Yamada 770550 Check Valve Ball 50 mm, neoprene for NDP-40
The Yamada 770550 is the genuine check valve ball for NDP-40 Series pumps. Each fluid chamber has an inlet ball and an outlet ball, and they are what make the pump one way: the diaphragm creates suction and pressure, and the balls decide which direction the fluid is allowed to travel.
Balls wear out of round, they develop flats where they seat, and abrasive product polishes them undersize. Any of those lets fluid slip back past the ball on the return stroke, which shows up as reduced flow, a pump that cycles quickly without delivering, or loss of suction lift. Because the ball and the seat wear together, it is normal practice to replace both at the same time rather than putting a new ball onto a grooved seat.
Key Features
- Genuine Yamada replacement check valve ball
- Material: neoprene
- Fits NDP-40 Series pumps
- 4 per pump - two on the suction side and two on the discharge side
- Restores check valve sealing and suction lift
- Replace balls and valve seats as a matched set
Applications
- NDP-40 Series pumps
- Restoring lost flow and slow priming
- Rebuilding a wet end after abrasive service
- Scheduled liquid end overhauls
- Replacing balls worn flat or undersize
- Marine, industrial and chemical transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 770550
- Part Type: Check Valve Ball
- Material: Neoprene
- Nominal Size: 50 mm
- Fits: NDP-40 Series pumps
- Quantity Used: 4 per pump
- Series Port Size: 1-1/2 in on the NDP-40 Series
- Condition: New
Frequently Asked Questions
Q: How do I tell if a ball is worn?
Roll it on a flat surface and look along the edge. A worn ball wobbles or shows a dull flat band where it has been seating, and it will usually be visibly smaller than a new one when the two are held together.
Q: Do I have to replace the seats as well?
It is strongly advised. The ball and seat bed into each other, so a new ball on an old grooved seat seals against a worn profile and wears quickly to match it.
Q: Why does the pump lose prime overnight?
Usually a leaking suction check ball. With the pump stopped, a ball that no longer seals lets the column of liquid in the suction line drain back, so the pump has to lift dry again from cold.
Q: Can I run a different ball material than the pump was built with?
You can, provided it is compatible with the fluid and rated for the temperature. Weight matters too, since a ball that is too light is slow to reseat at high cycle rates.
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 check valve ball.
CLRMarine
