Yamada 771484 Seal Ring for NDP-15
The Yamada 771484 is a factory seal ring used in NDP-15 Series pumps. It seals against a moving surface rather than a static joint, which is why it wears out on a schedule while the static seals around it can last for years.
Worn packing shows itself as air blowing where it should not - out of the center block, into the wet side, or simply as a pump that will not complete a stroke because the air is escaping faster than the valve can supply it. Air consumption climbs and the pump feels sluggish long before anything actually stops working.
Key Features
- Genuine Yamada replacement seal ring
- Fits NDP-15 Series pumps
- 5 per pump
- Dynamic seal for the reciprocating parts of the air motor
- Restores air motor efficiency and reduces air consumption
- Fit with the sealing lip facing the pressure
Applications
- NDP-15 Series pumps
- Air motor overhauls and seal kit service
- Curing high air consumption and sluggish cycling
- Repairing air leakage at the center block
- Rebuilds after a diaphragm failure contaminated the air side
- Marine, industrial and transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 771484
- Part Type: Seal Ring
- Fits: NDP-15 Series pumps
- Quantity Used: 5 per pump
- Series Port Size: 1/2 in on the NDP-15 Series
- Condition: New
Frequently Asked Questions
Q: Which way round does it go?
The open side of the V faces the pressure, so that air pressure pushes the lip harder against the shaft. Note the orientation of the old one as it comes out.
Q: Can I fit new packing to a scored rod?
No, or at least not for long. A ridge or score on the shaft cuts the new seal quickly. Replace or dress the shaft first.
Q: Why does the packing wear out faster than the O-rings around it?
Because it seals against a moving surface. Every stroke slides the shaft through it, so it accumulates wear in a way that a static seal never does.
Q: Should the throat bearing be changed at the same time?
Inspect it. A worn bearing lets the shaft move off center and loads one side of the packing, so replacing the seal without checking the bearing usually means doing the job twice.
Not sure this is the right part? Send us a Picture of the Pump Plate on your pump and the CLR Marine team will confirm the correct seal ring.
CLRMarine
