ARO EXP Metallic Diaphragm Pumps
Spare Parts for ARO EXP Metallic Air-Operated Diaphragm Pumps
Product Summary
Genuine OEM spare parts for ARO EXP Metallic pumps: metallic air-operated double-diaphragm (AODD) pumps in aluminium, cast iron, stainless steel and Hastelloy. Service kits, diaphragms, balls and seats for each size are listed below with ARO part numbers from the operator’s manuals, so you can match the wetted materials on your pump.
Spare Parts List
✓ Tick the parts you need. Codes are as printed in the ARO operator’s manuals. Diaphragm, ball and seat materials are set by the model code, and fluid kit suffixes (-XX / -XXX) follow your model code, so pick your model in the form below. Not sure? Add a photo of the nameplate and we’ll match the parts for you.
| Select | Part (as printed by ARO) | Part number & reference |
|---|---|---|
| 1" EXP Metallic (PD10A, PD10R, PD10S) | ||
| Air Section Service Kit | Part no. 637397 · Fits PD10A, PD10R, PD10S | |
| Fluid Section Service Kit (with seats) | Part no. 637401-XXX · Fits PD10A, PD10R, PD10S | |
| Fluid Section Service Kit (without seats) | Part no. 637401-XX · Fits PD10A, PD10R, PD10S | |
| Major Air Valve Assembly | Part no. 637395-X · Fits PD10A, PD10R, PD10S | |
| Diaphragm – Santoprene | Part no. 96267-A · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Diaphragm – Hytrel | Part no. 96267-C · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Diaphragm – Nitrile | Part no. 96328-2 · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Diaphragm – Long Life PTFE | Part no. 96146-L · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Diaphragm – Medical Grade Santoprene | Part no. 96267-M · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Diaphragm – PTFE | Part no. 96146-T · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Diaphragm – Viton | Part no. 95989-3 · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Backup Diaphragm – Santoprene (for PTFE / Long Life PTFE) | Part no. 96145-A · Qty 2 · Fits PD10A, PD10R, PD10S | |
| Ball – Santoprene | Part no. 93278-A · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Ball – Hytrel | Part no. 93278-C · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Ball – Nitrile | Part no. 93278-2 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Ball – Stainless Steel | Part no. 92408 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Ball – PTFE | Part no. 93278-4 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Ball – Viton | Part no. 93278-3 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Santoprene | Part no. 96152-A · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Hytrel | Part no. 96152-C · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Carbon Steel | Part no. 96158 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Aluminium | Part no. 96156 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Nitrile | Part no. 96152-G · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Hard Stainless Steel | Part no. 94706 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Hastelloy-C | Part no. 95836 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| Seat – Stainless Steel | Part no. 96151 · Qty 4 · Fits PD10A, PD10R, PD10S | |
| 1-1/2" EXP Metallic (PD15A, PD15R, PD15S) | ||
| Air Section Service Kit | Part no. 637389 · Fits PD15A, PD15R, PD15S | |
| Fluid Section Service Kit (with seats) | Part no. 637375-XXX · Fits PD15A, PD15R, PD15S | |
| Fluid Section Service Kit (without seats) | Part no. 637375-XX · Fits PD15A, PD15R, PD15S | |
| Major Air Valve Assembly | Part no. 637390-X · Fits PD15A, PD15R, PD15S | |
| Diaphragm – Santoprene | Part no. 96166-A · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Diaphragm – Hytrel | Part no. 96166-C · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Diaphragm – Nitrile | Part no. 96329-2 · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Diaphragm – Long Life PTFE | Part no. 96165-L · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Diaphragm – Medical Grade Santoprene | Part no. 96166-M · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Diaphragm – PTFE | Part no. 96165-T · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Diaphragm – Viton | Part no. 95820-3 · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Backup Diaphragm – Santoprene (for PTFE / Long Life PTFE) | Part no. 96164-A · Qty 2 · Fits PD15A, PD15R, PD15S | |
| Ball – Santoprene | Part no. 95826-A · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Ball – Hytrel | Part no. 95826-C · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Ball – Nitrile | Part no. 95826-2 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Ball – Stainless Steel | Part no. 95878 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Ball – PTFE | Part no. 95826-4 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Ball – Viton | Part no. 95826-3 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Santoprene | Part no. 95825-A · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Hytrel | Part no. 95825-C · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Carbon Steel | Part no. 95893 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Aluminium | Part no. 95892 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Nitrile | Part no. 95825-G · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Hard Stainless Steel | Part no. 95891 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Hastelloy-C | Part no. 95947 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| Seat – Stainless Steel | Part no. 95877 · Qty 4 · Fits PD15A, PD15R, PD15S | |
| 2" EXP Metallic (PD20A, PD20S, PD20R) | ||
| Air Section Service Kit (PD20A, PD20S) | Part no. 637421 · Fits PD20A, PD20S | |
| Fluid Section Service Kit (with seats) | Part no. 637309-XXX · Fits PD20A, PD20S, PD20R | |
| Fluid Section Service Kit (without seats) | Part no. 637309-XX · Fits PD20A, PD20S, PD20R | |
| Major Air Valve Assembly (PD20A, PD20S) | Part no. 637374-X · Fits PD20A, PD20S | |
| Air Section Service Kit (PD20R) | Part no. 637369 · Fits PD20R | |
| Major Air Valve Assembly (PD20R) | Part no. 637374 · Fits PD20R | |
| Diaphragm – Santoprene | Part no. 94329-A · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – Santoprene (also the backup diaphragm for PTFE / Long Life PTFE) | Part no. 94330-A · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – Hytrel | Part no. 94329-C · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – Nitrile | Part no. 96330-2 · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – Long Life PTFE | Part no. 94355-L · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – Medical Grade Santoprene | Part no. 94329-M · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – PTFE | Part no. 94355-T · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Diaphragm – Viton | Part no. 95344 · Qty 2 · Fits PD20A, PD20S, PD20R | |
| Ball – Santoprene | Part no. 93358-A · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Ball – Hytrel | Part no. 93358-C · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Ball – Nitrile | Part no. 93358-2 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Ball – Stainless Steel | Part no. 94805 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Ball – PTFE | Part no. 93358-4 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Ball – Viton | Part no. 93358-3 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Santoprene | Part no. 94328-A · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Hytrel | Part no. 94328-C · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Carbon Steel | Part no. 95677 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Aluminium | Part no. 95673 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Nitrile | Part no. 94328-G · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Hard Stainless Steel | Part no. 94354 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – PVDF | Part no. 94477-K · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Hastelloy-C | Part no. 95639 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| Seat – Stainless Steel | Part no. 94353 · Qty 4 · Fits PD20A, PD20S, PD20R | |
| 3" EXP Metallic (PD30A, PD30S, PD30R) | ||
| Air Section Service Kit (PD30A, PD30S) | Part no. 637421 · Fits PD30A, PD30S | |
| Fluid Section Service Kit (with seats) | Part no. 637303-XXX · Fits PD30A, PD30S, PD30R | |
| Fluid Section Service Kit (without seats) | Part no. 637303-XX · Fits PD30A, PD30S, PD30R | |
| Major Air Valve Assembly | Part no. 637374-X · Fits PD30A, PD30S, PD30R | |
| Air Section Service Kit (PD30R) | Part no. 637369 · Fits PD30R | |
| Diaphragm – Santoprene | Part no. 94091-A · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Diaphragm – Santoprene (also the backup diaphragm for PTFE / Long Life PTFE) | Part no. 94110-A · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Diaphragm – Hytrel | Part no. 94091-C · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Diaphragm – Nitrile | Part no. 96016-2 · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Diaphragm – Long Life PTFE | Part no. 94090-L · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Diaphragm – PTFE | Part no. 94090-T · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Diaphragm – Viton | Part no. 95345 · Qty 2 · Fits PD30A, PD30S, PD30R | |
| Ball – Santoprene | Part no. 94103-A · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Ball – Hytrel | Part no. 94103-C · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Ball – Nitrile | Part no. 94103-G · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Ball – PTFE | Part no. 94103-T · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Ball – Viton | Part no. 94103-V · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Santoprene | Part no. 94104-A · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Hytrel | Part no. 94104-C · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Carbon Steel | Part no. 95678 · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Aluminium | Part no. 95674 · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Nitrile | Part no. 94104-G · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Hard Stainless Steel | Part no. 94114 · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – PVDF | Part no. 94621-K · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Hastelloy-C | Part no. 94939 · Qty 4 · Fits PD30A, PD30S, PD30R | |
| Seat – Stainless Steel | Part no. 94113 · Qty 4 · Fits PD30A, PD30S, PD30R | |
How we confirm the exact part: Part numbers on this page are as printed in the current ARO operator’s manual for each size. The materials, thread type (NPT or BSP) and options are coded in the full model number on the nameplate (for example PD20A-BAP-STT-B), and older revisions can use different parts, so send the full model number or a nameplate photo and we’ll confirm the right part before we quote.
Service Intervals & When to Replace
- Diaphragms, balls and seats are the main wear parts. ARO lists them as “Smart Parts” to keep on hand with the service kits for a fast repair.
- Fluid section service kit: renews the diaphragms, balls (and seats where the kit includes them) plus the fluid-side O-rings and seals. Fit it whenever a diaphragm fails or flow drops off.
- Air section service kit: renews the air motor seals and wear parts. Fit it if the pump blows air, stalls or short-strokes.
- Air supply: filter the air to 50 microns and never exceed the maximum air inlet pressure on the nameplate. Most applications need no air-line lubrication.
- Shutdown: flush the pump with a suitable solvent if the product can set up while idle, and keep a service log as part of a preventive maintenance program.
Models
This page covers ARO EXP Metallic pumps in 1", 1-1/2", 2", 3". The full model code (for example PD10A-BAS-STT) is on the pump nameplate and sets the materials and kit suffixes.
Models & Key Specifications
| Model | Size | Max flow | Max air pressure | Max particle size | Manual |
|---|---|---|---|---|---|
| PD10A, PD10R, PD10S | 1" | 52.2 gpm (197.6 lpm) | 120 psig (8.3 bar) | 1/8” dia. (3.3 mm) | PX10X-XXX-XXX-AXXX |
| PD15A, PD15R, PD15S | 1-1/2" | 123 gpm (465.6 lpm) | 120 psig (8.3 bar) | 1/4” dia. (6.4 mm) | PX15X-XXX-XXX-AXXX |
| PD20A, PD20S | 2" | 172 gpm (651 lpm) | 120 psig (8.3 bar) | 1/4” dia. (6.4 mm) | PX20X-XXX-XXX-BXXX |
| PD20R | 2" | 172 gpm (651 lpm) | 120 psig (8.3 bar) | 1/4” dia. (6.4 mm) | PX20R-XXX-XXX-BXXX |
| PD30A, PD30S | 3" | 237 gpm (897 lpm) | 120 psig (8.3 bar) | 3/8” dia (9.5 mm) | PX30X-XXX-XXX-CXXX |
| PD30R | 3" | 237 gpm (897 lpm) | 120 psig (8.3 bar) | 3/8” dia. (9.5 mm) | PX30R-XXX-XXX-CXXX |
Figures from the ARO operator’s manuals (flooded inlet where stated). Typical uses: mining, chemical transfer, wastewater, paints and general industrial duty.
Troubleshooting
Product discharged from the air exhaust
Likely cause: A ruptured diaphragm, or a loose diaphragm washer, nut or screw. Action: Replace the diaphragms (the fluid section service kit includes them) and tighten the diaphragm hardware to the manual torque.
Air bubbles in the product discharge
Likely cause: A leak in the suction plumbing, worn O-rings between the inlet manifold and fluid caps, or loose diaphragm hardware. Action: Check the suction connections, replace the manifold O-rings and tighten the diaphragm washer, nut or screw.
Low output volume, erratic flow or no flow
Likely cause: Low air supply, a blocked or kinked outlet hose, a collapsed or undersized suction hose (cavitation), leaking inlet joints, or a solid object lodged in the diaphragm chamber or seat area. Action: Check the air supply and hoses, use a non-collapsing suction hose at least the size of the pump inlet, make the inlet joints airtight, and inspect the balls and seats for damage or debris.
Air motor blows air or stalls
Likely cause: Worn major valve seals, pilot valve parts or check valve, or a restriction in the valve or exhaust. Action: Fit the air section service kit (renews the air motor seals and wear parts) and clear the exhaust and muffler.
Request for Quotation
Selected Parts:
- No parts selected
Not sure which parts? Just send a photo of the nameplate or part below.
ARO EXP Metallic spare parts: frequently asked questions
Tap a question to see the answer.
What spare parts are listed for ARO EXP Metallic pumps?
Each size from 1" to 3" has its own list of air and fluid section service kits, diaphragms, balls and seats, with ARO part numbers from the operator’s manuals. Diaphragms are listed in Hytrel, Long Life PTFE, Medical Grade Santoprene, Nitrile, PTFE, Santoprene and Viton. See all ARO spare parts by series.
Which fluid section service kit fits my EXP Metallic pump?
The kit number changes with size, and its suffix follows the ball and diaphragm materials in your model code. On the 1" pump, for example, it is 637401-XXX. Tick the kit and add your full model number or a nameplate photo, and we’ll confirm the exact suffix before quoting.
Why is product coming out of the air exhaust?
The troubleshooting guide points to a ruptured diaphragm or a loose diaphragm washer, nut or screw. Replace the diaphragms, which are included in the fluid section service kit, and tighten the diaphragm hardware. Diaphragms for each wetted material are listed in the table above.
What should I do if the air motor blows air or stalls?
Worn major valve seals, pilot parts or a restricted exhaust are the usual causes. The air section service kit renews the air motor seals and wear parts; on the 1" pump it is part 637397. Clear the exhaust and muffler as well.