives greater resistance to localized attack by chlorides (source 5), and 304 is commonly replaced by 316 when it is too sensitive to pitting or crevice corrosion (source 6). 17-4 PH is a martensitic precipitation-hardened grade used where high strength, hardness and corrosion resistance are required (source 7), so it is the one to name when a sleeve or ring needs hardness. Bronze has low friction against dissimilar metals and resists salt water corrosion, and it is still widely used for bearings and bushings (source 8). PEEK is highly resistant to attack by both organic and aqueous environments and is used for bearings, pumps and compressor plate valves, with some grades useful to 250 °C (source 9); PEEK parts covers the grade. G10 is a glass-epoxy laminate favored for low moisture absorption and a high level of electrical insulation (source 10), so a print can name it for an insulating plate or spacer. Anodized 6061 covers plates and housings where the fluid allows aluminum. Other alloys and plastics quoted on request. Name the grade on the print.

Can a small first lot come before the production run?

Yes. A handful of pieces can come first to check fit, then the production quantity follows on the same print. Ask for more than one quantity, such as 1, 25 and 100, and the quote shows each. Small-batch CNC machining covers how low quantities are quoted. Name the critical dimensions on the print.

Quotes come back in 24-48 hours. Rush: 1-2 weeks. Standard: 4-6 weeks (typical). Extended: 6-8 weeks, for jobs that aren't time-sensitive. A first lot on Rush and the production run on Standard can sit on the same quote. Rush is quoted at a premium. Rush 1-2 weeks applies to machined parts with no secondary operations. Heat treat, grinding, EDM and finishing add time, and the quote gives the real date. Lead time starts at order approval. Put your need date in the part description and the quote answers it.

What comes with the parts, and what does not?

Every part is inspected against the print before it ships. Vendor setup takes a day: W-9, NDA, net terms available, and one contact from quote to delivery.

No C of C or material certifications ship with parts by default. If your PO needs them, say so before the quote. Inspection reports on critical dimensions aren’t included by default. If you need one, ask when you place the order.

Sources

All accessed 4 October 2026. Where a figure here differs from your print, the print governs.

1. Jim Elsey, “Solid Shaft Designs & Cartridge Seals,” Pumps & Systems, 17 February 2016: pumpsandsystems.com/solid-shaft-designs-cartridge-seals (what a shaft sleeve is for; designed to be replaceable; locates the impeller in some horizontal split-case pumps).

2. Eugene Vogel, EASA, “Wear Ring Clearance for Centrifugal Pumps,” Pumps & Systems, 7 June 2019: pumpsandsystems.com/wear-ring-clearance-centrifugal-pumps (what suction-side wear rings do; excessive clearance and volumetric efficiency; API 610 chart values against general guidelines for new rings).

3. Robert Aronen, Boulden International, “The Power of Wear Rings Part Three: Safety,” Pumps & Systems, May 2011 issue, posted 17 December 2011, pumpsandsystems.com/power-wear-rings-part-three-safety (risk of seizure with metal rings; nonmetallic materials; API 610 hardness difference). Cited as plain text because the byline names the author’s company.

4. Wikipedia, “Galling”: en.wikipedia.org/wiki/Galling (galling as wear caused by adhesion between sliding surfaces).

5. Wikipedia, “SAE 316L stainless steel”: en.wikipedia.org/wiki/SAE_316L_stainless_steel (molybdenum gives greater resistance than 304 to localized attack by chlorides).

6. Wikipedia, “SAE 304 stainless steel”: en.wikipedia.org/wiki/SAE_304_stainless_steel (304 commonly replaced by 316 when too sensitive to pitting or crevice corrosion by chlorides).

7. Wikipedia, “17-4 stainless steel”: en.wikipedia.org/wiki/17-4_stainless_steel (martensitic precipitation-hardened grade; used where high strength, hardness and corrosion resistance are required).

8. Wikipedia, “Bronze”: en.wikipedia.org/wiki/Bronze (low friction against dissimilar metals; salt water corrosion; still widely used for bearings and bushings).

9. Wikipedia, “Polyether ether ketone”: en.wikipedia.org/wiki/Polyether_ether_ketone (resistance to organic and aqueous environments; bearings, pumps and compressor plate valves; operating temperature up to 250 °C for some grades).

10. Wikipedia, “G-10 (material)”: en.wikipedia.org/wiki/G-10_(material) (glass cloth in epoxy; low moisture absorption; electrical insulation).