Heavy Duty Flap Pumps, Metallic & Non-Metallic

Engineered for the Most Demanding Solids-Handling Applications

When your application involves large, abrasive, or fast-settling solids, you need a pump that won’t clog or wear out quickly. SANDPIPER’s Heavy Duty Flap Pumps, available in both metallic and non-metallic models, are built to move even the toughest fluids with confidence and control.

These air-operated double-diaphragm (AODD) pumps are designed with a full flow-through, bottom-discharge design and swing-style flap valves that pass solids up to 3" in diameter, keeping your system running by reducing clogs and protecting components. 

Key Features:

• Sizes: 1 - 4" sizes (25 - 102 mm)
• Flow: 70 - 310 gpm (265 - 1173 lpm)
• Solids Handling: 1 - 3” (25 - 76 mm)
• Construction: Aluminum, Cast Iron, Stainless Steel, Polypropylene
• Elastomers: (Diaphragms & Flaps) Nitrile, Neoprene, Hytrel®, Santoprene®, Fluorocarbon, EPDM, Urethane
• Bottom-discharge porting clears solids efficiently, preventing buildup and wear
• Dry prime suction lift up to 24 ft., 5% higher than typical ball valve pumps
• Quick access to serviceable components for faster maintenance and less downtime
• ESADS+Plus air distribution system allows easy in-line maintenance

What Makes Flap Pumps Different?

Unlike standard ball valve pumps, flap valves create a more direct path for challenging materials to flow. This makes Heavy Duty Flap Pumps especially effective when:

• Solids are too large for ball valves
• Material settles quickly or becomes compacted
• You need vertical lift or long suction lines
• You want fewer wear parts exposed to abrasive slurries

Metallic vs. Non-Metallic Models

• Metallic Pumps (Aluminum, Cast Iron, Stainless Steel): Best for rugged industrial environments where abrasion or impact resistance is key
• Non-Metallic Pumps (Polypropylene): Best for chemical compatibility, corrosion resistance, and lighter-weight installations

All models feature all-bolted construction for leak-free performance and are backed by SANDPIPER’s commitment to long-term reliability. No matter which material you choose, you’ll get long-lasting performance, simplified maintenance, and fewer surprises on the job.