Sandpiper S20 Non-Metallic Pumps
Spare Parts for Sandpiper S20 2" Non-Metallic Air-Operated Double Diaphragm Pumps
Product Summary
Genuine OEM spare parts for the Sandpiper S20 2" non-metallic air-operated double diaphragm (AODD) pump, moulded in polypropylene, PVDF or conductive polypropylene for acids, caustic, hypochlorite and other corrosive chemicals in Australian water treatment, mining reagent and process plants. Wet End and Air End Kits, diaphragms, PTFE overlays, check balls, PVDF or polypropylene seats and the air valve and pilot valve parts are all listed in the Sandpiper S20 Non-Metallic Design Level 3 parts list, so tick what you need and we’ll match them to your nameplate, such as S20B3P1PPUS000.
Spare Parts List
✓ Tick the parts you need. Sandpiper S20 Non-Metallic parts are matched to the pump's model code (wetted, diaphragm/valve and non-wetted material codes), so the full model number on your nameplate is all we need to get them right. Not sure which items? Add a photo of the nameplate and we’ll work it out for you.
| Select | Wear / Service Item | Function & when to replace |
|---|---|---|
| Common Service Kits | ||
| Wet End Kit | Sandpiper’s S20 non-metallic wet end set: two diaphragms (plus PTFE overlays where fitted), four check balls and the PTFE check valve and manifold seals. The usual kit to fit when a diaphragm has split or the balls are worn. | |
| Air End Kit (476.253.000 / 476.253.559) | Seals, O-rings, gaskets, retaining rings, the air valve sleeve and spool set and the pilot valve assembly. On the S20 it is the rebuild for a pump that stalls, short-strokes or bleeds air; the complete air valve body is ordered separately. | |
| Diaphragm (item 17) | Two per pump, fitted with the convolutions towards the centre. Replace both at once if either is cracked, stretched at the bolt holes or attacked by the product, or if fluid shows at the exhaust. | |
| Check Ball (item 3) | Four balls, two per outer chamber, that seal the S20’s inlet and outlet valves on alternate strokes. Replace when they are flattened, undersized, chewed or swollen and the pump loses prime or flow. | |
| Check Valve Seat (item 38) | The seat each ball closes against, in PVDF or polypropylene to suit the seat code. Fit new seats with new balls if the sealing edge is grooved, chipped or chemically attacked. | |
| Wear & Consumable Parts | ||
| Overlay Diaphragm (item 18) | The PTFE face that sits on the fluid side of a Santoprene or neoprene backup diaphragm for aggressive chemicals. Renew it with the backup diaphragm whenever it is creased, pin-holed or worn through. | |
| Seal, Check Valve Assembly (item 37) | PTFE seals either side of each ball retainer and seat stack in the outer chambers. Fit new ones each time the check valves are taken apart, or if product weeps from the joints. | |
| Seal, Manifold (item 36) | Four PTFE seals sit between the S20 manifolds and their elbows. Renew whenever the manifolds are removed, for example when converting to dual porting, or if there is a leak at the manifold joint. | |
| Sleeve and Spool Set (item 1-A) | The matched-ground sleeve and spool inside the main air valve that switch air from side to side. They are a lapped pair and must be changed together if the pump stalls or blows air through the exhaust. | |
| Pilot Valve Assembly (item 2) | Signals the main air valve to change over at the end of each stroke. Rebuild or change it if the pump cycles once and stops or strokes erratically; sleeve (755.052.000) and spool (775.055.000) are listed separately. | |
| Seal, U-Cup and Bumper (items 35, 5) | The nitrile U-cups seal the diaphragm rod through the intermediate and the bumpers cushion the inner plates. Sandpiper suggests a full centre-section rebuild after any diaphragm failure. | |
| Muffler (item 1-F) | The encapsulated exhaust muffler on the air valve; conductive pumps use the threaded muffler. Clean or change it if it is blocked, iced up or soaked with product. | |
| Other Core Parts | ||
| Chamber, Outer (item 16) | The moulded fluid chamber on each side that holds the ball valves. Replace if cracked, crazed by UV or chemical attack, or if the seat pockets are worn; the suffix must match the wetted material code. | |
| Manifold and Elbows (items 25, 19, 20) | The 2" universal-flange manifolds with their discharge and suction elbows, moulded in the pump’s wetted plastic. Change any that are cracked at the flange or distorted from over-tightening. | |
| Diaphragm Plates, Inner and Outer (items 29, 30) | Clamp each diaphragm to the rod; the outer plate is wetted and matches the pump material. Replace plates that are cracked or worn to a sharp edge, which cuts diaphragms; bonded PTFE builds use inner plate 612.227.150. | |
| Rod, Diaphragm (item 34) | Connects the two diaphragm assemblies through the centre section. Replace if it is scored, worn or bent, as surface damage chews up the bushings and U-cup seals. | |
| Intermediate Assembly (item 4) | The centre block that carries the rod seals, plunger bushings and actuator plungers and links the two inner chambers. Replace if the bores are worn oval or the housing is cracked. | |
| Air Valve Assembly (item 1) | The complete main air distribution valve: body, sleeve and spool, end caps and muffler. Order the full assembly if the body is cracked; piped-exhaust, stroke-indicator and PTFE-coated hardware versions are listed. | |
How we confirm the exact part: Sandpiper S20 Non-Metallic parts depend on the wetted material, the diaphragm/check valve code, the valve seat material and the non-wetted material, which all sit in the model number. The item and part numbers shown are as printed in the Sandpiper S20 Non-Metallic Design Level 3 service manual, where the last three digits of each part number give the material (e.g. .520 PVDF, .552 polypropylene, .557 conductive polypropylene). A nameplate such as S20B3P1PPUS000 reads as a 2" ball valve pump in polypropylene with Santoprene diaphragms and balls, polypropylene seats, glass-filled polypropylene centre section, universal flanges and standard style. Tick the items above and attach a nameplate photo so we can confirm the right S20 parts before quoting.
Models
The S20 model code reads S + 20 + B (ball valve) + 3 (design level), then wetted material (K PVDF, P polypropylene, C conductive polypropylene), diaphragm/check valve code, seat material (K or P), non-wetted material (C, P or 1), porting (U universal flange; 7, 8, 9 dual porting), pump style and option codes, e.g. S20B3K1KPUS000. The builds below follow the manual’s nomenclature.
Models & Key Specifications
| Diaphragm/check code | Wet End Kit | Diaphragm (17) | Overlay (18) | Check ball (3) |
|---|---|---|---|---|
| 1 Santoprene/Santoprene | 476.257.354 | 286.005.354 | – | 050.038.354 |
| B Nitrile/Nitrile | 476.257.360 | 286.005.360 | – | 050.038.360 |
| N Neoprene/Neoprene | 476.257.365 | 286.005.365 | – | 050.038.365 |
| C FKM/PTFE | 476.257.633 | 286.005.363 | – | 050.038.600 |
| G PTFE-Neoprene backup/PTFE | 476.257.635 | 286.005.365 | 286.119.600 | 050.038.600 |
| 2 PTFE-Santoprene backup/PTFE | 476.257.654 | 286.005.354 | 286.119.600 | 050.038.600 |
| Z One-piece bonded/PTFE | 476.257.659 | 286.114.000 | – | 050.038.600 |
| M Santoprene/PTFE | – | 286.005.354 | – | 050.038.600 |
| 6 Spill containment, PTFE | 476.258.640 | 286.120.600 pumping + 286.005.365 driver | 286.119.600 | 050.038.600 |
| Spill containment, Santoprene | 476.258.354 | 286.036.354 pumping + 286.005.354 driver | – | 050.038.354 |
Part numbers as printed in the Sandpiper S20 Non-Metallic Design Level 3 service manual (s20nmdl3sm-rev0726). Air End Kit 476.253.000 (476.253.559 for conductive polypropylene). Check valve seats (item 38): 722.075.520 PVDF, 722.075.552 polypropylene. PTFE seals: check valve 720.041.600, manifold 720.038.600. Field conversion kit 475-256-000 changes a PTFE overlay build to one-piece bonded diaphragms (286-114-000 plus inner plates 612-227-150). Manual figures: 2" universal flange (ANSI 125# or PN10 50 mm DIN), 0–605 L/min, heads to 7 bar (70 m), max operating pressure 7 bar, solids to 17 mm, 1.73 L per stroke, 3/4" NPT air inlet, 1" NPT exhaust; shipping weight 43 kg polypropylene, 45 kg conductive polypropylene, 59 kg PVDF. Operating limits: polypropylene 0–82 °C, PVDF −18–121 °C. Individual diaphragm, check valve and seat numbers are grouped by the material code at the end of each part number; we confirm the exact Wet End Kit for your build from the nameplate at quote.
Troubleshooting
Pump cycles once and stops
Likely cause: system pressure at or above the air supply (deadhead), air valve or intermediate gaskets fitted with the holes out of line, or a bent or missing actuator plunger. Action: raise the inlet air pressure, refit the gaskets with the holes aligned and pull the pilot valve to check the actuator plungers (item 31).
Pump will not run or cycle
Likely cause: too much line lubrication, not enough air, a blocked muffler, a closed discharge or a fault in the main air valve or pilot valve. Action: turn the lubricator down or off, check air line size and compressor capacity, clean or de-ice the muffler and strip the air valve and pilot valve (Air End Kit).
Pump cycles but will not prime or gives no flow
Likely cause: cavitation, balls not seating or missing, worn or chemically attacked balls and seats, a blocked suction or an air leak on the suction side. Action: move the pump closer to the product, clear the check valve pockets, check all suction gaskets and replace the balls (item 3) and seats (item 38) if worn.
Running sluggish, stalling or low flow
Likely cause: icing in the exhaust, clogged manifolds, undersized suction or air lines, or air supply set higher than the system needs so the fluid cavitates. Action: de-ice the muffler and fit a point-of-use air dryer, clean the manifolds, upsize the lines and back off the inlet air pressure and volume.
Product coming out of the exhaust
Likely cause: a ruptured diaphragm, loose diaphragm plates, or a diaphragm stretched at the centre or bolt holes from excess pressure or chemical attack. Action: fit new diaphragms (item 17) and overlays where used, torque the plates correctly and rebuild the centre section with the Air End Kit.
Diaphragms failing early
Likely cause: cavitation, too much flooded suction pressure, a material not suited to the product or temperature, or plates fitted backwards or worn sharp. Action: enlarge the suction pipe or lower the inlet head, recheck the diaphragm material against Sandpiper’s chemical resistance chart and fit new plates (items 29, 30) the right way round.
Request for Quotation
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Not sure which parts? Just send a photo of the nameplate or part below.