U.S. Seal PS-4280 Premium Shaft Seal Assembly (5/8″ Shaft, Wet-End Pump Seal)

The U.S. Seal PS-4280 is a heavy-duty mechanical shaft seal designed for longevity, chemical resistance, and reliable sealing in pool and spa pumps. It replaces the wet-end seal where the motor shaft penetrates the pump housing — a critical point to prevent leaks and maintain proper suction.

Key Features

• 5/8″ impeller shaft diameter — fits many common pool and spa pumps using this shaft size.
• Premium materials — Viton elastomer, carbon-graphite primary ring, ceramic sealing face, and stainless-steel hardware for enhanced chemical, heat, and wear resistance.
• Reverse-style mechanical seal — designed for wet-end installation to provide strong, pressure-resistant sealing under operating conditions.
• Ideal for saltwater, ozone, or bromine systems — superior chemical resistance improves durability compared to standard seals.
• Broad compatibility — suitable for many popular pump brands and models, reducing the need for multiple part numbers.

Specifications

• Manufacturer: U.S. Seal
• Part Number: PS-4280
• Shaft Size: 5/8″ (0.625″) impeller shaft
• Seal Type: Mechanical shaft seal (reverse-style, wet-end application)
• Seal Materials: Viton elastomer, carbon-graphite ring, ceramic sealing face, stainless-steel hardware
• Applications: Replacement seal for pool and spa pumps, including saltwater and chemically treated systems

When to Use / Replace

Install PS-4280 during pump rebuilds, seal replacements, or when existing wet-end seals show leaks, wear, or chemical degradation. Because this seal is built for demanding conditions — including salt, ozone, and high-bather load systems — it’s especially useful if your pool uses aggressive sanitizers or operates year-round.

Installation Tips

• Shut off power and drain the pump completely before disassembly.
• Thoroughly clean and inspect the shaft and seal housing — even minor nicks or corrosion can lead to seal failure.
• Lightly lubricate the new seal’s ceramic face with a pool-safe lubricant to avoid dry-start wear. Avoid petroleum-based oils that can degrade the elastomer.
• Seat the new seal carefully, ensuring flat, even contact. Reassemble the pump wet-end per manufacturer instructions, and test under pressure to verify sealing before full operation.
• Inspect periodically for leaks, especially after prolonged shutdowns or chemical imbalance events. Prompt replacement can prevent costly pump or motor damage.

Why Choose PS-4280

The U.S. Seal PS-4280 stands out for its premium materials and chemical resilience — making it a reliable, long-lasting choice for pool and spa pumps. Whether you’re performing routine maintenance or seeking a durable upgrade for saltwater or heavily treated systems, this seal helps ensure tight, leak-free operation and extends pump life by protecting internal components from water intrusion and corrosion.