The Multiquip SP3351A1 Waterbox & Groove Pin Assembly is a genuine OEM replacement designed for STOW Diaphragm Pump models SDP-3, SDP-2, and CA90749. As a direct OEM component sourced from Multiquip, it is manufactured to the exact specifications required by these pumps, ensuring a correct, trouble-free installation. This assembly is the right choice when restoring full pumping performance after waterbox wear or groove pin failure. Confirm your model code against SDP-3, SDP-2, or CA90749 before ordering to ensure fitment.
Key Features
- Genuine OEM Construction — Manufactured to Multiquip's original design specs for the waterbox and groove pin interface, delivering the correct sealing geometry and pin retention that aftermarket alternatives may not replicate.
- Complete Assembly — Supplied as a matched waterbox and groove pin unit, so both interdependent components are replaced together for a proper, lasting repair.
- Direct Fit for STOW Diaphragm Pumps — Verified for SDP-3, SDP-2, and CA90749 models; installs into the existing pump housing without modification to mounting points or hardware.
- Restores Full Pumping Efficiency — A worn or damaged waterbox allows fluid bypass and pressure loss across the diaphragm chamber; replacing it with SP3351A1 returns the pump to consistent, rated flow output.
- Fluid Containment Integrity — The groove pin retains critical internal components under pumping pressure; a failed pin can cause immediate loss of prime and uncontrolled fluid escape, making timely replacement essential.
The waterbox is the fluid chamber in a diaphragm pump where suction and discharge valves direct flow on each stroke of the diaphragm. It must maintain a leak-free seal to sustain prime and deliver consistent output pressure. The groove pin secures key internal components within this chamber; if it shears or backs out under operational load, the assembly loses its structural integrity and the pump will fail to move fluid. Replacing both components together as the SP3351A1 assembly ensures the entire fluid-end interface is restored to its original condition.
Part Details
| Part Number | SP3351A1 |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | Waterbox & Groove Pin Assembly |
Compatibility & Fitment
| Name | Model |
|---|---|
| STOW Diaphragm Pumps | SDP-3 |
| STOW Diaphragm Pumps | CA90749 |
| STOW Diaphragm Pumps | SDP-2 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
Core Cut
Waterbox & Spring Pin 2" Waterbox & Spring Pin Assembly | 2504814
