Yamada 771241 Packing for NDP-20 to NDP-32
The Yamada 771241 is a factory packing used in NDP-20, NDP-25 and NDP-32 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.
Fit the packing the right way round. A V-profile seal is directional - the open side faces the pressure so that pressure energizes the lip against the shaft. Installed backwards it will leak from the first stroke, which is a frustrating fault to chase after a full rebuild.
Key Features
- Genuine Yamada replacement packing
- Fits NDP-20, NDP-25 and NDP-32 Series pumps
- One 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-20, NDP-25 and NDP-32 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: 771241
- Part Type: Packing
- Fits: NDP-20, NDP-25 and NDP-32 Series pumps
- Quantity Used: One per pump
- Series Port Size: 1 in on the NDP-25 Series
- Condition: New
Frequently Asked Questions
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.
Q: Does a seal ring do the same job?
A seal ring seals the air valve spool rather than the center rod, but the principle is the same - a dynamic seal on a sliding surface, and one of the first parts to replace when the air motor misbehaves.
Q: How do I know the packing is worn?
Air consumption rises, the pump cycles more slowly for the same air pressure, and there is often audible air escaping around the center block. Visually, the sealing lip will be rounded or glazed rather than sharp.
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.
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 packing.
CLRMarine
