Sandpiper HDF2 Heavy Duty Flap Pumps
Spare Parts for Sandpiper HDF2 2" Heavy Duty Flap Valve Diaphragm Pumps
Product Summary
Genuine OEM spare parts for the Sandpiper HDF2 2" heavy duty flap valve air-operated double diaphragm (AODD) pump and its BSPT-ported twin, the HDF50, which pass solids up to 45 mm in mine dewatering, sump, slurry and wastewater sludge duties across Australia. Wet End Kits, flap valves, hinge and wear pads, diaphragms and the air valve are all listed by part number in the Sandpiper Design Level 6 manual, so tick what you need and we’ll match them to your nameplate, such as HDF2DB6A.
Spare Parts List
✓ Tick the parts you need. Sandpiper HDF2 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 wet-side overhaul set for the HDF2: two diaphragms, four flaps, four hinge pads, two wear pads and the sealing washers, all in your elastomer. The first thing to order when the flaps stop sealing or a diaphragm splits. | |
| Air End Kit | Rebuilds the air side: main valve sleeve and spool set, pilot valve body assembly, bumpers, bushings, gaskets, O-rings, seals and plungers. Fit when the pump stalls, short-strokes or leaks air at the exhaust. | |
| Air End Refurbishment Kit | The lighter air-side set without the sleeve/spool or pilot body: bumpers, bushings, gaskets, O-rings, seals, plungers and retaining rings. Suits a routine air-end service where the valve bores are still in good order. | |
| Diaphragm (item 19) | Flexes back and forth to fill and empty each liquid chamber. Swap both at once if either is split, stretched around the bolt holes or chemically attacked, or if product shows at the exhaust. | |
| Flap Valve Assembly (item 22) | The hinged flaps that act as the check valves on suction and discharge, letting large solids through where a ball pump would choke. Renew when flow falls away or the pump will not hold prime. | |
| Wear & Consumable Parts | ||
| Check Valve Seat (item 42) | The elastomer seat each flap closes against. A grooved or torn seat lets slurry slip back, so fit new seats along with new flaps. | |
| Hinge Pad (item 31) | Cushions the hinge end of each flap where it is clamped in place. Change it when it is flattened, cracked or hardened, normally at every flap change. | |
| Wear Pad (item 32) | A sacrificial pad that protects the chamber from abrasive solids hitting the flap area. Replace once it is worn thin or gouged. | |
| Sealing Ring (item 39) | Seals the manifold and elbow joints to the outer chambers. Renew whenever the wet end has been split, or if the pump weeps at a manifold joint or sucks air. | |
| Diaphragm Bumper (item 7) | Stops the diaphragm plate striking the intermediate at the end of each stroke. Fit new bumpers when the diaphragms are changed or if the pump knocks hard. | |
| Air Valve & Pilot Valve Gaskets (items 23, 24) | Seal the pilot valve and main air valve to the intermediate. A gasket fitted with its holes misaligned can stop the pump after one stroke, so renew both whenever the air end is off. | |
| Metal Muffler (item 26) | Quietens the air exhaust. Clean or replace it if it is blocked or iced, and check for a burst diaphragm if product appears at the muffler. | |
| Other Core Parts | ||
| Air Valve Assembly (item 1) | The no-lube main directional valve that switches air between the two diaphragms; sleeve and spool (031.012.000) are a matched pair. Replace the assembly if the body is damaged or the bore is scored. | |
| Pilot Valve Assembly (item 3) | Signals the main air valve to shift at the end of each stroke via the actuator plungers. Replace if the sleeve, spool or O-rings are worn and the pump hesitates or stalls. | |
| Diaphragm Plates, Inner & Outer (items 33, 34) | Clamp each diaphragm onto the rod. Replace if bent, scaled or if the outer plate has worn to a sharp edge, which cuts new diaphragms. | |
| Diaphragm Rod (item 40) | Links the two diaphragm assemblies through the intermediate. Replace if scored or marked, as a damaged rod wears the bushings and U-cup seals. | |
| Outer Chamber (item 18) | The liquid chambers that carry slurry past the flaps; supplied with plugs and studs. Replace if eroded thin, cracked or pitted. | |
| Manifolds & Elbows (items 20, 21, 25) | Route product into and out of the chambers in aluminium, cast iron or stainless. Replace a cracked or worn-through casting matched to your wetted code. | |
How we confirm the exact part: Item and part numbers on this page are as printed in the Sandpiper HDF2/HDF50 Design Level 6 service manual. The nameplate model code sets the materials: for example HDF2DB6A reads as HD (heavy duty), F (flap), 2 (2" size), D (top suction, bottom discharge), B (Nitrile diaphragms and flaps), 6 (design level) and A (aluminium wetted, aluminium air). Tick the items above and add a nameplate photo, and we’ll confirm the right parts for your pump.
Models
Read the HDF2 model code left to right: series (HD), design (F for flap), size (2 for NPT or 50 for BSPT), options, discharge porting, diaphragm/valve elastomer letter, design level and finally the construction code that sets the wetted and air-side metals. The builds below are the construction codes in the manual.
Models & Key Specifications
| Elastomer (code) | Wet End Kit | Diaphragm (19) | Flap Valve (22) | Hinge Pad (31) | Check Valve Seat (42) |
|---|---|---|---|---|---|
| Nitrile / Buna (B) | 476.270.360 | 286.007.360 | 338.005.360 | 570.001.360 | 722.070.360 |
| FKM (V) | 476.270.363 | 286.007.363 | 338.005.363 | 570.001.363 | 722.070.363 |
| EPDM (I) | 476.270.364 | 286.007.364 | 338.005.364 | 570.001.364 | 722.070.364 |
| Neoprene (N) | 476.270.365 | 286.007.365 | 338.005.365 | 570.001.365 | 722.070.365 |
| Neoprene – Urethane (A) | 476.270.632 | 286.007.365 | 338.010.357 | 570.001.365 | 722.070.365 |
| Hytrel (R) | 476.270.356 | 286.007.356 | 338.010.356 | 570.001.365 | 722.070.365 |
| Santoprene (P) | 476.270.643 | 286.007.354 | 338.010.354 | 570.001.364 | 722.070.364 |
| Air end (all builds) | Air End Kit 476.247.000 | Refurb Kit 476.314.000 | Air valve: 031.019.156 (Al centre) / 031.019.010 (CI centre) | Pilot valve 095.073.001 | Sleeve & spool 031.012.000 |
Part numbers as printed in the Sandpiper HDF2/HDF50 service manual (Design Level 6, rev 0625). Wear pads (item 32) follow the hinge pad material: 570.009.360 Buna, .363 FKM, .364 EPDM/Santoprene, .365 Neoprene/Hytrel/Urethane. Parts that change with the wetted metal: outer chamber 196.002.157NS (aluminium), 196.002.010NS (cast iron), 196.002.110NS (stainless); manifold 518.001.157 / .010 / .110; outer diaphragm plate 612.008.330 (aluminium and cast iron) or 612.096.110 (stainless). Intermediate and inner chambers follow the centre: 114.002.156 / 196.001.157 aluminium, 114.002.010 / 196.001.010 cast iron. Manual figures: 0–787 L/min, 8.6 bar maximum operating pressure, solids to 45 mm, 1.8 L per stroke, ¾" NPT air inlet, 1" NPT exhaust; shipping weight 39.9 kg aluminium, 59 kg cast iron, 63.5 kg stainless. 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 makes one stroke then stops
Likely cause: system pressure at or above the air supply (deadhead), air valve or intermediate gaskets fitted with holes out of line, or a bent or missing actuator plunger. Action: raise the inlet air pressure, refit the gaskets (items 23, 24) with holes aligned and inspect the actuator plungers (item 37) behind the pilot valve.
Pump will not cycle at all
Likely cause: too little air volume or pressure, too much line lubricant, a blocked or iced muffler, a closed discharge valve or a chamber packed with solids. Action: check air line size and compressor capacity, turn the lubricator down or remove it, clean the muffler (item 26) and clear the discharge line and chambers.
Pump cycles but will not prime or move product
Likely cause: a flap held open by debris, worn flaps or seats, a blocked suction line, suction-side air leaks or too much suction lift. Action: open the wet end and clear the flap pockets, fit new flaps (item 22) and seats (item 42) if worn, and check suction gaskets and sealing rings (item 39).
Running sluggish or stalling
Likely cause: icing in the exhaust, over-lubrication, cavitation from an undersized suction line, or an undersized air supply line. Action: de-ice the muffler and fit a point-of-use air dryer, reduce air to stop fast cycling, and size the suction and air lines at least to the pump connections.
Product coming out of the air exhaust
Likely cause: a ruptured diaphragm, loose diaphragm plates, or a diaphragm stretched at the centre or bolt holes from excess pressure. Action: replace both diaphragms (item 19), check the plates for damage and tighten them to torque, and review inlet and air pressures.
Diaphragms failing early
Likely cause: cavitation, too much flooded suction pressure, an elastomer that does not suit the product, or plates fitted backwards or worn to a sharp edge. Action: enlarge the suction pipe, lower the inlet head or fit a back-pressure device, pick a better-suited elastomer, and renew worn plates (items 33, 34).
Request for Quotation
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Not sure which parts? Just send a photo of the nameplate or part below.