Aftermarket Parts · ASME B73.1
Durco Pump Parts — Mark 3 Aftermarket List by Group
YSM manufactures aftermarket casings, reverse-vane impellers, rear cover plates, bearing housing adapters, bearing housings, bearing carriers, feet, shafts and hook sleeves for pumps built to the Durco Mark 3 pattern under ASME B73.1. The tables list each part by size designation and Group with the YSM reference number and the OEM part number it corresponds to. The OEM number identifies the part to be matched; the fit is confirmed against your pump nameplate and drawing before an order is accepted.
Identify the installed pump first
The nameplate carries the size designation with its Group prefix (for example 2K3×2-13), the serial number and, on the parts list supplied with the pump, the POS number of each part. Send the size and serial number with the part name or POS number; if the pump is a Mark 3A, say so, because the power-end parts differ from the earlier generation. The D Mark III series page describes the Groups and sizes; the D Mark III vs Durco Mark 3 interchange guide explains what ASME B73.1 fixes and what YSM confirms from drawings.
| Group | Prefix | Pump sizes on this page |
|---|---|---|
| Group 1 | 1K | 1.5×1-6, 3×1.5-6, 3×2-6, 1.5×1-8, 3×1.5-8 and the 1.5×1LF-4 and 1.5×1LF-8 low-flow sizes |
| Group 2 | 2K | 8 in, 10 in and 13 in sizes from 3×2-8 to 6×4-13A, including the H and HH high-head hydraulics and the 2×1LF-10 and 3×1.5LF-13 low-flow sizes |
| Group 3 | 3K | 8×6-14A, 10×8-14, 6×4-16, 8×6-16, 8×6-16A, 10×8-16, 10×8-16H, 10×8-17 |
The bearing housing and bearing carrier references on this page are for the Mark IIIA power end, as stated on the source sheets; say which generation the nameplate shows.
Parts by POS number and material
A YSM reference ends in the POS number of the part: 100 casing, 3 impeller, 106 rear cover, 108 adapter, 119 bearing housing, 201 bearing carrier, 109 foot, 105 shaft, 177 hook sleeve. The letters before it identify the size designation or Group, so the casing and impeller of one size share a prefix (DAU100 and DAU3 are the 2K4×3-13 casing and impeller).
| Part | POS no. | YSM ref. suffix | Materials offered | Confirmed before order |
|---|---|---|---|---|
| Casing | 100 | 100 | WCB carbon steel, CF8M (316SS), CF3M (316L), CD4MCu duplex, super duplex, CN7M (Alloy 20), Monel, Nickel, Inconel, Hastelloy B and C, Titanium, Zirconium alloy | Size designation, flange rating and face, drain and gauge tappings |
| Reverse-vane impeller | 103 | 3 | CF8M, CF3M, CD4MCu, super duplex, CN7M, Monel, Nickel, Inconel, Hastelloy B and C, Titanium, Zirconium alloy | Size designation, current trim diameter or duty point, hub thread from the shaft |
| Rear cover plate | 106 | 106 (variants B, D, E) | WCB, CF8M, CF3M, CD4MCu, super duplex, CN7M, Monel, Nickel, Inconel, Hastelloy, Titanium | Group and impeller diameter; seal chamber type (CBS, CBL, FMS, FML or packed box); gland bolting |
| Bearing housing adapter | 108 | 108 | Ductile iron | Group and impeller diameter |
| Bearing housing | 119 | 119 | Ductile iron | Group; Mark 3 or Mark 3A; oil-lubricated or oil-mist |
| Bearing carrier | 201 | 201 | Per YSM drawing, stated at quotation | Group; bearing arrangement fitted |
| Bearing housing foot | 109 | 109 | Per YSM drawing, stated at quotation | Group and impeller diameter |
| Shaft | 105 | 105, 105S | SAE 4140, 316SS | Whether a hook sleeve is fitted (selects the 105 or 105S version); coupling-end diameter and keyway; impeller thread |
| Hook sleeve | 177 | 177 | Wet-end alloy of the pump | Group; seal setting dimension |
FMI-type seal chambers and jacketed rear covers are not offered. Alloys not listed for a part are quoted on request. Higher alloys are cast on the same patterns as the CF8M part, so the dimensions do not change with the grade. Material certificates, spectrometer analysis and a dimensional inspection report can be supplied with the order.
Casings and impellers by size designation
Casing and impeller references are specific to the size designation. The impeller reference is the reverse-vane impeller at standard diameter; state the trim diameter, or the duty point, if the installed impeller has been cut down.
| Pump size | Casing · YSM ref. | Casing · OEM no. | Impeller · YSM ref. | Impeller · OEM no. |
|---|---|---|---|---|
| 1K1.5×1LF-4 | DYA100 | BY40035AI | DYA3 | MY55565A40 |
| 1K1.5×1-6 | DKA100 | DY50772 | DKA3 | MY50798A62 |
| 1K3×1.5-6 | DKC100 | DY50794A | DKC3 | MY50746A62 |
| 1K3×2-6 | DKE100 | DY50733A | DKE3 | MY50723A62 |
| 1K1.5×1LF-8 | DYB100 | BY40035AU | DYB3 | MY55575A82 |
| 1K1.5×1-8 | DKB100 | DY52981A | DKB3 | MY50754A82 |
| 1K3×1.5-8 | DKD100 | DY50659A | DKD3 | MY50656A82 |
LF marks the low-flow casings.
| Pump size | Casing · YSM ref. | Casing · OEM no. | Impeller · YSM ref. | Impeller · OEM no. |
|---|---|---|---|---|
| 2K3×2-8 | DAF100 | DY46070A | DAF3 | MY46066A82 |
| 2K4×3-8 | DAG100 | DY46161A | DAG3 | MY46157A82 |
| 2K2×1LF-10 | DYC100 | BY40035AV | DYC3 | MY55574A100 |
| 2K2×1-10A | DAH100 | DY46950A | DAH3 | MY46952AA100 |
| 3×1.5-10 | DAJ100 | CY22118A | DAJ3 | MY36861A100 |
| 2K3×1.5-10A | DAK100 | DY50995A | DAK3 | MY51157A100 |
| 3×2-10 | DAL100 | CY21802A | DAL3 | MY36862A100 |
| 2K3×2-10A | DAM100 | DY51040A | DAM3 | MY51049A100 |
| 2K4×3-10 | DAN100 | CY22235A | DAN3 | MY35641AA100 |
| 2K4×3-10H | DAP100 | CY22385A | DAP3 | MY36877A100 |
| 2K6×4-10 | DAQ100 | DY47208A | DAQ3 | MY47210AA100 |
| 2K6×4-10H | DAR100 | DY51022A | DAR3 | MY50824A100 |
| 2K3×1.5LF-13 | DYD100 | BY40035AW | DYD3 | MY55573A130 |
| 2K3×1.5-13 | DAS100 | CY21853A | DAS3 | MY36649AA130 |
| 2K3×2-13 | DAT100 | CY22312A | DAT3 | MY49112A130 |
| 2K4×3-13 | DAU100 | CY22344A | DAU3 | MY36847AA130 |
| 2K4×3-13HH | DAV100 | DY50172A | DAV3 | MY50171AA130 |
| 2K6×4-13A | DAW100 | DY33074A | DAW3 | MY36846AA130 |
A, H and HH mark the alternative hydraulics of a size; use the exact designation from the nameplate. The 3×1.5-10 and 3×2-10 rows are the sizes listed without the A suffix on the source sheet.
| Pump size | Casing · YSM ref. | Casing · OEM no. | Impeller · YSM ref. | Impeller · OEM no. |
|---|---|---|---|---|
| 3K8×6-14A | DNA100 | DY32218AA | DNA3 | MY40103AA140 |
| 3K10×8-14 | DNB100 | DY48876AA | DNB3 | MY48879A140 |
| 3K6×4-16 | DNE100 | DY51013A | DNE3 | MY51017A160 |
| 8×6-16 | DNF100 | DY30546A | DNF3 | MY39056AA160 |
| 3K8×6-16A | DNG100 | DY48890AA | DNG3 | MY48888A160 |
| 3K10×8-16 | DNC100 | DY48899AA | DNC3 | MY48902A160 |
| 3K10×8-16H | DND100 | DY48925AA | DND3 | MY48928A160 |
| 3K10×8-17 | DNH100 | CY29134A | DNH3 | MY38068A170 |
Both 8×6-16 casings are listed; use the designation on the nameplate.
Rear cover plates
The rear cover is selected by Group and impeller diameter, not by pump size. Tell us which chamber the pump runs today (CBS, CBL, FMS, FML or a packed box) and the gland bolting, and we confirm the variant before quoting.
| Frame / impeller diameter | Standard cover | Variant B | Variant D | Variant E |
|---|---|---|---|---|
| Group 1 (listed on the source sheet against 1K1.5×1LF-4) | DKA106 OEM CY22418A | DKA106B OEM CY52018A | DKA106D OEM CY54131A | DKA106E OEM CY54132A |
| Group 2 · 8 in | DAF106 OEM CY46072A | DAF106B OEM CY52024A | DAF106D OEM CY53432A | DAF106E OEM CY53433A |
| Group 2 · 10 in | DAH106 OEM CY21805A | DAH106B OEM DY52026A | DAH106D OEM DY53439A | DAH106E OEM DY53440A |
| Group 2 · 13 in | DAS106 OEM DY21855A | DAS106B OEM DY52028A | DAS106D OEM DY53442A | DAS106E OEM DY53443A |
| Group 3 · 14 in | DNA106 OEM DY28284AA | DNA106B OEM DY52030A | DNA106D OEM DY53499A | DNA106E OEM DY53501A |
| Group 3 · 16 in | DNE106 OEM DY27457AA | DNE106B OEM DY52032A | DNE106D OEM DY53502A | DNE106E OEM DY53504A |
| Group 3 · 17 in | DNH106 OEM DY29137A | DNH106B OEM DY52034A | DNH106D OEM DY55261A | DNH106E OEM DY55258A |
The standard reference is the rear cover for the packed stuffing box. Variants B, D and E are the seal chamber designs; the chamber type of each is confirmed at quotation.
Power-end parts, shafts and sleeves
Power-end parts are selected by Group, adapters and feet also by impeller diameter. For shafts, state whether the pump runs a hook sleeve or a solid shaft, and send the coupling-end diameter and keyway if the coupling is to be reused. Bearings, oil seals and labyrinth isolators are bought-out items and can be included with the order.
| Part | Frame / group | YSM ref. | OEM no. |
|---|---|---|---|
| Bearing housing adapter (POS 108) | Mark 3 Group 2 8″ | DAF108 | DY46074AAP |
| Bearing housing adapter (POS 108) | Mark 3 Group 2 10″ | DAH108 | DY21806ACP |
| Bearing housing adapter (POS 108) | Mark 3 Group 2 13″ | DAS108 | DY21857ABP |
| Bearing housing adapter (POS 108) | Mark 3 Group 3 14″ | DNA108 | DY28285ACP |
| Bearing housing adapter (POS 108) | Mark 3 Group 3 16″ | DNE108 | DY27463ACP |
| Bearing housing (POS 119) | Mark IIIA Group 1 | D1119 | DY55721B |
| Bearing housing (POS 119) | Mark IIIA Group 2 | D2119 | DY55718A |
| Bearing housing (POS 119) | Mark IIIA Group 3 | D3119 | DY55723A |
| Bearing carrier (POS 201) | Mark IIIA Group 1 | D1201 | CY55739AP |
| Bearing carrier (POS 201) | Mark IIIA Group 2 | D2201 | CY55742AP |
| Bearing carrier (POS 201) | Mark IIIA Group 3 | D3201 | DY55743AP |
| Bearing housing foot (POS 109) | 6″ & 8″ | DKA109 | CY55732AK |
| Bearing housing foot (POS 109) | 3×1.5-8 | DYD109 | CY55733AK |
| Bearing housing foot (POS 109) | 8″ & 10″ small | DYF109 | CY55736AK |
| Bearing housing foot (POS 109) | 10″ large & 13″ | DYS109 | CY55737AK |
| Bearing housing foot (POS 109) | Group 3 | DNA109 | CY55738AK |
| Shaft (POS 105), 105S version | Mark 3 Group 1 | D1105S | CY50686A |
| Shaft (POS 105), 105 version | Mark 3 Group 1 | D1105 | CY50683A |
| Shaft (POS 105), 105S version | Mark 3 Group 2 | D2105S | CY32768B |
| Shaft (POS 105), 105 version | Mark 3 Group 2 | D2105 | CY21361BA |
| Shaft (POS 105), 105S version | Mark 3 Group 3 | D3105S | CY50467A |
| Shaft (POS 105), 105 version | Mark 3 Group 3 | D3105 | CY50463A |
| Hook sleeve (POS 177) | Mark 3 Group 1 | D1177 | AY50691A |
| Hook sleeve (POS 177) | Mark 3 Group 2 | D2177 | AY38913AA |
| Hook sleeve (POS 177) | Mark 3 Group 3 | D3177 | BY39477A |
Bearing housing and bearing carrier references are for the Mark IIIA power end. Each Group has two shaft references on the source sheet, 105 and 105S. Which one fits depends on the sleeve arrangement of the installed pump and is confirmed at quotation.
What we confirm before an order
From your side
- Nameplate photo: size designation with Group prefix, serial number, Mark 3 or Mark 3A
- The part and quantity, with the POS or OEM part number if the parts list is available
- Material of the installed part, or the liquid, concentration and temperature if the material is to be reviewed
- For impellers: trim diameter or the duty point (flow and head)
- For rear covers: seal chamber type and gland bolting
From YSM
- The YSM reference matched to your nameplate data, with the interfaces checked listed in the quotation
- Material grade and the documents to be supplied: material certificate, spectrometer analysis, dimensional inspection report, balance report for impellers, hydrostatic test for casings
- Inspection scope, including factory witness or third-party inspection (SGS, BV, TÜV) where required
- Packing and Incoterms as agreed in the quotation
Anything unknown can be stated as unknown; a marked gap is reviewed, a silent one is not. The pre-replacement checklist lists the same items in order, and the OEM number finder on the parts hub searches every reference on this page by OEM number.
Frequently Asked Questions
Do you supply Durco spares and aftermarket Durco pump parts?
Yes. YSM supplies non-OEM aftermarket Durco Mark 3 pattern parts — casing, reverse-vane impeller, rear cover, adapter, bearing housing, bearing carrier, foot, shaft and hook sleeve — in the materials listed above. Parts are dimensionally interchangeable at the same size designation, group and configuration, confirmed against the installed pump drawing before quotation.
Are these Flowserve or Durco parts?
No. They are aftermarket parts manufactured by YSM to the Durco Mark 3 pattern. OEM part numbers appear in the tables only to identify which part a YSM reference corresponds to. YSM is not affiliated with Flowserve.
How do you confirm that a part will fit my pump?
From the nameplate: the size designation with its Group prefix and the serial number select the row in the tables. We then confirm the interfaces that matter for that part (casing register and stud pattern, impeller hub and thread, rear cover bore and gland bolting, shaft coupling end) against our drawings and, where you can supply them, your drawing or the removed part. The quotation lists what was checked.
My pump is a Mark 3A. Do the same parts apply?
Wet-end parts are selected by size designation in the same way. The bearing housing and bearing carrier references in the tables are for the Mark IIIA power end; tell us which generation the nameplate shows and we confirm the power-end parts before quoting.
Do you supply the reverse-vane impeller?
Yes. The impeller references in the tables are reverse-vane impellers at standard diameter. State the trim diameter marked on the impeller or nameplate, or send the duty point (flow and head), and we select the diameter. Every impeller is dynamically balanced before shipment.
Which materials can you supply?
Wet-end parts in CF8M (316SS), CF3M (316L), CD4MCu duplex, super duplex, CN7M (Alloy 20), Monel, Nickel, Inconel, Hastelloy B and C, Titanium and Zirconium alloy; casings also in WCB carbon steel. Bearing housings and adapters in ductile iron, shafts in SAE 4140 or 316SS with hook sleeves in the wet-end alloy. Alloy verification by spectrometer is standard; material certificates are supplied on request.
Can you supply a size that is not in the tables?
The tables list the sizes that have a YSM reference today. For another Mark 3-pattern size send the nameplate and, if possible, a drawing or the removed part; the part is then quoted from a reviewed drawing. Obsolete or undocumented parts can be reverse engineered from the removed part. Selected numbers also have a page of their own in the pump part number lookup, with the part, its size and the other positions for that size.
Send the Nameplate or the POS Number. Get the Matching Parts List.
Send the pump nameplate, the part and quantity, and the POS or OEM part number if you have it. The YSM references and the interfaces we check are confirmed before order.
Trademarks
Durco and Mark 3 are trademarks of Flowserve Corporation or its subsidiaries and are used on this page only to identify the pump pattern that the parts listed are made to fit. YSM Pumps (Jinan Yingsiman Machinery Co., Ltd.) is an independent manufacturer and is not affiliated with, authorised by, sponsored by or endorsed by Flowserve. All parts listed are non-OEM parts manufactured by YSM.